Methods and apparatus of improving inter-sector and/or inter-cell handoffs in a multi-carrier wireless communications system
43 claims: 4 independent, 39 dependent
- 1第1基地局トランスミッタを操作する方法であって:i)前記方法は、前記第1基地局トランスミッタが第2周波数帯域内に送信しない第1期間に第1周波数帯域内に送信するように前記第1基地局トランスミッタを操作するステップを含んでおり;ii)前記方法は、前記第1期間より短い第2期間に 、前記第1周波数帯域内の送信パワーより大きなパワーで、 第2周波数帯域内に送信するように前記第1基地局トランスミッタを操作するステップを含んでおり、前記第1基地 局は 、前記第1周波数帯域内に送信する期間の1/Nより短い期間の間前記第2周波数帯域内に送信し、このNは2より大きな正の値であり;iii)前記方法は、ステップi及びiiを反復するステップを含む、方法。
- 2ステップi及びiiは、前記第1トランスミッタが前記第1周波数帯域内に送信する時間の長さが前記第2周波数帯域内に送信する時間の長さより平均で長いように、定期的間隔を置いて反復される、請求項1に記載の方法。
- 3前記第2期間に前記第1基地局トランスミッタは前記第1周波数帯域内に送信しない、請求項1に記載の方法。
- 4前記第1トランスミッタは、時間に関して、前記第1トランスミッタが前記第2周波数帯域内に送信するより少なくとも20倍長く前記第1周波数帯域内に送信する、請求項1に記載の方法。
- 5前記第1及び第2の周波数帯域は同じサイズである、請求項1に記載の方法。
- 6第2期間に第2周波数帯域内に送信するように前記第1基地局トランスミッタを操作することは、送信されるパワーの少なくとも60%を、前記第2周波数帯域の1/5未満を占める1つ以上のトーンに集中することを含む、請求項5に記載の方法。
- 7第2期間に第2周波数帯域内に送信するように前記第1基地局トランスミッタを操作することは、先行する1秒の時間間隔においてトーンを送信するために使用される平均トーン当たりパワーの少なくとも20倍で1つのトーンを送信することを含む、請求項5に記載の方法。
- 8前記第2期間に前記第1周波数帯域内に送信するように前記第1基地局トランスミッタを操作することを更に含む、請求項1に記載の方法。
- 9第1周波数帯域内に送信するステップiは、複数の別々のトーンでユーザデータを前記第1周波数帯域内に送信することを含む、請求項1に記載の方法。
- 10前記ユーザデータは音声、テキスト及びユーザアプリケーションデータのうちの少なくとも1つを含む、請求項9に記載の方法。
- 11第2周波数帯域内に送信するステップiiは、トランスミッタ情報を送信するが特定ユーザ向けデータを送信しないことを含む、請求項9に記載の方法。
- 12前記トランスミッタ情報はセル識別情報及びセクタ識別情報のうちの少なくとも1つを含む、請求項11に記載の方法。
- 13第2周波数帯域内に送信するステップiiは、前記第1周波数帯域内に情報を送信するために使用されるトーンの数より少ないトーンで情報を送信することを含む、請求項11に記載の方法。
- 14前記第2周波数帯域内に情報を送信するために使用されるトーンの前記数は3より少ない、請求項11に記載の方法。
- 15ステップi及びiiは、各々、少なくとも1つの複素シンボルを含む少なくとも1つのOFDM信号を送信することを含む、請求項11に記載の方法。
- 16ステップiiは2つのOFDMシンボルを送信することを含む、請求項15に記載の方法。
- 17前記トランスミッタ情報は少なくとも1つのトーンを用いて送信され、前記第1トランスミッタは、該トランスミッタが前記第1期間に前記第1周波数帯域内にユーザデータを送信するために使用される任意の1つのトーンで送信するのに比して、前記の少なくとも1つのトーンで少なくともM倍のパワー量を送信し、このMは2より大きい正の整数である、請求項11に記載の方法。
- 18前記トランスミッタ情報は少なくとも1つのトーンを用いて送信され、前記第1トランスミッタは先行する1秒の時間間隔の間にトーンを送信するために使用された平均トーン当たりパワーの少なくとも20倍を用いて前記の少なくとも1つのトーンを送信する、請求項11に記載の方法。
- 19Mは少なくとも5である、請求項17に記載の方法。
- 20前記第1期間は複数のシンボル送信期間を含み、前記第2期間は前記第1期間より少ないシンボル送信期間を含む、請求項15に記載の方法。
- 21iii)前記方法は、第2基地局トランスミッタが前記第1周波数帯域内に送信しない第3期間に前記第2周波数帯域内に送信するように前記第2基地局トランスミッタを操作するステップを更に含み;iv)前記方法は、前記第3期間より短い第4期間に前記第1周波数帯域内に送信するように前記第2基地局トランスミッタを操作するステップを更に含み、前記第2基地局トランスミッタが前記第2周波数帯域内に送信する期間の1/Nより短い期間の間前記第2基地局トランスミッタは前記第1周波数帯域内に送信し;v)前記方法は、ステップiii及びivを反復するステップを更に含む、請求項1に記載の方法。
- 22ステップiii及びivの反復は、定期的間隔を置いて複数回実行される、請求項21に記載の方法。
- 23前記第4期間には前記第2基地局トランスミッタは前記第2周波数帯域内に送信しない、請求項21に記載の方法。
- 24前記第3期間に前記第2基地局トランスミッタはテキスト及び音声データのうちの少なくとも1つを含むユーザデータを送信する、請求項21に記載の方法。
- 25前記第2基地局トランスミッタは前記第4期間に基地局情報を送信するがユーザデータは送信しない、請求項24に記載の方法。
- 26前記第1及び第2の基地局トランスミッタは別々の物理的に隣接するセル内にある、請求項25に記載の方法。
- 27前記第1及び第2の基地局トランスミッタは同じセル内にある、請求項25に記載の方法。
- 28前記の第1及び第2のトランスミッタはセクタトランスミッタであり;前記第1基地局トランスミッタを使用するステップiiの実行と前記第2基地局トランスミッタを使用するステップivの実行との間には一定の時間オフセットがある、請求項27に記載の方法。
- 29基地局であって、該基地局は:第1及び第2の周波数帯域内に信号を送信するための第1トランスミッタと;前記第1トランスミッタが第2周波数帯域内に送信しない第1期間に第1周波数帯域内に送信し;少なくとも前記第1期間の1/5より短い第2期間に 、前記第1周波数帯域内の送信パワーよりも大きなパワーで、 第2周波数帯域内に送信するように前記第1トランスミッタを制御するための手段と;を含む、基地局。
- 30前記第2期間に前記第1トランスミッタは前記第1周波数帯域内に送信しない、請求項29に記載の基地局。
- 31前記第1トランスミッタ制御手段は、前記第2期間に前記第1周波数帯域内に送信するように前記第1トランスミッタを制御する、請求項29に記載の基地局。
- 32前記の第1及び第2の周波数帯域は同じサイズである、請求項29に記載の基地局。
- 33前記 第1 基地局は:送信するべく記憶されたユーザデータのセットを更に含み、前記の記憶されたユーザデータのセットは音声、テキスト及びユーザアプリケーションデータのうちの少なくとも1つを含み;前記第1期間に前記第1周波数帯域内に送信するように前記第1トランスミッタを制御することは、前記の記憶されているユーザデータのうちの少なくとも或るものを前記第1周波数帯域内に送信するように前記トランスミッタを制御することを含む;請求項29に記載の基地局。
- 34前記基地局は:トランスミッタ情報を更に含んでおり;前記第2周波数帯域内に送信するように前記第1トランスミッタを制御することは、前記第2周波数帯域内に如何なるユーザデータも送信することなく前記トランスミッタ情報のうちの少なくとも或るものを送信するように前記トランスミッタを制御することを含む;請求項33に記載の基地局。
- 35前記第1トランスミッタ制御手段は、前記第1期間に前記第1周波数帯域内に送信するよりも少ない信号トーンを前記第2期間に前記第2周波数帯域内に送信するように前記トランスミッタを制御する、請求項34に記載の基地局。
- 36前記第2期間に前記第1トランスミッタによって4個より少ない信号トーンが前記第2周波数帯域内に送信される、請求項34に記載の基地局。
- 37前記第2周波数帯域内に送信される前記信号トーンは、前記第1期間に前記第1周波数帯域内にユーザデータを送信するために使用される最大パワーの少なくとも2倍で送信される、請求項36に記載の基地局。
- 38前記基地局は、前記の第1及び第2の周波数帯域内に信号を送信するための第2トランスミッタを更に含み;前記基地局は、前記第2トランスミッタを制御するための手段を更に含み;前記手段は、前記第2トランスミッタが前記第1周波数帯域内に送信しない第3期間 に前 記第2周波数帯域内に送信するように前記第2トランスミッタを制御し;前記手段は、前記第3期間より短い第4期間 に前 記第1周波数帯域内に送信するように前記第2トランスミッタを制御し、前記第2トランスミッタが前記第2周波数帯域内に送信する期間の1/Nより短い期間の間前記第1周波数帯域内に送信するように前記第2トランスミッタを制御する;請求項29に記載の基地局。
- 39前記の第1及び第2のトランスミッタは別々の物理的に隣接するセルの中にある、請求項38に記載の基地局。
- 40前記の第1及び第2のトランスミッタは同じセルの別々のセクタの中にある、請求項38に記載の基地局。
- 41前記第1トランスミッタ制御手段は、前記第1トランスミッタにユーザデータと前記第1トランスミッタに関連するトランスミッタ情報とを前記第1時間間隔に前記第1周波数帯域内に送信させ;前記第1トランスミッタ制御手段は、テキスト或いは音声ユーザデータを除いて前記第1トランスミッタに関連するトランスミッタ情報を前記第2周波数帯域内に送信させる;請求項40に記載の基地局。
- 42前記第2トランスミッタ制御手段は、前記第2トランスミッタにユーザデータと前記第2トランスミッタに関連するトランスミッタ情報とを前記第2周波数帯域内に送信させ;前記第2トランスミッタ制御手段は、テキスト或いは音声ユーザデータを除いて前記第2トランスミッタに関連するトランスミッタ情報を前記第1周波数帯域内に送信させる;請求項41に記載の基地局。
- 43前記第1トランスミッタに関連する前記トランスミッタ情報は第1トランスミッタ識別子であり、前記第2トランスミッタに関連する前記トランスミッタ情報は第2トランスミッタ識別子である、請求項42に記載の基地局。
Independent claims43
84 paragraphs, as filed
The present invention relates to communication systems, and in particular to methods and devices that facilitate the selection of network connection points to be used and / or to perform handoffs.
A cell can contain one or more sectors. A cell that does not have multiple sectors is a single sector cell, that is, it has only one sector. The signal is typically transmitted by a sector transmitter that uses one carrier frequency and a corresponding bandwidth, for example, one or more tones surrounding the carrier frequency. Different cells and / or multiple sectors of a cell often use different frequency bands centered on the carrier frequency used by that sector or cell. In frequency reuse systems, adjacent cells and / or sectors often have different carrier frequencies. In order to receive multiple signals corresponding to one carrier frequency, the wireless terminal device adjusts its receiver, such as a receiver filter, to correspond to the frequency band associated with the carrier frequency to be used. Must. Switching the receiver between multiple carrier frequencies will probably take some time. Therefore, in a receiver with a single filter chain, there may be periods during which the receiver cannot receive information due to the switching process due to transitions between different carriers.
A wireless terminal device, such as a mobile node, that communicates with a base station at a given carrier frequency and travels through a multicarrier system, at any time hands off to a new carrier frequency corresponding to, for example, a new cell and / or sector. You have to decide if you want to transition. As mentioned above, adjacent sectors and / or cells may be using different carrier frequencies, and when crossing a sector or cell boundary, the wireless terminal usually identifies the new carrier frequency and said the new carrier. Must switch to frequency.
Mobile nodes typically listen to one carrier frequency band at a time due to the hardware and cost constraints associated with the receiver. This is because multiple parallel receiver filter chains are practically too expensive for cost reasons. In some known systems, the mobile node waits before switching to another carrier until communication in the operating carrier band used is lost or significantly degraded. In some systems, the wireless terminal device periodically switches its receiver to another carrier band to check for the presence and / or strength of the signal. Unfortunately, the receiver is unable to receive a signal from the carrier currently in use while being switched to look for another carrier. Known methods of determining what carrier to switch to and when to switch to a new carrier waste resources on monitoring and determining communication interruptions, gaps during the handoff process, and / or the appropriate carrier frequency band. It may bring the result.
In light of the above discussion, it should be understood that an improved way of determining when a wireless terminal device should initiate a handoff is needed. Preferably, the new or improved method should not require the mobile node to switch its receiver to another frequency band in order to find the carrier frequency of the adjacent cell or sector.
<p> The present invention provides information that can be used by a receiver of a wireless terminal device to identify a carrier wave being used by a neighboring sector or cell while remaining at its current operating carrier frequency in the neighboring sector and / or cell. Allows you to receive from your base station. It controls the base station transmitters of various sectors and / or cells to periodically transmit signals containing a narrow high power signal component (in terms of frequency) within the frequency band used by the adjacent sector or cell. Achieved by doing.</p><p> In systems using the present invention, base station transmitters of various sectors and / or cells each place a high power signal, referred to in this application as a beacon signal, within the frequency band used by the adjacent sector or cell. Send regularly. A beacon signal is a signal that contains one or more narrow signal components (in terms of frequency), such as a signal tone, that are transmitted at a relatively higher power than other signals, such as a user data signal. In some embodiments, each beacon signal comprises one or more signal components, each of which corresponds to a separate tone. In some embodiments, the beacon signal component is a tone that is 10 times, 20 times, 30 times, or more of the signal energy per average tone of the signal tones used to transmit user data and / or non-beacon control signals. Includes per-signal energy. The frequency of one or more components of a beacon signal is the carrier used by the transmitter that transmitted the beacon to convey the user data, cell identifier and / or sector identifier that corresponds to the transmitter that transmitted that particular beacon signal. Can be used to convey information such as. Some information is transmitted by using a plurality of beacon signals, in which case the frequencies of the plurality of beacon signal components convey, for example, the type of transmitter information described immediately above.</p><p> Although many beacons, such as multiple high power tones, can be transmitted simultaneously, in many embodiments at most one beacon signal is transmitted by the transmitter during any given transmission period, eg, during a symbol transmission period. .. The one beacon signal can include one high power signal tone, or in some embodiments several high power tones. The beacon signal is transmitted by the transmitter during a transmission time corresponding to the OFDM symbol transmission time in one typical OFDM embodiment. However, this is only one representative embodiment, and the transmission time may be different in other embodiments.</p><p> Each beacon signal tone is transmitted, for example, at a predetermined frequency, which allows the frequency of the beacon signal component to be used for transmission information such as cell, sector and / or carrier information. In some embodiments, the beacon signal corresponds to a single tone. Beacon signals may be fixed in terms of frequency, or may be transmitted at different frequencies at different times according to a predetermined pattern, such as a particular hopping sequence corresponding to a cell or sector.</p><p> In various embodiments, the transmitter does not transmit user data when transmitting the beacon signal within the frequency band of the adjacent sector or cell, but in some embodiments the transmitter continues to transmit user data and the beacon signal transmission is the transmitter. In addition to transmitting data signals and / or other signals to the sectors serviced by.</p><p> Beacon signals transmitted within the frequency band of an adjacent cell or sector do not require the mobile node within the adjacent cell or sector to change the frequency band to which the receiver of that mobile node is fitted. Can be detected. Beacon signals have relatively high power levels and are easy to detect. The frequency of the detected beacon signal can be easily determined by the wireless terminal device, for example, based on the energy received at each tone. Beacon frequency detection can be done before the wireless terminal device acquires synchronization information such as carrier frequency or symbol timing associated with the cell or sector in which the beacon signal is transmitted, and the beacon is from an adjacent cell. In many cases, it is often done that way. The frequency of the received beacon signal can be used to determine the sector or cell that transmitted the detected beacon signal, and is actually used as such in various embodiments. By accumulating information about the signal strength of the received beacon signal, such as power, and comparing the strength of the beacon signals corresponding to different sectors, the mobile can determine when to perform the handoff. From the frequency of the received beacon signal that triggered the handoff operation, it is possible to determine to which carrier frequency the handoff should be performed. The carrier frequency of the adjacent sector or cell is determined from the stored information indicating the carrier frequency used by the various sectors and / or cells to transmit the beacon signal.</p><p> The information obtained from the beacon signal transmitted by a neighboring sector or cell within the frequency band of the neighboring sector or cell is that the wireless terminal device in the neighboring sector or cell is approaching the boundary region. When present, it makes it possible to identify when the radio terminal device should perform a handoff and what new carrier frequency should be used after the handoff. This can be achieved without having the radio terminal device switch its receiver to a different frequency band to identify the carrier waves of neighboring sectors and / or cells.</p><p> The length of time a transmitter transmits a beacon signal within the frequency band of an adjacent sector or cell is typically used by the transmitter to convey user data, such as text, video, audio or other user application data. It is only a small part of the time that the transmitter sends user data during the frequency band.</p><p> A number of additional features, advantages and embodiments of the present invention are discussed in the detailed description below.</p>
Each cell contains one base station that sends a separate signal to each sector of the cell. Each cell contains one or more sectors. Separate antennas and / or transmitters can be provided for each sector of the cell. The base station transmits a plurality of beacon signals from each sector of the cell, eg, at different times, according to the present invention. One or more beacons within a frequency band typically used by a particular sector to convey information, such as user data and / or control information for individual wireless terminal devices, to wireless terminal devices within that sector. A signal is transmitted. User data can include text data, voice data and / or other types of user application data. Such beacon signals can be used to convey information such as, for example, sector identifiers, cell identifiers, and / or carrier frequencies used in the sector. According to the present invention, a base station is within a frequency band used, for example, by an adjacent sector or cell to transmit user data and / or control signals corresponding to a particular wireless terminal device within the adjacent sector or cell. A sector transmitter is used to periodically transmit a beacon signal at a given frequency. As a result, the beacon signal can be transmitted within the same frequency band, for example, at different times. To facilitate identification of the sector that is the source of the beacon signal within a particular frequency band, each sector transmits a beacon at a separate predetermined frequency within any given frequency band used by the sector.
To compare the strength of the beacon signal received from adjacent sectors and / or cells with the strength of the beacon signal received from its own current base station sector transmission to determine when to perform the handoff. Can be done. By monitoring and evaluating beacon signals from adjacent sectors / cells in accordance with the present invention, wireless terminal devices often experience interruptions in service or service interruptions that occur in systems where it is difficult to determine the carrier frequency to be used after handoff. A continuous handoff can be performed without interruption.
In one typical OFDM (Orthogonal Frequency Division Multiplexing) embodiment, the beacon signal is realized as a relatively large power signal transmitted in a single tone, eg frequency. The power used to transmit a beacon signal is, in some embodiments, the average power of the maximum power signal tone used to convey a data or pilot signal in the sector corresponding to the transmitter transmitting the beacon signal. Greater than 2 times, and often 5 to 6 times larger.
In certain embodiments, which are not necessarily all embodiments, the power used to transmit the beacon signal is all used to convey the data or pilot signal in the sector from which the beacon is transmitted. More than 20 times the average power per tone of a tone, this power per average tone is associated with a transmission period that precedes the transmission of the beacon signal, for example a transmission period of 1 or 2 seconds. For example, if 100 separate tones were used in that one second period, the average power per tone per second would be the total transmitted power per second divided by 100. One one-second period can include multiple symbol transmission periods. Assuming that one beacon signal is transmitted in one tone in one symbol period, the beacon signal is transmitted during one symbol transmission period in that one second period in certain typical embodiments. It will have more than 20 times the average energy of one tone.
When one beacon signal is transmitted in one typical OFDM embodiment, a significant amount of transmission power is concentrated on one or a few tones, for example the single tone that makes up the beacon signal. This amount of power is sufficient to reliably detect the beacon and is greater than the average power of other non-beacon tones transmitted. Tones that are not used for the beacon signal need not be used and are sometimes not actually used. However, in some cases, tones that are not used to transmit the beacon are still used to transmit other information at power levels lower than the power level of the beacon. In some embodiments, when transmitting a beacon signal within the frequency band used by the adjacent sector, one of the tones used in the frequency band of the sector transmitting the beacon signal is powered. May remain unused by the transmitter in the sector as it concentrates on the beacon signal. However, such restrictions are not mandatory.
FIG. 1 shows a representative three-sector cell 100 corresponding to a base station (BS) 102 implemented according to one representative embodiment of the present invention. BS102 is a sectorized base station. The base station (BS) 102 carries ordinary signals such as user data and control signals at a carrier frequency f.<sub>1</sub>Is used to send within sector 1 106. BS102 has a carrier frequency f<sub>2</sub>Ordinary signal in sector 2 108 and carrier frequency f<sub>3</sub>Is used to send a normal signal into sector 3 110. A radio terminal device (WT) 104 implemented in accordance with the present invention is shown in the boundary area between sector 1 106 and sector 2 108. The WT104 can receive signals, such as one or more beacon signals, from adjacent sector base station transmitters without the need to change the frequency band settings of its receiver. Information received from its own current sector base station transmitter and adjacent sector base station transmitters can be used by the WT104 when making handoff decisions.
FIG. 2 shows three typical cells (cell 1, cell 2, cell 3) in a typical wireless communication system 200 according to the present invention. Each cell contains one base station and three sectors, each of which has a separate carrier frequency (f) for normal communication with wireless terminal equipment within that particular sector.<sub>1</sub>, F<sub>2</sub>, F<sub>3</sub>) And the corresponding frequency band. Same three carrier frequencies f<sub>1</sub>, F<sub>2</sub>, F<sub>3</sub>And the bandwidth associated with each carrier is reused in each cell. Cell 1 202 is the carrier frequency (f)<sub>1</sub>, F<sub>2</sub>, F<sub>3</sub>) Includes base station 1 (BS1) 208 and three sectors (sector 1 214, sector 2 216, sector 3 218), respectively. Cell 2 204 has a carrier frequency (f).<sub>1</sub>, F<sub>2</sub>, F<sub>3</sub>) Includes base station 2 (BS2) 210 and three sectors (sector 1 220, sector 2 222, sector 3 224), respectively. Cell 3 206 is the carrier frequency (f)<sub>1</sub>, F<sub>2</sub>, F<sub>3</sub>) Includes base station 3 (BS3) 212 and three sectors (sector 1 226, sector 2 228, sector 3 230), respectively. FIG. 2 also includes a representative wireless terminal device (WT) 232 implemented in accordance with the present invention. This WT is located on the boundary between sector 1 214 in cell 1202 and sector 2 222 in cell 2 204. The WT232 carries the frequency band setting of its receiver frequency f<sub>1</sub>Without needing to change from the band corresponding to, for example, carrier f<sub>1</sub>Corresponding to receiving signals such as one or more beacon signals from its own cell and / or adjacent cells transmitted from a base station transmitter in a sector adjacent to the frequency band used in sector 1. Can be done. Information received from base station transmitters in its own current sector and adjacent sectors can be used by the WT232 when making handoff decisions.
The WT232 handoff can be performed between different base station sectors in different cells or between different base station sectors in the same cell according to the method of the invention.
The total frequency band in the example of FIG. 2 is divided into three adjacent frequency bands (slots). The frequency band is the same size in each sector. In general, the total frequency band does not have to be the same in each sector, the frequency bands (slots) may be relatively prime, and may not be the same in each sector. In some embodiments, the BS 208,210,212 transmits a beacon signal, such as a high power broadcast signal. In some embodiments, beacon signal transmission in each sector may occur in three frequency ranges (bands) that alternate over time when scheduled. In another embodiment, the base station transmits a plurality of beacons signals in two or more of the plurality of carrier frequency bandwidth ranges (bands), and the plurality of beas are simultaneously transmitted from the sector transmitter in the plurality of frequency bands. ..
FIG. 3 shows three graphs 302, 304, 306 showing typical base station sector transmit signaling for frequency. This representative signaling may be transmitted in either the representative cell 100 shown in FIG. 1 or the representative cell (202,204,206) shown in FIG.
Graph 302 above FIG. 3 shows signaling from the base station sector 1 transmitter. Graph 302 is a complex of signals that can be transmitted at different times, for example at different symbol transmission periods. Transport frequency f<sub>1</sub>The first frequency band 310 centered on is used to send signals and information to the wireless terminal device in sector 1 as indicated by the label 319 of ordinary signaling. Periodically, for example, when not transmitting data such as an ordinary signal, the transmitter in sector 1 transmits the beacon signal S1F1 (sector 1 carrier frequency 1) 320 in the first frequency band. This frequency may be offset by a certain offset from the first carrier frequency and may be used by the wireless terminal device to identify and synchronize the carrier frequency used in the first sector. Carrier f<sub>2</sub>Periodically, the first sector transmitter sends the second carrier frequency f to provide information to the WT in the neighboring sector where is used.<sub>2</sub>The beacon signal S1F2 322 is transmitted at a predetermined frequency within the second frequency band 312 corresponding to. This signal is carried by WTs in adjacent sectors so that these terminals carry their receiver frequency f.<sub>2</sub>Can be detected without the need to adjust from band 312 associated with to other bands, such as the first frequency band 310 used in sector 1. In addition, carrier f<sub>3</sub>Periodically, the 1st sector transmitter sends the 3rd carrier frequency f to provide information to the WTs in the neighboring sectors where is used.<sub>3</sub>The beacon signal S1F3 324 is transmitted at a predetermined frequency within the third frequency band 314 corresponding to. This signal is due to the WT in adjacent sectors in which the third frequency band is used so that these terminal devices use their receiver frequency from the third frequency band 314, eg, in sector 1. It can be detected without the need to adjust to another band, such as band 310.
Graph 304 in the center of FIG. 3 shows signaling from the base station sector 2 transmitter. The graph 304 is a complex of signals that can be transmitted at various times, such as at various symbol transmission periods. Carrier frequency f to transmit signals and information to wireless terminals in sector 2 as indicated by the usual signaling 331 label.<sub>2</sub>The second frequency band 312 centered on is used. Periodically, for example, when not transmitting data such as a normal signal, the transmitter in sector 2 transmits the beacon signal S2F2 (sector 2 carrier frequency 2) 332 in the second frequency band 312. This frequency may be offset by a certain offset from the second carrier frequency and is used by the wireless terminal device in sector 2 to identify and synchronize the carrier frequency used in that second sector. obtain. Carrier f<sub>1</sub>Periodically, the second sector transmitter sends the first carrier frequency f to provide information to the WT in the neighboring sector where is used.<sub>1</sub>The beacon signal S2F1 330 is transmitted at a predetermined frequency within the first frequency band 310 corresponding to. This signal is tuned by WTs in adjacent sectors that use the first carrier frequency to other bands such as the second frequency band 312 used by these terminals for their receiver frequency in sector 2. It can be detected without the need for it. In addition, carrier f<sub>3</sub>Periodically, the second sector transmitter sends the third carrier frequency f to provide information to the WTs in the neighboring sectors where is used.<sub>3</sub>The beacon signal S2F3 334 is transmitted at a predetermined frequency of the third frequency band 314 corresponding to. This signal is transmitted by WTs in adjacent sectors where the third frequency band is used so that these terminal devices use their receiver frequency in other bands, such as the second frequency band 312, which is used in sector 2. Can be detected without the need to adjust to.
Graph 306 below FIG. 3 shows signaling from the base station sector 3 transmitter. Graph 306 is a complex of signals that can be transmitted at different times, for example at different symbol transmission periods. In order to transmit signals and information to wireless terminals in sector 3 as indicated by the usual signaling 343 label, the carrier frequency f<sub>3</sub>The third frequency band 314 centered on is used. Periodically, for example, when not transmitting data such as an ordinary signal, the transmitter in sector 3 transmits the beacon signal S3F3 (sector 3 carrier frequency 3) 344 in the third frequency band. The frequency of this beacon signal may be offset by a certain offset from the third carrier frequency, and the wireless terminal device in sector 3 is used to identify and synchronize the carrier frequency used in the third sector. Can be used by. Carrier f<sub>1</sub>Periodically, the third sector transmitter sends the first carrier frequency f to provide information to the WT in the neighboring sector where is used.<sub>1</sub>The beacon signal S3F1 340 is transmitted at a predetermined frequency within the first frequency band 310 corresponding to. This signal is tuned by WTs in adjacent sectors that use the first carrier frequency to other bands such as the third frequency band 314 used by these terminals for their receiver frequency. It can be detected without the need for it. In addition, carrier f<sub>2</sub>Periodically, the third sector transmitter sends the second carrier frequency f to provide information to the WT in the neighboring sector where is being used.<sub>2</sub>The beacon signal S3F2 342 is transmitted at a predetermined frequency of the second frequency band 312 corresponding to. This signal is transmitted by WTs in adjacent sectors where the second frequency band is used so that these terminal devices use their receiver frequency in other bands, such as the third frequency band 314, which is used in sector 3. Can be detected without the need to adjust to.
Each beacon signal can uniquely identify the carrier wave associated with the sector that emitted the beacon signal. The nine representative beacon signals shown in FIG. 3 have different frequencies. Therefore, it is possible to match the frequency of the detected beacon signal with a frequency belonging to a set of known beacon frequencies to determine which sector transmitter was the source of the detected beacon signal.
According to the present invention, a wireless terminal device such as a mobile node can receive a beacon signal from its own base station sector transmitter and another, for example, an adjacent base station sector transmitter. The beacon signal is received within the same frequency band that the wireless terminal device is currently using for normal signaling and / or control signaling, such as data, so that the WT does not have to switch frequency bands. The WT measures the beacon signal strength, such as power. These measurements are made in addition to frequency measurements, such as tones. Comparison of the strength of different beacon signals received from different base station sector transmitters determines when to hand off to the carrier frequency used by the adjacent sector and to the wireless terminal equipment within that adjacent sector. Used to provide information. Beacon signal comparisons also indicate which carrier frequency the wireless terminal device should use for normal signaling after handoff. In some embodiments, this carrier frequency is determined to be the carrier frequency for normal signaling used by the base station sector transmitter that transmitted the stronger of the received plurality of beacon signals.
For example, the carrier frequency f is operating in sector 1 and therefore for normal signaling such as receiving information from a base station.<sub>1</sub>Consider the wireless terminal device 104 shown in FIG. 1, which uses and its associated bandwidth 310. But it also has a carrier frequency f<sub>1</sub>The beacon signal in the frequency band 310 corresponding to is also monitored. Referencing the left part of Figure 3, carrier f<sub>1</sub>The signaling transmitted by the BS in each of the three sectors in the first frequency band 310 corresponding to is shown. The wireless terminal device 104 compares the received intensity of the beacon signal 320 from sector 1 with the received intensity of the beacon signals 330 and 340 of the adjacent sectors detected within the first frequency band 310. When the wireless terminal device approaches the boundary separating the sector 1 and the sector 2, the reception strength of the beacon signal S2F1 330 in the first frequency band transmitted by the BS sector 2 is received from the sector 1 beacon signal S1F1 320. It becomes stronger relative to the signal strength to be generated. At some point, based on this comparison of the received beacon signal strength and the criteria within the radio terminal, the radio terminal is the carrier frequency, which is the frequency used for normal signaling in sector 2. f<sub>2</sub>Start a handoff to. The wireless terminal device has a carrier frequency f based on a known predetermined understanding between the base station and the wireless terminal device, for example, based on the beacon tone position in the frequency domain of the stronger received beacon signal.<sub>3</sub>Not the carrier frequency f<sub>2</sub>Know that it will switch to.
Signaling from each sector of the same cell can be timed out of sync with each other. In some embodiments, there is a constant time offset between the transmission of beacon signals by multiple adjacent sector transmitters of the same cell to a given carrier band. In some embodiments, there is a constant time offset between the transmission of the beacon signal to different carrier bands by one given sector transmitter.
The same or similar method of the invention described for handoffs at sector boundaries is also used for handoffs at cell boundaries, such as in the case of wireless terminal device 232 of FIG. 2 located at cell boundaries. In such cases, the handoff is done from one cell sector to another cell sector. With respect to the cell, the position of the beacon can also be used to convey cell information such as a cell identifier such as a slope identifier. Different cells can use different predetermined frequencies for the beacon signal. The change in the beacon signal and / or the tone position of the beacon signal over time can be used to convey cell identification information such as slope information and / or sector identification information such as sector type. In one embodiment, the change in the beacon signal is a change in beacon position via a hopping pattern on the tone. Here the tone can indicate the slope used as the cell identifier corresponding to one cell.
FIG. 4 shows an example in which two different adjacent cells have a slight change in beacon frequency positioning in the same sector or representative sector 1 to provide a beacon signal identifier for sector and cell levels. For example, FIG. 402 can correspond to a signal transmitted from BS1 208 sector 1 214 of the cell 1 202 transmitter of FIG. 2, and FIG. 404 is transmitted from BS2 210 sector 1 220 of the cell 2 204 transmitter of FIG. It can correspond to the signal. FIG. 402 shows the carrier frequency f.<sub>1</sub>Bandwidth 406 associated with and carrier frequency f<sub>2</sub>Bandwidth 408 associated with and carrier frequency f<sub>3</sub>Includes and associated bandwidth 410. Carrier f<sub>1</sub>Within the bandwidth 406 for, the BS1 sector 1 transmitter transmits the beacon signal 412 and the usual signaling 414 such as user data and control signals. Carrier f<sub>2</sub>Within the bandwidth 408 for, the BS1 sector 1 transmitter transmits the beacon signal 416. Carrier f<sub>3</sub>Within the bandwidth 410 for, the BS1 sector 1 transmitter transmits the beacon signal 418. The various signals 412,414,416, and 418 may be transmitted at different times, for example the ordinary signaling 414 is transmitted most of the time, and the beacon signal of the set of beacon signals containing 412,416,418 is occasionally predetermined instead of the ordinary signaling 414. It is sent periodically in the order of. Ordinary signaling 414 includes user data, including at least one of voice, text, and user application data. Beacon signals 412, 416, and 418 convey transmitter information, but not information for a specific user. FIG. 404 shows the carrier frequency f.<sub>1</sub>Bandwidth 406 and carrier frequency f related to<sub>2</sub>Bandwidth 408 associated with and carrier frequency f<sub>3</sub>Includes bandwidth 410 and associated with. Carrier f<sub>1</sub>Within the bandwidth 406 for, the BS2 sector 1 transmitter transmits the beacon signal 420 and the usual signaling 422, such as user data and control signals. Carrier f<sub>2</sub>Within the bandwidth 408 for, the BS2 sector 1 transmitter transmits the beacon signal 424. Carrier f<sub>3</sub>Within the bandwidth 410 for, the BS2 sector 1 transmitter transmits the beacon signal 426. The various signals 420,422,424, and 426 may be transmitted at different times, for example the normal signaling 422 is transmitted most of the time, and the beacon signals in the set of beacon signals containing 420,424,426 occasionally replace the normal signaling 422. It is sent periodically in a predetermined order. Since the beacon signals 412 and 420 in the same band 406 are at different frequency positions, the wireless terminal device that receives the beacon signal can distinguish the two cells. Since the beacon signals 416 and 424 in the same band 408 are at different frequency positions, the wireless terminal device receiving the beacon signal can distinguish the two cells. Since the beacon signals 418 and 426 in the same band 410 are at different frequency positions, the wireless terminal device that receives the beacon signal can distinguish the two cells.
The two cells do not have to be time-synchronized with each other and are generally not time-synchronized. Therefore, in the cell-to-cell handoff operation, the wireless terminal equipment probably needs to perform a timing synchronization operation, for example, they receive in the air from a new cell before transmitting user data such as text or voice data. The symbol transmission timing is adjusted based on one or more of the signals. According to the present invention, beacon signals or other broadcast signals can be used to achieve coarse timing synchronization and to achieve minimization of pauses during handoff operation.
FIG. 5 shows FIG. 500 of representative signaling from two base station sector transmitters, for example, adjacent base station sector transmitters of the same cell base station, according to the method of the invention. FIG. 502 shows the carrier wave f on the vertical axis 514 with respect to the time on the horizontal axis 516.<sub>1</sub>A plot of base station sector 1 transmitter signaling to the frequency band. FIG. 504 shows the carrier wave f on the vertical axis 518 with respect to the time on the horizontal axis 520.<sub>2</sub>A plot of base station sector 1 transmitter signaling to the frequency band. FIG. 506 shows the carrier wave f on the vertical axis 522 with respect to the time on the horizontal axis 524.<sub>3</sub>A plot of base station sector 1 transmitter signaling to the frequency band. FIG. 508 shows the carrier wave f on the vertical axis 526 with respect to the time on the horizontal axis 528.<sub>1</sub>It is a plot of base station sector 2 transmitter signaling to the frequency band. FIG. 510 shows the carrier wave f on the vertical axis 530 with respect to the time on the horizontal axis 532.<sub>2</sub>It is a plot of base station sector 2 transmitter signaling to the frequency band. FIG. 512 shows the carrier wave f on the vertical axis 534 with respect to the time on the horizontal axis 536.<sub>3</sub>It is a plot of base station sector 2 transmitter signaling to the frequency band. In a typical signaling plot (502,504,506,508,510,512), the time axis (516,520,524,528,532,536) is the same. In a typical plot (502,504,506,508,510,512), ordinary signaling containing user data is represented by a wide and low height rectangle, and beacon signaling containing transmitter information but not specific user data is narrow. It is represented by a tall rectangle. User data includes at least one of voice, text, and user application data. A beacon signal is a signal that concentrates at least 60% of the power of a sector transmitter on tones that occupy less than one-fifth of the frequency band.
Sector 1 base station transmitter f f beacon signal 538<sub>1</sub>Ordinary signaling 540 in the frequency band f<sub>1</sub>Beacon signal 542 in the frequency band<sub>2</sub>Ordinary signaling 544 in the frequency band f<sub>1</sub>Beacon signal 546 in the frequency band<sub>3</sub>Ordinary signaling 548 in the frequency band f<sub>1</sub>It is transmitted in order to the frequency band. The sequence of transmission signaling types and bands corresponding to the signaling set (538,540,542,544,546,548) is as shown by the signaling set (538', 540', 542', 544', 546', 548'). Is repeated by the signaling set (538 , 540, 542 , 544, 546 , 548).
Sector 2 base station transmitters usually signal 547 f<sub>2</sub>Beacon signal 548 in the frequency band<sub>1</sub>Ordinary signaling 550 in the frequency band f<sub>2</sub>Beacon signal 552 in the frequency band<sub>2</sub>Ordinary signaling 554 in the frequency band f<sub>2</sub>Beacon signal 556 in the frequency band<sub>3</sub>Ordinary signaling 558 in the frequency band f<sub>2</sub>It is transmitted in order to the frequency band. This sequence of signaling types and bands of transmission corresponding to a set of signaling (548,550,552,554,556,558) is provided by the set of signaling (548', 550', 552', 554', 556', 558') as illustrated. It is then repeated by the signaling set (548 ", 550", 552 ", 554", 556 ", 558").
The first and second base station transmitters are in the same cell, f<sub>2</sub>Beacon signal transmission of the first sector base station transmitter to the band and f<sub>1</sub>There is a certain timing offset from the beacon signal transmission of the second sector base station transmitter to the frequency band. The timing relationship between the beacon signals 548 and 542 is shown as the interval 560 and the timing relationship between the beacon signals 542 and 548'is shown as the interval 562. In some embodiments, timing synchronization between multiple sector transmitters in the same cell is such that the beacon signals are transmitted simultaneously by different sector transmitters.
Time intervals that include multiple interval complexes corresponding to signaling 538, 540, 544, and 548 are set by the first sector base station transmitter in the first frequency band or f.<sub>1</sub>Sends to the band but the second frequency band, i.e. f<sub>2</sub>This is the first period in which the band is operated so as not to transmit. The time interval corresponding to the beacon signal 542 is set by the first sector base station transmitter in the second frequency band, that is, f.<sub>2</sub>Manipulated to transmit within the band, the 1st sector base station transmitter is in the 1st frequency band or f<sub>1</sub>This is the second period in which transmission is not performed within the band. The second period is at least less than one-fifth of the first period. In some embodiments, the second period is less than 1/20 of the first period. These operations are as shown in f<sub>1</sub>Bandwidth signaling 538', 540', 544' and 548', and f<sub>2</sub>Bandwidth signaling 542'repeated.
Time intervals that include a complex of intervals corresponding to signaling 550,552,554, and 558 are such that the second sector base station transmitter is in the second frequency band or f<sub>2</sub>Send to band but first frequency band i.e. f<sub>1</sub>It is the third period that is operated so as not to transmit in the band. The time interval corresponding to the beacon signal 548 is set by the second sector base station transmitter in the first frequency band, that is, f.<sub>1</sub>Manipulated to transmit within the band, the second sector base station transmitter is in the second frequency band or f<sub>2</sub>This is the fourth period in which transmission is not performed within the band. The fourth period is at least less than one-fifth of the third period. In some embodiments, the fourth period is less than 1/20 of the third period. These operations are as shown in f<sub>2</sub>Bandwidth signaling 550', 552', 554' and 558, and f<sub>1</sub>Bandwidth signaling 548'is repeated.
If the two base station transmitters were transmitters in multiple cells adjacent to each other, the signaling would be similar, but the timing between the two transmitters would not necessarily be synchronized.
FIG. 6 shows a representative communication system 600 realized by the present invention utilizing the method of the present invention. The representative system includes a plurality of cells (cell 1 602, cell M 604). Each cell represents a radio coverage area of an access node, such as a base station. Cell 1 602 corresponds to base station 1 606 and cell M 604 corresponds to base station M 608. Each cell is divided into a plurality of sectors. Although this representative system demonstrates a three-sector embodiment, according to the present invention, cells with less than or more sectors are also possible. The representative system uses different carrier frequencies in each sector of a cell. In other embodiments, frequencies can be reused by multiple sectors within a cell, for example by reused by non-adjacent sectors. Sector 1 is the carrier frequency f<sub>1</sub>Sector 2 is the carrier frequency f<sub>2</sub>Using; sector 3 is the carrier frequency f<sub>3</sub>To use. The same carrier frequency is used by the same sector in other cells of the representative system. In some embodiments, the carrier frequencies used in the various cells of the system may be slightly different. In yet other embodiments, the carrier frequencies used in the separate cells may be significantly different. Cell 1 602 contains sector 1 610, sector 2 612, and sector 3 614. Cell M 604 includes sector 1 616, sector 2 618, and sector 3 620. A typical boundary region 622 is shown in which cell 1 sector 1 610 overlaps cell M sector 2 618, where handoff operations can be performed according to the method according to the invention. According to the method of the present invention, the handoff operation can also be performed in the boundary region between different sectors of the same cell.
The representative system of FIG. 6 also includes a plurality of end nodes EN 1 and EN N such as a wireless terminal device such as a mobile node in each sector of each cell. The wireless terminal device is coupled to the base station via a wireless link. If the end nodes are mobile devices, they can move within the sectors and cells of the system. According to the method of the present invention, the end node can receive and process signals from a plurality of base station sector transmitters, such as a beacon signal, within the same carrier band. According to the method of the present invention, the end node obtains information obtained from a plurality of base station sector transmitters in the process of starting and executing a handoff operation from one base station sector connection point to another base station sector connection point. Can be used. Mobile devices are sometimes referred to as mobile communication devices or mobile nodes. Cell 1 602 sector 1 610 contains multiple ENs (EN 1 624, EN N 626), cell 1 602 sector 2 612 contains multiple ENs (EN 1 628, EN N 630), and cell 1 602 sector 3 614 contains multiple ENs. EN (EN1 632, including EN N 634). Cell M 604 sector 1 616 contains multiple ENs (EN 1 636, EN N 638), cell M 604 sector 2 618 contains multiple ENs (EN 1 640, EN N 642), and cell 1 604 sector 3 620 contains multiple ENs. Includes EN (EN 1 644, EN N 646).
Each access node (base station) (606,608) is coupled to a network node 648, such as a router, via a network link (650,652). Network node 648 is coupled to other network nodes and the Internet via network link 654. The network link (650,652,654) may be, for example, an optical fiber cable.
The sector boundary area is identified as a dividing line within each cell that separates the three sectors (610,612,614) or (616,618,620), and the cell boundary area (622) is shown as an overlapping area between cell 1 and cell M. .. As the radio terminal moves within the system to approach and / or cross sector and / or cell boundaries, handoff operations, including changes in carrier frequency, may be performed in accordance with the present invention.
According to the present invention, the base station (606,608) has (3 carrier frequencies f).<sub>1</sub>, F<sub>2</sub>, F<sub>3</sub>Beacon signals within each of the three frequency bands (related to) are periodically transmitted within each sector of each cell. According to the present invention, end nodes (624,626,628,630,632,634,636,638,640,642,644,646) monitor beacon signals within the frequency band of current operation to make inter-sector and / or inter-cell handoff decisions.
FIG. 7 shows a typical access node (base station) 700 realized according to the present invention. The base station 700 of FIG. 7 can be a detailed representation of any of the base stations of the system of FIGS. 6, 1 or 2. The base station 700 includes a processor 702 such as a CPU, and a plurality of receivers (sector 1 receiver 704, sector 2 receiver 706, ..., Sector N receiver 708), one for each sector of the base station 700, for example. Multiple transmitters (sector 1 transmitter 710, sector 2 transmitter 712, ..., sector N transmitter 714), one for each sector of the base station, I / O interface 716, clock module 718, memory 720 including. For example, one beacon transmitter circuit for each sector of the base station (beacon sector 1 transmitter 7102', beacon sector 2 transmitter 712', ... beacon sector N transmitter 714') has a beacon signal and normal control / user data. It may be included as part of a sector transmitter in embodiments where separate circuits are used to generate the signal. Each base station sector receiver (704,706,708) is coupled to each sector antenna (sector 1 receiving antenna 730, sector 2 receiving antenna 732, sector N receiving antenna 734), for example, an uplink signal including a request for handoff, a timing control signal. , Power control signals, and signals such as user data can be received from wireless terminal devices within the covered sectors. Each sector transmitter (710,712,714) uses the beacon signal within the frequency band used for normal signaling in its own sector and for normal signaling by adjacent sector transmitters in the system. Transmit within the frequency band. Each receiver (704,706,708) has a decoder (736,738, Each includes 740), which decodes the encoded signal of the received uplink to extract the transmitted information. Each sector transmitter (710,712,714) is coupled to a sector antenna (sector 1 transmit antenna 742, sector 2 transmit antenna 744, sector N transmit antenna 746), respectively, and according to the present invention, a beacon signal including transmitter information, user data, and allocation. Signals including assignment signals, affirmative response signals and ordinary downlink signaling including pilot signals can be transmitted within the covered sector. Each sector transmitter (710,712,714) includes an encoder (748,750,752) to encode the downlink information before transmission. In some embodiments, base station 700 includes and uses separate receivers, transmitters, and / or antennas for each sector of the cell. In some embodiments, the base station is a single receiver having the ability to receive signals from each sector covered by the base station, transmitting within each sector covered by the base station. Use a single transmitter with sectored functionality and / or multiple sectored antennas, such as antennas with separate elements corresponding to different sectors. In some embodiments, sector beacon transmitter circuits (710,712,714) are included, each coupled to a transmitting antenna (742,744,746) in the corresponding sector. Sector beacon transmitters (710', 712', 714') are used to transmit some or all of the beacon signaling while user data is being transmitted, within one or more cells of multiple beacon signals. Allows transmission to, thus limiting the interruption of normal normal signaling transmission by offloading some or all of the beacon transmission functionality to beacon-related circuits. Each 714) is coupled to a sector antenna (sector 1 transmit antenna 742, sector 2 transmit antenna 744, sector N transmit antenna 746), and according to the present invention, a beacon signal including transmitter information, user data, and assignment signals. ), Signals including normal downlink signaling including affirmative response signals and pilot signals can be transmitted within the covered sector. Each sector transmitter (710,712,714) includes an encoder (748,750,752) to encode the downlink information before transmission. In some embodiments, base station 700 includes and uses separate receivers, transmitters, and / or antennas for each sector of the cell. In some embodiments, the base station is a single receiver having the ability to receive signals from each sector covered by the base station, transmitting within each sector covered by the base station. Use a single transmitter with sectored functionality and / or multiple sectored antennas, such as antennas with separate elements corresponding to different sectors. In some embodiments, sector beacon transmitter circuits (710,712,714) are included, each coupled to a transmitting antenna (742,744,746) in the corresponding sector. Sector beacon transmitters (710', 712', 714') are used to transmit some or all of the beacon signaling while user data is being transmitted, within one or more cells of multiple beacon signals. Allows transmission to, thus limiting the interruption of normal normal signaling transmission by offloading some or all of the beacon transmission functionality to beacon-related circuits. Each of the 714) is coupled to a sector antenna (sector 1 transmit antenna 742, sector 2 transmit antenna 744, sector N transmit antenna 746), and according to the present invention, a beacon signal including transmitter information, user data, and assignment signals (assignment signals). ), Signals including normal downlink signaling including affirmative response signals and pilot signals can be transmitted within the covered sector. Each sector transmitter (710,712,714) includes an encoder (748,750,752) to encode the downlink information before transmission. In some embodiments, base station 700 includes and uses separate receivers, transmitters, and / or antennas for each sector of the cell. In some embodiments, the base station is a single receiver having the ability to receive signals from each sector covered by the base station, transmitting within each sector covered by the base station. Use a single transmitter with sectored functionality and / or multiple sectored antennas, such as antennas with separate elements corresponding to different sectors. In some embodiments, sector beacon transmitter circuits (710,712,714) are included, each coupled to a transmitting antenna (742,744,746) in the corresponding sector. Sector beacon transmitters (710', 712', 714') are used to transmit some or all of the beacon signaling while user data is being transmitted, within one or more cells of multiple beacon signals. Allows transmission to, thus limiting the interruption of normal normal signaling transmission by offloading some or all of the beacon transmission functionality to beacon-related circuits. It is combined with 746) respectively. Sector beacon transmitters (710', 712', 714') are used to transmit some or all of the beacon signaling while user data is being transmitted, within one or more cells of multiple beacon signals. Allows transmission to, thus limiting the interruption of normal normal signaling transmission by offloading some or all of the beacon transmission functionality to beacon-related circuits.
Base station I / O interface 716 couples base station 700 to other network nodes such as other access nodes (base stations), routers, AAA servers, home agent nodes and the Internet. The I / O interface 716 allows a WT that uses the BS700 as a network connection point to communicate with other WTs that use another BS as their network connection point, such as peer nodes.
Clock module 718 is used to maintain timing synchronization between the various sectors covered by the base station. Synchronization between different sectors of the same cell allows multiple beacon signals to be transmitted from different base station sector transmitters with a constant timing offset between the beacon signals. Synchronization between different sectors of the same cell is also more efficient because the WT involved in the handoff can, in some embodiments, omit certain timing synchronization operations that would otherwise be required. Provides intra-sector inter-sector handoff operation.
Memory 720 contains routine 754 and data / information 756. Processor 702 executes routine 754 and also includes standard functions such as scheduling, base station power control, base station timing control, communication, and normal signaling, as well as new features of the invention including beacon signaling and handoff operation. Use the data / information 756 in memory 720 to control the operation of the including base station 700.
The data / information 756 in the memory 720 contains a plurality of sets of data / information, such as a set for each sector covered by the base station (sector 1 data / information set 776, sector N data / information set 782). Including. The sector 1 data / information set 776 includes data 784, sector information 786, beacon information 788, and wireless terminal device (WT) data / information 790. The data 784 includes user data transmitted to and received from the wireless terminal device. The sector information 786 includes carrier wave information 796 and frequency band information 798. Carrier information 786 includes carrier frequencies associated with sector 1 and adjacent sectors within the system. The frequency band information 786 includes bandwidth information corresponding to the carrier wave information 786. The sector information 786 specifies a carrier wave and a band related to ordinary signaling in the sector 1, and a carrier wave and a band for transmitting a beacon signal without transmitting data for a specific user.
Beacon information 788 includes tone information 701, timing information 703, tone hopping information 705, power information 707, and transmitter information 709. The tone information 701 includes information that associates the beacon signal from the sector 1 transmitter with a particular frequency or tone. The timing information 703 is, for example, sector 1 transmitter 710 f.<sub>1</sub>Sector 1 transmitter 710 f when it should send a beacon signal to the carrier band<sub>2</sub>When to send a beacon signal to the carrier band, and sector 1 transmitter 710 f<sub>3</sub>It includes information for specifying the beacon signal transmission timing such as when the beacon signal should be transmitted to the carrier band. The timing information 703 is the timing relationship and order between the plurality of beacon signals transmitted by the sector 1 transmitter 710, and the beacon signals transmitted by a plurality of adjacent sector transmitters such as the sector 1 transmitter 710 and the sector 2 transmitter 712. It also includes information that identifies the timing relationship between a plurality of beacon signals, such as the timing relationship of the above. The tone hopping information 705, such as the information used to generate the hopping sequence, is such that the beacon tone or set of multiple tones corresponding to a sector 1 transmitter within a particular frequency band changes as a function of time. Used for beacon signals, such as when obtaining. Power information 707 includes transmit power level information for each of the beacon signals transmitted by the sector 1 transmitter. In some embodiments, the base station sector transmitter concentrates at least 60% of its sector transmission power on the tone of the beacon signal. Transmitter information 709 includes information transmitted by the beacon signal that associates the beacon signal with a particular base station sector transmitter, such as a base station sector transmitter identifier.
The WT data / information 790 includes a plurality of WT data / information sets for each WT, namely WT1 data / information 792, WTN data / information 794. The WT1 data / information 790 includes user data 711, terminal device ID information 713, sector ID information 715, mode information 717, dedicated resource information 719, and handoff message 721. User data 711, such as data from / to the peer node of WT1 in a communication session with WT1, includes voice data 723, text data 725, and / or user application data 727. The terminal device ID information 713 includes information that associates the WT with a base station, such as a sector 1 base station allocation identifier. The sector ID information 715 identifies the sector to which the WT1 is currently attached and to a particular carrier frequency commonly used for signaling by the sector transmitter at that identified connection point, for example a sector 1 transmitter. Contains information that associates WT1. The sector ID information 715 also includes information that identifies the sector requested by WT1 as a new connection point in the handoff request. The mode information 717 includes information that identifies the operating state of the WT1, such as ON, Hold, Sleep, and Access. Dedicated resource information 690, such as the downlink segment and the uplink segment, includes the traffic channel segment assigned to WT1 by the scheduler module 766. The handoff message 721 includes information related to the handoff operation, such as a handoff request message from the WT1 in response to a beacon signal received, measured and compared from multiple base station sector transmitters.
Routine 754 includes a plurality of sets of routines, for example for each sector covered by the base station (sector 1 routine 758, ..., Sector N routine 760). Routine 758 includes communication routine 762 and base station control routine 764. Communication routine 762 executes various communication protocols used by the base station. According to the present invention, the base station control routine 764 uses data / information 756 to receive receiver 704, transmitter 710, optional beacon transmitter 722, I / O interface 716, scheduling, ordinary control and data signaling, beacon signaling, And control base station sector 1 operations, including handoff operations. The base station control routine 764 includes a scheduler module 766 and a signaling routine 768. The signaling routine 768 includes a beacon routine 770, a normal signaling routine 772, and a handoff routine 774. A scheduler module 659, such as a scheduler, schedules airlink resources, such as temporal bandwidth in the form of segments, to multiple wireless terminal devices for uplink and downlink communications, for example.
The signaling routine 768 controls receiver, decoder, transmitter, encoder, normal signal generation, beacon signal generation, data and control tone hopping, signal transmission, signal reception, and handoff signaling. The beacon routine 770 controls the generation and transmission of beacon signals using data / information 756 including beacon information, such as sector 1 beacon information 788, according to the present invention. According to the present invention, the beacon signal is transmitted by each sector transmitter in each of the carrier frequency bands identified as being used for normal signaling by that sector or used for normal signaling by adjacent sectors in the system. Can be done. According to one embodiment of the present invention, when a beacon signal is transmitted by a sector transmitter to a frequency band other than the frequency band it uses for normal signaling, the normal signaling by the base station sector transmitter is , Suspended for the period corresponding to the beacon signal.
In some embodiments, the beacon signal from sector 1 of base station 700 is transmitted through sector transmitter 710. In another embodiment, some or all of the beacon signal from sector 1 of the BS 700 may be transmitted by the beacon transmitter 722.
Ordinary signaling routine 772 controls the operation of ordinary downlink signaling and uplink signaling. Normally downlink signaling includes pilot signals, assignment signals, acknowledgment signals, other control signals, and downlink traffic channel signals. The downlink traffic channel signal includes a signal for a specific user, for example, a signal for transmitting user data 711 to a specific WT.
The handoff routine 774 controls handoff signaling transmitted from base station 700 sector 1 and received by base station 700 sector 1, such as handoff message 721.
Routine 758 and data / information 756 are shown sector by sector in FIG. 7, but in certain embodiments, features, routines, modules, and / or information can be shared between multiple sectors. For example, communication routines and functions related to the operation of the I / O interface 702 may be common and shared between the sectors.
FIG. 8 shows a typical wireless terminal device (end node) 800 such as a mobile node realized according to the present invention. The wireless terminal device 800 of FIG. 8 can be a more detailed representation of the end node of either of the systems of FIGS. 6, 1 or 2. A typical wireless terminal device 800 includes a receiver 802, a transmitter 804, a processor 806 such as a CPU, a user I / O device 808, and a memory 810, which are coupled to each other via bus 812 and through which they are coupled. These various elements can exchange data and information. A receiver 802, including a decoder 814, is coupled to an antenna 816 through which the wireless terminal device 800 performs signaling, including beacon signaling transmitted from multiple base station sector transmitters within the same carrier band in accordance with the present invention. Can be received. In a typical WT800, the receiver 802 can be tuned to one carrier band at a time. Decoder 814 in receiver 802 can decode ordinary signaling and can also use an error correction coding process to recover information that has been overwritten or interfered with by beacon signaling. Transmitter 804 is coupled to antenna 820 and can send signaling and information to the base station, including a request to initiate a handoff to another sector using a different carrier frequency. A user I / O device 808, such as a keyboard, keypad, mouse, microphone, display and / or speaker, allows a user of the WT800 to enter user data directed to a peer node and also emit and receive from the peer node. Output the user data. Memory 810 of the wireless terminal device includes routine 822 and data / information 824. Processor 806 uses data / information 824 in memory 810 to execute routine 822 and to control the operation of wireless terminal equipment 800, including the execution of beacon-related functions of the present invention.
The wireless terminal device data / information 824 includes user data 826 such as data information and files intended to be exchanged with the peer node during a communication session with the wireless terminal device 800. User data 826 includes voice, text, and / or user application data received as part of normal downlink signaling in the downlink traffic channel segment. User information 828 includes terminal device ID information 832, base station ID information 834, sector ID information 836, mode information 838, identified beacon information 840, resource information 842, and handoff information 844. The terminal device ID information 832 may be an identifier that identifies the wireless terminal device 800 with respect to the base station sector, which is assigned to the WT 800 by the base station sector to which the WT is attached. The base station ID information 834 can be, for example, a slope value associated with the base station and used in a hopping sequence that identifies the base station among a plurality of base stations in the communication system. The sector ID information 836 includes information that identifies the sector ID of the transmitter / receiver of the sectorized base station through which ordinary signaling is transmitted, and corresponds to the sector of the cell in which the wireless terminal device 800 is located. The mode information 838 identifies the current state of the wireless terminal device 800, for example on / hold / sleep / access. The identified beacon information 840 is received, for example, cell / sector ID, signal strength level, filtered signal strength level, and carrier frequency associated with normal signaling in the sector from which the beacon signal was transmitted. Information about each measured beacon signal can be included. The identified beacon information 840 was derived from information comparing adjacent sector beacons with current WT sector beacons, information comparing measured beacons signals with each other, and / or beacon signals measured against handoff criteria. Information can be included. Resource information 842 is the user Contains information that identifies the segment assigned to the WT800, including the downlink traffic channel segment, used to convey a normal signal containing data 826 from the base station sector transmitter to a particular WT800. The handoff information 844 includes, for example, a request information message from the WT800 requesting that the handoff be initiated based on a comparison of the beacon signals received from the plurality of base station sector transmitters.
The wireless terminal system information 832 includes timing information 846, beacon ID information 848, handoff reference information 850, and cell / sector ID information 852. Timing information 846 includes (i) OFDM symbol transmission intervals, (ii) grouping of OFDM symbol intervals such as slots, super slots, beacon slots, and ultra slots, intervals between beacon signals, and (iii) beacon signals for normal signaling. Includes OFDM transmission timing information, including information that defines transmission timing and / or (iv) a fixed timing relationship between beacon signals from different sector transmitters in the same cell. Beacon ID information 848 associates a beacon of a particular sector / cell in the communication system with a particular frequency within a particular carrier band, allowing the WT800 to identify the source base station sector transmitter of each received beacon signal. Can include information such as lookup tables, equations, etc. The handoff reference 850 is adjacent, for example, the minimum threshold for the intensity level of the beacon signal from the adjacent sector and / or the threshold level for the comparative intensity of the adjacent sector receive beacon signal for the sector receive beacon signal strength of the WT itself. It can include a threshold limit used by the wireless terminal device 800 to trigger a handoff request to a sector / cell. The cell / sector ID information 852 can include data, information, control signals, and information used to construct hopping sequences used for processing, transmitting and receiving beacon signals. Cell sector ID information 852 includes carrier information 854 that includes information that associates each sector / cell of a base station in the communication system with a particular set of carrier frequencies, bandwidths, and tones.
Routine 822 includes communication routine 856 and wireless terminal device control routine 858. The radio terminal device control routine 858 includes a signaling routine 860. The signaling routine 860 includes a beacon routine 862 and a normal signaling module 864.
The wireless terminal device communication routine 856 executes various communication protocols used by the wireless terminal device 800. The wireless terminal device control routine 858 executes basic control functions of the wireless terminal device 800, including power control, timing control, signaling control, data processing, I / O, and control of the beacon-related functions of the present invention. The signaling routine 860 uses the data / information 824 in memory 810 to control the operation of receiver 802 and transmitter 804. The Beacon Routine 862 includes a Beacon Processing and Identification (ID) Module 866, a Beacon Strength Measurement Module 868, a Beacon Signal Comparison Module 870, and a Handoff Module 872. Beacon processing and ID module 866 uses system information 832, including beacon ID information 848 and cell / sector ID information 852, to identify the received beacon signal and transfer that information to the user's identified beacon information 840. Store. The beacon signal strength measuring module 868 measures the signal strength of the received beacon signal and stores the information in the user-specified beacon information 840. The Beacon Comparison Module 870 compares the identified beacon information to determine when to initiate a handoff to an adjacent sector / cell. The Beacon Comparison Module 870 can compare individual Beacon signal strength levels with the lowest threshold level within the handoff reference 850. The beacon comparison module can compare the relative signal strength levels of the WT's own current sector connection point beacon signal with the adjacent sector / cell beacon signal. The Beacon Comparison Module can compare relative intensity level difference measurements to threshold levels within the handoff reference 850.
The handoff module 872 can generate signaling to initiate a sector-to-sector and / or cell-to-cell handoff when triggered by output from the Beacon Comparison Module 870. The new carrier frequency to be used after the handoff has been pre-specified according to the present invention.
In some embodiments, the base station is unable to transmit beacon signals corresponding to each of the system frequency bands within a given sector. In some embodiments, the base station limits the beacon signal transmitted within a given sector to a subset corresponding to the frequency band normally used for signaling by its own sector and adjacent sectors. Can be done. In some embodiments, the base station can limit the beacon signals transmitted within a given sector to a subset corresponding to the frequency band normally used for signaling in adjacent sectors.
Although a typical communication system whose bandwidth is divided into three carrier slots (frequency bands) is shown, the present invention is another communication system in which the same frequency band is not used everywhere in the system. Can be applied to.
In certain embodiments, the various features of the elements of the invention are realized in one part of the communication system and may not be realized in other parts of the system. In such an embodiment, the wireless terminal device implemented in accordance with the present invention utilizes the features and methods of beacon signaling of the present invention, if available, when making decisions regarding inter-sector and / or inter-cell handoffs. In other cases, known handoff techniques can be used.
FIG. 9 is a flowchart 900 of a typical method of operating a base station transmitter in a wireless communication system that transmits signals to various frequency bands according to the present invention. The operation begins at step 902, where the base station transmitter is powered and initialized. The operation proceeds from step 902 to step 904 and step 908 at the same time. In step 904, the first base station transmitter is operated to transmit user data, including, for example, voice, text and / or images, within the first frequency band during the first period. During this first period, the first base station transmitter does not transmit within the second frequency band. The operation proceeds from step 904 to step 906. In step 906, the first base station transmitter is operated to transmit, for example, a beacon signal within the second frequency band in the second period, the second period being shorter than the first period, eg, the first period. 1 / N of, where N is a positive value greater than 2, for example 3,5,10,20,100 or any other value depending on the particular embodiment. In some embodiments, the second period is at least one-fifth of the first period. In other embodiments, the second period is shorter than one tenth of the first period, and in yet other embodiments, the second period is shorter than one-hundredth of the first period. In some embodiments, the first and second frequency bands are of the same size. As a result of the relationship between the first and second periods, the first transmitter is within the first frequency band more than the second frequency band, eg, 20x, 50x, 100x, or more. ,Send. In some embodiments, the first base station transmits, for example, user data or other signals within the first frequency band over the entire or part of the second period. This is done in optional step 907 when executed. The operation returns from step 906 or 907 to step 904, depending on the embodiment, step 904, The sequence of 906 and 907 is repeated, eg steps 904 and 906 are performed at regular intervals. In one embodiment, in step 906, the first transmitter transmits 60% of the transmit power in one or more tones that occupy less than one-fifth of the second frequency band. In the same or other embodiment, in step 906, the first base station transmitter delivers one tone to the second frequency at least 20 times the power per average tone used to transmit the tone in the last second. Send within the band. Step 904 can include transmitting user data such as voice, text and user application data within the first frequency band in multiple tones.
In certain embodiments, each of steps 904 and 906 comprises transmitting at least one OFDM signal containing at least one complex symbol. In some embodiments, step 906 comprises manipulating the first transmitter to transmit at least two OFDM symbols. In some embodiments, the number of tones used to transmit within the second frequency band in step 906 is less than three. In certain embodiments, the information transmitted within the second frequency band in step 906 is transmitted in any one tone used by the first base station transmitter to transmit user data during the first period. Transmitter data transmitted with at least one tone and at least M times the amount of power, where M is a positive integer greater than 2, for example 3,5,6,10. , 20, 50 or some other number. The first transmission period includes a plurality of symbol transmission periods in one embodiment, the second transmission period includes at least one symbol transmission period in one embodiment, and the first transmission period includes more symbols than the second period. Includes transmission period.
Returning to step 908, in step 908, during the third period, the second base station transmitter is operated to transmit, for example, user data and / or other signals within the second frequency band. During the third period, the second base station transmitter does not transmit within the first frequency band. The first and third periods may have the same duration, but not necessarily the same duration, and may not be time-synchronized. The operation proceeds from step 908 to step 910. In step 910, the second base station transmitter is operated to transmit, for example, a beacon signal within the first frequency band in a fourth period shorter than the third period. The fourth period may have the same length as the second period, but may not necessarily have the same length. In some embodiments, the fourth period is at least one-fifth of the third period. In other embodiments, the fourth period is shorter than 1/10 of the third period, and in yet other embodiments, the fourth period is shorter than 1/100 of the third period. For the third period, other periods such as those discussed with respect to the first period are also possible. The operation returns from step 910 to step 908, or proceeds to optional step 911 if user data is transmitted within the second frequency band by the second transmitter over at least a portion of the fourth period. The sequences of steps 908 and 910 are repeated, for example, at regular intervals. Step 908 can include sending user data such as voice, text, and image data.
In some, but not all, embodiments, the first base station transmitter does not transmit within the first frequency band during the second period. In some embodiments, the second period is shorter than 1/20 of the first period. In certain embodiments, the first and second frequency bands are of the same size. In certain embodiments where the first and second frequency bands are of the same size, the method comprises the step of manipulating the first base station transmitter to transmit within the second frequency band during the second period. Transmission within the second frequency band will, depending on the specific embodiment, provide at least 5,10,20,30,40,50 or 60% of the transmitted power to 1 / of the second frequency band. Includes operations that focus on one or more tones that occupy less than five. In certain embodiments, the power transmitted in one tone of the second frequency band during the second period is transmitted by the transmitter in any other tone within the second frequency band during the second period. Includes at least twice the power of the
In certain embodiments, the operation of step 904 of operating the first base station transmitter to transmit within the first frequency band comprises transmitting user data within the first frequency band. The user data includes, for example, at least one of voice, text, and user application data. In certain embodiments, step 906 of manipulating the first base station transmitter to transmit within the second frequency band during the second period comprises transmitting transmitter information but not data for a particular user. .. In many embodiments, steps 904 and 906 each include operating the first base station transmitter to transmit at least one OFDM symbol, including at least one complex symbol.
In many embodiments, the number of complex symbols transmitted during the second period is less than 1/10 of the number of complex symbols transmitted during the first period.
In various embodiments, during the fourth period, the second base station transmitter does not transmit within the second frequency band. In certain embodiments, the second base station transmitter transmits user data, such as at least some voice or text data, during the third period. In some embodiments, the second base station transmitter transmits base station information, such as cell and sector identification information, during the fourth period, but does not transmit user data. In some embodiments, the first and second base station transmitters are in physically adjacent cells. In some embodiments, the first and second base station transmitters are in the same cell, with the execution of step 906 using the first base station transmitter and the execution of step 910 using the second base station transmitter. There is a fixed timing offset between them.
For example, consider the following typical embodiment using the method of Flowchart 900. The first base station is in the first cell and the second base station is in the adjacent cell of the same OFDM radio communication system. The first base station includes the first base station transmitter, and the second base station includes the second base station transmitter. The first frequency band is defined by the first base station as its canonical downlink signaling, such as traffic channel allocation signals, downlink pilot signals, other control signals, and at least one of voice, text, and user application data. A frequency band used for downlink traffic channel signals such as user data to wireless terminal devices, including one. The first frequency band contains at least a set of 113 consecutive tones. The second frequency band is provided by the second base station to its canonical downlink signaling, such as traffic channel allocation signals, downlink pilot signals, other control signals, and at least one of voice, text, and user application data. The frequency band used for the downlink traffic channel signal including one. The second frequency band is the same size as the first frequency band and contains at least a set of 113 consecutive tones. A set of 113 tones in the first frequency band does not overlap with a set of 113 tones in the second frequency band in some typical embodiments. In a typical system, an OFDM modulated symbol containing a complex symbol is transmitted using at least some of the tones.
In this particular typical embodiment, the operations of the first and second base station transmitters are not time-synchronized with each other, for example, the symbol transmission timing at the base station in the first cell is the base in the second cell. It may be different from the symbol transmission timing at the station. In this particular typical embodiment, each base station transmitter transmits normal signaling for 903 of each of its 904 consecutive OFDM transmission time intervals and each of its 904 consecutive OFDM transmissions. Sends a beacon signal during the remaining one of the time intervals. When the beacon signal is transmitted in this two-cell example, it is within the frequency band of the base station transmitter itself, for example the band normally used for signaling by the base station sector in which the transmitter is located. , Or transmitted by adjacent cells or sectors into the band normally used for signaling. This is another base station that normally uses a separate frequency band for signaling while a wireless terminal device with a single receiver chain continues to operate using its current connection point and current frequency band. Makes it possible to still obtain information about.
In various embodiments, for a given base station transmitter, the base station transmitter is one or more of its own band and the adjacent band corresponding to normal signaling by adjacent cells or sectors. A plurality of beacon signals can be alternately transmitted so as to transmit the beacon signals in order. This timing is repeated on a regular basis. The beacon signal is, in some embodiments, a high power signal, eg, in some embodiments, simply having more than two, three, or ten times the average power of the tones used to transmit user data. One tone. Due to the high level of power of the base station transmitter associated with the beacon signal, the beacon signal is easily detectable and recognizable to the wireless terminal device monitoring the downlink broadcast signaling from the base station. Different tones can be used by different base stations, allowing the WT to identify the source of the beacon signal. Normally, the beacon signal does not convey any specific user data, but instead conveys transmitter information such as transmitter identifier information and / or transmitter power level information.
As another example, consider the following typical embodiment using the method of Flowchart 900. Consider a typical OFDM communication system containing sectorized cells, each having two or more sectors. Each sectorized cell contains one or more base stations and a set of multiple base station transmitters, with one base station transmitter corresponding to each sector. Each base station transmitter may be part of its own base station, or multiple base station transmitters may be grouped together as part of a single base station. The first and second base station transmitters can correspond to adjacent sectors of the same cell. In such a typical embodiment, the first frequency band is voiced, texted by the first base station transmitter, with its legitimate downlink signaling such as, for example, traffic channel allocation signals, downlink pilot signals, other control signals. , And a frequency band used for downlink traffic channel signals such as user data to a wireless terminal device that includes at least one of the user application data. In this particular exemplary embodiment, the first frequency band comprises at least a set of 113 consecutive tones. In this particular embodiment, the second frequency band is provided by the second base station transmitter with its legitimate downlink signaling, such as traffic channel allocation signals, downlink pilot signals, other control signals, and voice, text, and user. The frequency band used for the downlink traffic channel signal containing at least one of the application data. The second frequency band, in this typical embodiment, is of the same size as the first frequency band and also includes a set of 113 consecutive tones. In this typical embodiment, the set of 113 tones in the first frequency band does not overlap with the set of 113 tones in the second frequency band. OFDM modulated symbols containing complex symbols are transmitted using at least some of these tones.
In this second particular example, the operations of the first and second base station transmitters in the same cell are time-synchronized with each other. In this example, each base station transmitter normally transmits signaling during most of the OFDM symbol transmission period, eg, 903 of each 904 consecutive OFDM symbol transmission time intervals, and much less. Beacon signals are transmitted during the symbol transmission time interval of, for example, during the remaining one of each 904 consecutive OFDM symbol transmission time intervals. When transmitted, the beacon signal is used for its normal signaling within the frequency band of the base station sector transmitter itself, which is the band normally used for signaling by the base station transmitter, or by adjacent cells. It is transmitted in the band. This is another adjacency that normally uses a separate frequency band for signaling while a wireless terminal device with a single receiver chain continues to operate using its current connection point and current frequency band. Makes it possible to still obtain information about base station transmitters. In this particular exemplary embodiment, the beacon signaling timing between adjacent sector base station transmitters in the same cell has a constant timing offset.
In this second example, for a given base station transmitter, the base station transmitter will, for example, beacon signals to its own band and to each of the adjacent bands corresponding to normal signaling by adjacent sectors of the same cell. A plurality of beacon signals can be transmitted alternately so as to transmit the signals in order. This timing is repeated on a regular basis. The beacon signal is a high power signal, eg, the signal described with respect to the previous example. Due to the high level of power associated with the beacon signal, the beacon signal is easily detectable and recognizable to the wireless terminal device monitoring the downlink broadcast signaling from the base station transmitter. Different tones can be used by different base stations, allowing the WT to identify the source of the beacon signal. Normally, the beacon signal does not convey any specific user data, but conveys transmitter information such as transmitter identifier information and / or transmitter power level information.
Many variations are possible according to the present invention with respect to the details of the embodiments. For example, a set of tones used for downlink signaling within one frequency band can include a number other than 113 tones, such as a much larger 1000 tones. In some embodiments, the ratio of time spent for beacon signaling by the base station transmitter to non-beacon downlink signaling may differ from 1/903, but the ratio of beacon to non-beacon transmitter signaling time is not necessarily. At least 1/5 in most, if not all, embodiments. In some embodiments, for example, a set of two or several tones constitutes one beacon signal instead of a single tone.
Various representative embodiments of using the present invention have been discussed above. However, these are only a few of the many possible embodiments that can be performed in accordance with the present invention.
Examples of various methods of the present invention are described as a series of steps. Some embodiments include performing various steps. The various combinations of steps are described below with various references to the groups prior to the steps.
Some typical methods are described, including various possible combinations of steps. The following methods are representative, and these are not the only combinations of methods and / or steps that can be included in the present invention.
Although described in connection with OFDM systems, the methods and devices of the invention are applicable to a variety of communication systems, including many non-OFDM and / or non-cellular systems.
In various embodiments, the nodes described herein are one or more of the present invention, such as, for example, signal processing, beacon generation, beacon ID, beacon measurement, beacon comparison, handoff, message generation and / or transmission steps. It is implemented using one or more modules that perform the steps corresponding to the above method. In certain embodiments, various features of the invention are realized using modules. Such modules may be implemented using software, hardware or a combination of software and hardware. Many of the methods or method steps control machines such as general purpose computers with or without additional hardware to perform all or part of the method, eg, on one or more nodes. It can be executed using machine-executable instructions such as software contained in machine-readable media such as storage devices such as RAM and floppy (registered trademark) disks. Accordingly, the present invention is particularly directed to machine-readable media, including machine-readable instructions for causing a machine, such as a processor and associated hardware, to perform one or more steps of the above method.
The system of the present invention is for controlling various elements of the system of the present invention to perform each of the various steps described above performed according to the method of the present invention, such as a control circuit and / or control software. Includes control module. Different steps of the control routine or different elements of the control circuit can control different actions, such as performing different method steps. Thus, the control module can include multiple means for performing one or more steps in accordance with the present invention, eg, a block of code.
In view of the above description of the present invention, many additional variations with respect to the methods and devices of the present invention described above will be apparent to those skilled in the art. Such variations should be considered within the scope of the present invention. The methods and devices of the present invention, along with CDMA, Orthogonal Frequency Division Multiple Access (OFDM), and / or various other types of communication techniques that can be used to provide wireless communication links between access nodes and mobile nodes. It can be used, and in practice it is used in various embodiments. In some embodiments, the access node is implemented as a base station that establishes a communication link with the mobile node using OFDM and / or CDMA. In various embodiments, the mobile node is a notebook computer, personal digital assistant (PDA), or other portable device that includes a receiver / transmitter circuit and logic and / or routine to perform the methods of the invention. Is realized as.
<figref num="1">FIG. 5 is a diagram of a typical 3-sector multicarrier cell including a sectorized base station and a wireless terminal device currently located at a sector boundary, wherein the base station and the wireless terminal device are in accordance with a typical embodiment of the present invention. It will be realized.</figref><figref num="2">FIG. 5 is a diagram of a representative multicarrier radio communication system implemented in accordance with the present invention, comprising three representative cells, each containing a sectorized base station, wherein the system also includes a representative radio terminal device currently located at the cell boundary. Includes.</figref><figref num="3">Representative signaling of a base station sector transmitter to frequencies for various sector transmitters of a representative cell according to the present invention is shown.</figref><figref num="4">Representative signaling of a base station sector transmitter to frequencies for sector transmitters of the same type name in a plurality of different cells according to the present invention is shown.</figref><figref num="5">FIG. 5 is a diagram of typical signaling of a base station sector transmitter over time for three representative frequency bands of two adjacent base station sector transmitters according to a representative embodiment of the present invention.</figref><figref num="6">FIG. 5 is a diagram of a typical multicarrier sectorized wireless communication system using the method of the present invention, realized in accordance with the present invention.</figref><figref num="7">It is a figure of a typical base station using the method of this invention realized according to this invention.</figref><figref num="8">It is a figure of the typical wireless terminal apparatus which uses the method of this invention realized according to this invention.</figref><figref num="9">It is a figure of the typical method of operating a base station according to the method of this invention.</figref>
Code description
100 3 sector cell, 102,208,210,212,606,608,700 base station, 104,232 wireless terminal equipment, 106,108,110,220,602 sector, 200 wireless communication system
9 sheets
Sheet 1 Sheet 2 Sheet 3 Sheet 4 Sheet 5 Sheet 6 Sheet 7 Sheet 8 Sheet 9
Every citation, both ways
| Document | Relation | Office |
|---|---|---|
| JP63048925A | Cites | Japan |
| JP11113049A | Cites | Japan |
| JP09501038A | Cites | Japan |
| JP01225237A | Cites | Japan |
| JP2001517907A | Cites | Japan |
77 members in 18 offices
Priority claims14
| Document | Office | Kind | Date |
|---|---|---|---|
| 51196403 | United States of America | P | |
| 51196403 | United States of America | P | |
| 60511964 | United States of America | – | |
| 10964908 | United States of America | – | |
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| 96490804 | United States of America | A | |
| 2004034305 | United States of America | W | |
| 2004034305 | United States of America | W | |
| 2003511964 | – | – | – |
| 2004964908 | – | – | – |
| 2004034305 | – | – | – |
| US20030511964P | – | – | – |
| US20040964908 | – | – | – |
| WO2004US34305 | – | – | – |
Members77
| Document | Office | Kind | |
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| CA2536218A1 | Canada | A1 | |
| CA2536261A1 | Canada | A1 | |
| WO2004019529A2 | World Intellectual Property Organization (WIPO) | A2 | |
| WO2004019537A2 | World Intellectual Property Organization (WIPO) | A2 | |
| WO2004019538A2 | World Intellectual Property Organization (WIPO) | A2 | |
| AU2003265672A1 | Australia | A1 | |
| AU2003265673A1 | Australia | A1 | |
| AU2003265673A8 | Australia | A8 | |
| AU2003270001A1 | Australia | A1 | |
| AU2003270001A8 | Australia | A8 | |
| WO2004019529A3 | World Intellectual Property Organization (WIPO) | A3 | |
| WO2004019537A3 | World Intellectual Property Organization (WIPO) | A3 | |
| US2004095880A1 | United States of America | A1 | |
| US2004095902A1 | United States of America | A1 | |
| US2004095904A1 | United States of America | A1 | |
| US2004109432A1 | United States of America | A1 | |
| WO2004019538A3 | World Intellectual Property Organization (WIPO) | A3 | |
| US2005085265A1 | United States of America | A1 | |
| AU2004306920A1 | Australia | A1 | |
| CA2542614A1 | Canada | A1 | |
| WO2005039094A2 | World Intellectual Property Organization (WIPO) | A2 | |
| EP1540865A2 | European Patent Office (EPO) | A2 | |
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| US6993333B2 | United States of America | B2 | |
| US2006052108A1 | United States of America | A1 | |
| EP1673876A2 | European Patent Office (EPO) | A2 | |
| MXPA06004133A | Mexico | A | |
| NO20062173L | Norway | L | |
| HK1083949A1 | Hong Kong, China | A1 | |
| IL174939D0 | Israel | D0 | |
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| CN1883125A | China | A | |
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| AU2004306920C1 | Australia | C1 | |
| EP1540865A4 | European Patent Office (EPO) | A4 | |
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| US2011116358A9 | United States of America | A9 | |
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| CA2536218C | Canada | C | |
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| EP1673876B1 | European Patent Office (EPO) | B1 | |
| US8693304B2 | United States of America | B2 | |
| JP5496778B2 | Japan | B2 |
20 legal events, as the office reported them to INPADOC
Over the term
Point at a mark for the eventEvents
| Event | Code | |
|---|---|---|
| Cancellation because of no payment of annual feesLAPS | LAPS | |
| Receipt of annual feesJAPANESE INTERMEDIATE CODE: R250R250 | R250 | |
| Receipt of annual feesJAPANESE INTERMEDIATE CODE: R250R250 | R250 | |
| Receipt of annual feesJAPANESE INTERMEDIATE CODE: R250R250 | R250 | |
| Receipt of annual feesJAPANESE INTERMEDIATE CODE: R250R250 | R250 | |
| Renewal fee payment (event date is renewal date of database)FPAY | FPAY | |
| Certificate of patent or registration of utility modelJAPANESE INTERMEDIATE CODE: R150R150 | R150 | |
| First payment of annual fees (during grant procedure)JAPANESE INTERMEDIATE CODE: A61A61 | A61 | |
| Written decision to grant a patent or to grant a registration (utility model)JAPANESE INTERMEDIATE CODE: A01A01 | A01 | |
| Written decision to grant a patent or to grant a registration (utility model)JAPANESE INTERMEDIATE CODE: A01A01 | A01 | |
| Decision of grant or rejection writtenTRDD | TRDD | |
| Written amendmentJAPANESE INTERMEDIATE CODE: A523A521 | A521 | |
| Written permission of extension of timeJAPANESE INTERMEDIATE CODE: A602A602 | A602 | |
| Written request for extension of timeJAPANESE INTERMEDIATE CODE: A601A601 | A601 | |
| Notification of reasons for refusalJAPANESE INTERMEDIATE CODE: A131A131 | A131 | |
| Written amendmentJAPANESE INTERMEDIATE CODE: A523A521 | A521 | |
| Report on retrievalJAPANESE INTERMEDIATE CODE: A971007A977 | A977 | |
| Notification of change in applicantJAPANESE INTERMEDIATE CODE: A711A711 | A711 | |
| Notification of change in applicantJAPANESE INTERMEDIATE CODE: A712A711 | A711 | |
| Written request for application examinationJAPANESE INTERMEDIATE CODE: A621A621 | A621 |
Numbers
- Publication
- 4690333
- Publication, DOCDB
- 4690333
- Publication, EPODOC
- JP4690333B
- Application
- 2006535398
- Application, DOCDB
- 2006535398
- Application, EPODOC
- JP20060535398
Titles2
- Japanese
- 多搬送波無線通信システムにおいてセクタ間及び/又はセル間のハンドオフを改善する方法及び装置
- English
- Methods and Devices for Improving Sector-to-Sector and / or Cell-to-Cell Handoffs in Multicarrier Wireless Communities
Classification
- CPC, 9
- H04W36/0072
- H04L5/0042
- H04L5/0048
- H04L5/0053
- H04L27/2602
- H04W36/08
- H04L5/0007
- H04W52/40
- H04W36/36
- IPC, 8
- H04W36 00
- H04W36 36
- H04W52 32
- H04W88 08
- H04J11 00
- H04B1 38
- H04L
- H04W36 08
