Spatial pilot structure for multi-antenna wireless communication

Related technology

[Priority claim under 35 USC Article 119] This patent application is the "Wireless Communication System and Method" of Provisional Application No. 60 / 775,443 filed on February 21, 2006, which is assigned to the assignee of the present application and expressly incorporated herein by reference. It claims priority based on the "DO Communication System and Method" of No. 60 / 775,693.

This disclosure relates generally to communications, and more specifically to transmission techniques for wireless communication systems.

Wireless communication systems are widely deployed to provide various communication services such as voice, video, packet data, messaging and broadcasting. These systems may be multiple access systems that can support multiple users by sharing available system resources. Examples of such multiple access systems include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal FDMA (OFDMA) systems, and single carrier FDMA (SC). -FDMA) There is a system.

The multiple access system can use one or more multiplexing methods such as code division multiplexing (CDM) and time division multiplexing (FDM). The system is deployable and can help existing terminals. It is desirable to improve the performance of the system while maintaining compatibility with older versions of existing terminals. To improve throughput and / or stability by leveraging the additional spatial dimensions provided by the use of multiple antennas, for example, Multiple Input-Multiple Output (MIMO) and Spatial Access Multiple Access (SDMA). It is desirable to use a spatial technique such as).

Therefore, there is a need in the field of transmission technology that can support advanced communication technology (eg, spatial technology) while maintaining compatibility with older versions of existing terminals.

[Outline of Invention] Techniques for efficiently transmitting data in wireless communication systems are described here. This technique uses a slot structure that is compatible with older versions of existing designs. The technology also efficiently supports spatial technology and / or other advanced communication technologies by using Orthogonal Frequency Division Multiplexing (OFDM).

In one aspect, a device is described that determines the time-frequency resources available for OFDM, excluding the time-frequency resources used for traffic data and signaling transmitted in CDM. The device allocates time-frequency resources available for OFDM to at least one terminal and exchanges data with each terminal via the time-frequency resources assigned to that terminal.

Another aspect describes a device that receives an allocation of time frequency resources selected from the time frequency resources available for OFDM, excluding the traffic data transmitted by CDM and the time frequency resources used for signaling. .. This device exchanges data via the time frequency within its allocation.

The various aspects and features of this disclosure are described in more detail below.

[Detailed description] The transmission techniques described herein can be used in various wireless communication systems such as CDMA, TDMA, FDMA, OFDMA and SC-FDMA systems. The terms "system" and "network" are often used interchangeably. CDMA systems can implement broadcasting technologies such as cdma2000, Universal Terrestrial Access (UTRA), and Evolved UTRA (E-UTRA). cdma2000 covers IS-2000, IS-95 and IS-856 standards. UTRA includes wideband CDMA (W-CDMA) and low chip rate (LCR). TDMA systems can implement broadcasting technologies such as the Mobile Communications Global System (GSM). OFDMA systems can implement broadcast technologies such as Long Term Evolution (LTE) (which is part of E-UTRA), IEEE802.20, and Flash-OFDM®. UTRA, E-UTRA, GSM and LTE are described in documents from organizations called "3rd Generation Joint Projects" (3GPP). cdma2000 is described in a document from an organization called "3rd Generation Partnership Project 2" (3GPP2). These various broadcasting technologies and standards are known in the art.

For clarity, various aspects of the technology are described below for high rate packet data (HRPD) systems that implement IS-856. HRPD is also referred to as Evolution Data Optimization (EV-DO), Data Optimization (DO), High Data Rate (HDR), and so on. The terms HRPD and EV-DO are often used interchangeably. Currently, HRPD Revised Editions (Revs.) 0, A and B have been standardized, HRPD Revs. 0 and A have been deployed, and HRPD Revs. C is under development. HRPD Revs. 0 and A cover a single carrier HRPD (1x HRPD). HRPD Rev.B covers multi-carrier HRPD and is compatible with HRPD Revs.0 and A and older versions. The techniques described here can be incorporated into any improved version of HRPD. For clarity, HRPD technology is used in many of its technologies below.

FIG. 1 shows an HRPD communication system 100 having multiple access points 110 and multiple terminals 120. The access point fixed station der communicates with normal terminals can is, also the base station, also referred to as like Node B. Each access point 110 provides communication coverage for a particular geographic area and supports communication for terminals located within that coverage area. The access point 110 may be coupled with a system controller 130 that provides coordinates and controls these access points. The system controller 130 may have network entities such as a base station controller (BSC), a packet control function (PCF), and a packet data serving node (PDSN).

The terminals 120 are distributed throughout the system, and each terminal can be fixed or mobile. In addition, the terminal can be referred to as an access terminal, a mobile station, user equipment, a subscriber unit, a station, and the like. The terminal may be a cellular telephone, a personal digital assistant (PDA), a wireless device, a handheld device, a wireless modem, a laptop computer, or the like. The terminal can support any improved version of HRPD. In HRPD, a terminal can receive transmissions on a forward link from one access point at any given moment, and can send transmissions on a reverse link to one or more access points. A forward link (or downlink) refers to a communication link from the access point to the terminal, and a reverse link (or uplink) refers to the communication link from the terminal to the access point.

Figure 2 shows a slot structure 200 that supports CDM on the forward link in HRPD. The transmission timeline is divided into slots. Each slot has a duration of 1.667 milliseconds (ms) and spans 2048 chips. Each chip has a duration of 813.8 nanohours (ns) for every 1.2288 megachips / hour (Mcps) chip rate. Each slot is divided into two identical half slots. Each half-slot consists of (i) a pilot segment in the center of the half-slot, an overhead segment consisting of two media access control (MAC) segments on either side of the pilot segment, and (ii) two traffic segments on both sides of the overhead segment. Has. Traffic segments can also be referred to as traffic channel segments, data segments, data fields, and so on. The pilot segment carries the pilot and has a duration of 96 chips. Each MAC segment carries signaling (eg, reverse power control (RPC) information) and has a duration of 64 chips. Each traffic segment carries traffic data (eg, unicast data about a particular terminal, broadcast data, etc.) and has a duration of 400 chips.

HRPD Revs. 0, A and B use CDM for data sent in the traffic segment. The traffic segment can carry CDM data for one or more terminals served by the access point. To generate the data symbols, the traffic data for each terminal can be processed based on the modulation parameters determined by the coding and the channel footback received from that terminal. Data symbols for one or more terminals are demultiplexed and covered with a 16-chip Walsh function or code to generate CDM data for the traffic segment. Then, the CDM data is generated in the time domain using the Walsh function. The CDM traffic segment is a traffic segment that carries CDM data.

It is desirable to use OFDM and / or single carrier frequency division multiplexing (SC-FDM) for data sent in the traffic segment. OFDM and SC-FDM divide the available bandwidth into multiple orthogonal subcarriers, also referred to as tones, binaries, and so on. Each subcarrier can be modulated with data. Generally, modulation symbols are sent in the OFDM frequency domain and the SC-FDM time domain. OFDM and SC-FDM have certain desirable properties, such as the ability to easily reduce intersymbol interference (ISI) caused by frequency selective fading. OFDM can also efficiently support MIMO and SDMA, which can be applied independently on each subcarrier and can provide good operation on the frequency selection channel. it can. For clarity, the use of OFDM to transmit data is described below.

It is desirable to support OFDM while maintaining compatibility with HRPD Revs. 0, A and B and older versions. In HRPD, the pilot and MAC segments can be demodulated by all active terminals at any time, while the traffic segment is demodulated only by the serving terminal. Therefore, compatibility with older versions can be achieved by maintaining the pilot and MAC segments and modifying the traffic segment. By substituting the CDM data for a traffic segment of a given 400 chips with one or more OFDM symbols with a total duration of 400 chips or less, the OFDM data can be transmitted in an HRPD waveform.

Figure 3 shows a slot structure 300 that supports OFDM and CDM in HRPD. For simplicity, only one half slot is shown in Figure 3. The half-slot has (i) an overhead segment consisting of a 96-chip pilot segment and two 64-chip MAC segments, and (ii) two traffic segments on both sides of the overhead segment. Each traffic segment is sent at a 400 chip traffic interval and the overhead segment is sent at a 224 chip overhead interval. In some designs, CDM or OFDM can be selected for each traffic segment. In this design, each traffic segment can carry CDM data when CDM is selected, or one or more OFDM symbols when OFDM is selected. In another design, the traffic segment can carry both CDM and OFDM data. For example, a traffic segment can carry CDM data in half of the traffic segment and one or more OFDM symbols in the other half of the traffic segment.

In general, OFDM symbols can be generated based on various OFDM symbol numerologies or designs. Each OFDM symbol numerology is associated with specific values for appropriate parameters such as OFDM symbol duration, number of subcarriers, and periodic prefix length. The OFDM symbol duration should be an integer divisor of the 400-chip traffic segment to fully use the traffic segment. In addition, the sample rate of the OFDM symbol should be a multiple of an integer of the CDM chip rate to simplify processing on the access point and terminal.

Table 1 shows three examples of "normal" OFDM symbol numerologies 1, 2 and 3 that can be used for traffic intervals in HRPD and "long" OFDM symbol numerologies 1 and 2 2 that can be used for overhead intervals in HRPD. List two examples. These numerologies are selected to be compatible in HRPD slot structure and chip rate, so (i) integers of OFDM symbols are transmitted in traffic or overhead segments, and (ii) sample rates for OFDM symbols are chips of CDM data. It is a multiple of the integer of the rate. These numerologies are further selected so that the number of subcarriers that determines the Discrete Fourier Transform (DFT) size can efficiently generate OFDM symbols. For these numerologies, the number of subcarriers is not a power of 2, but has a small prime factor. For example, 90 subcarriers can be obtained with prime factors 2, 3, 3 and 5. A small prime factor allows for an efficient mixed basis Fourier transform (FFT) implementation and produces an OFDM symbol. In Table 1, n is a positive interval value that depends on the spectral arrangement. The numerology shown in Table 1 enables efficient embedding of OFDM data in HRPD waveforms. Any normal OFDM symbol numerology can be used to replace CDM data with OFDM data at traffic intervals. Any long OFDM symbol numerology can be used to transmit OFDM data at overhead intervals. Other OFDM symbol numerologies can also be used for traffic and overhead segments.<tables num="1"><img file="JP5113085B2_D0001.tif" /></tables>

FIG. 4 shows a slot structure 400 that supports OFDM and CDM of a single HRPD carrier in a 5 MHz spectral arrangement. In the example shown in Figure 4, the single HRPD carrier is located near one end of the 5MHz spectral allocation. Pilot and MAC segments for the HRPD carrier are transmitted in the center of the half slot. Each of the two traffic segments of the HRPD carrier can transmit CDM data and / or OFDM data.

The OFDM spectrum can be defined to include all available spectra in the spectrum assignment except for any HRPD carrier. In the example shown in FIG. 4, the OFDM spectrum includes the available spectra on both sides of a single HRPD carrier. In general, up to three HRPD carriers can be sent with a spectrum allocation of 5 MHz, and the OFDM spectrum can then exclude all of the HRPD carriers.

Normal OFDM symbols can be generated for each OFDM symbol period at traffic intervals. The normal OFDM symbol period is 200 chips in the normal OFDM symbol numerology 2 in Table 1. The normal OFDM symbol is (i) a subcarrier corresponding to the traffic segment used in OFDM and (ii) a subcarrier in the OFDM spectrum, which can carry OFDM data. Normal OFDM symbols can be nulled out on the subcarrier corresponding to the traffic segment with CDM data.

Long OFDM symbols can be generated for each OFDM symbol period in the overhead interval. The long OFDM symbol period is 224 chips in the long OFDM symbol numerology 2 in Table 1. Long OFDM symbols can carry OFDM data on a subcarrier of the OFDM spectrum and can be nulled out on the subcarrier corresponding to the overhead segment sent by CDM.

The OFDM spectrum can be used to implement an OFDMA channel that can operate independently of the traffic and overhead segments in legacy HRPD. In FIG. 4, the logical channel Ch1 has a traffic segment with respect to the HRPD carrier, and the logical channel Ch2 can correspond to the OFDMA channel. OFDMA channels can take advantage of various features commonly used in pure OFDM systems that use only OFDM for transmission. For example, the time frequency resources available for an OFDMA channel can be divided into blocks, which can be assigned to terminals.

Figure 5A shows the design of the tile structure 500 that can be used in the HRPD slot structure shown in Figure 2. The tile structure 500 covers one HRPD carrier in one half slot and has two traffic segments and an overhead segment shown in FIG. The tile structure 500 is also based on the normal OFDM symbol numerology 2 and the long OFDM symbol numerology 2 shown in Table 1. For this design, the traffic segment covers two normal OFDM symbols and spans 180 subcarriers with an exponent of 1 to 180. The overhead segment covers one long OFDM symbol and spans 200 subcarriers with an exponent of 1 to 200.

The time frequency resources available on one HRPD carrier in one half slot can be divided into multiple tiles. Tiles can also be referred to as time frequency blocks, resource blocks, and so on. It is desirable to have tiles of equal size (or approximately equal size) so that data processing does not depend on which tiles are assigned. In the design shown in Figure 5A, this available time frequency resource is divided into 8 tiles-4 "even" tiles and 4 "odd" tiles.

FIG. 5B shows a pair of even and odd tiles of the tile structure 500 shown in FIG. 5A. Each tile covers an average of 22.5 continuous subcarriers per normal OFDM symbol and 25 subcarriers for long OFDM symbols over a 833 μs half slot. Therefore, each tile has 90 resource units in the two traffic segments and 25 resource units in the overhead segment. A resource unit is one subcarrier in one OFDM symbol period and is useful for transmitting one modulation symbol. The even and odd tiles, which are more correlated by mirror symmetry, make each tile pseudo-orthogonal. Therefore, the design features of even tiles are easily incorporated into odd tiles.

The time frequency resources available for OFDM can also be divided in other ways. In other designs, the available time frequency resource is divided into 6 tiles, each tile with 30 subcarriers per normal OFDM symbol and 33 or 34 subcarriers per long OFDM symbol, respectively. Cover. In yet another design, the available time-frequency resources are divided into five tiles, each of which covers 36 subcarriers per normal OFDM symbol and 40 subcarriers per long OFDM symbol. The time frequency resources available in a slot, or some duration that replaces a half slot, can also be divided into tiles. In general, tiles may be of any duration and may cover any number of subcarriers. The tile can have a continuous subcarrier (as shown in FIGS. 5A and 5B) or a subcarrier arranged across the OFDM spectrum. The tile may have a non-orthogonal shape with different numbers of subcarriers with different symbol periods, which may be (i) non-homogeneous subcarrier divisions across the OFDM symbol period and / or (ii). It may be due to the use of different OFDM symbol numerologies in different OFDM symbol periods. For clarity, the following description assumes the use of even and odd tiles shown in FIGS. 5A and 5B.

5A and 5B show the tile structure 500 for one HRPD carrier, i.e. n = 1 in Table 1. In general, the tile structure can be defined by any number of HRPD carriers or any value of n. For example, the tile structure 500 can be scaled by n and can have 8n tiles in each half slot.

The available tiles can be assigned to the terminal for transmission. In general, terminals can be assigned 0,1, or multiple tiles at predetermined scheduling intervals (eg, half slots) that depend on the terminal's data needs, tile availability, and so on. The access point can send traffic data, signaling and / or pilots to the terminal in the assigned tiles. Pilots are a priori known to both access points and terminals and can be used for channel estimation, noise and / or interference estimation, coherent data demodulation or detection, and / or other purposes. A pilot can be transmitted based on a pilot pattern that directs a particular resource unit to use it to transmit the pilot symbol. The resource unit used to transmit the pilot symbol is referred to as the pilot tone in the following description.

The access point can send pilot symbols in pilot tones on the tile. The terminal can estimate the channel gain for the pilot tone based on the pilot symbol received from the access point. Based on the channel gain estimated for the pilot tone (eg, by performing time-frequency interpolation), the channel gain for other resource units in the tile can be derived. If the number of degrees of freedom of the radio channel is lower than the number of pilot tones in the tile, the pilot tones that do not need to estimate the channel gain can be used to estimate the noise and interference power in the tile.

In general, the pilot pattern may have any number of pilot tones and the pilot tones may be placed anywhere in the tile. The number of pilot tones can be selected based on the trade-off between pilot overhead and channel estimation performance. The placement of pilot tones may be based on various considerations such as delayed diffusion, Doppler diffusion, support for spatial multiplexing techniques such as MIMO and / or SDMA.

Pilot tone spacing in the frequency domain can be selected based on the predicted delayed spread of the radio channel, where delayed spread is the reciprocal of the coherent bandwidth. Smaller frequency separations between pilot tones can be used to handle larger delay spreads. Pilot tone spacing in the time domain is selected based on the predicted Doppler spread of the radio channel, where Doppler spread is proportional to terminal speed and carrier frequency. Smaller time separations between pilot tones can be used to handle larger Doppler diffusion.

Pilot tones can also be placed to support spatial multiplexing techniques such as MIMO and SDMA in forward and reverse links, and pseudo-orthogonal multiplexing in reverse links. Spatial multiplexing allows multiple data streams to be transmitted simultaneously via multiple spatial channels or layers formed by multiple transmit and receive antennas. Pilot tones can be clustered within tiles to support spatial multiplexing. The number of pilot tones in each cluster may be equal to or greater than the spatial rank to be supported. Spatial rank refers to the number of spatial channels in a radio channel, so the number of data streams can be transmitted in parallel over the radio channel. The spatial rank can be given by S min {T, R}, where T is the number of transmitting antennas, R is the number of receiving antennas, and S is the spatial rank.

In each cluster, the channel response can be assumed to be stable across the pilot tone. The pilot tone of each cluster can be used to estimate the channel gain of different data streams / layers or transmit antennas. In the first design, T transmit antennas can be assigned T different pilot tones to the cluster, with one pilot tone and pilot symbol per transmit antenna assigned to that antenna from each transmit antenna. Can be transmitted in tone. In the second design, pilot code-based multiplexing can be used for different data streams / layers or transmit antennas. In this design, the pilot of each stream / antenna is a quadrature code and can be spread across all pilot tones of the entire cluster. For example, a stream or antenna pilot symbol can be spread across three pilot tones in a cluster (eg, pilot pattern format 0 in Figure 6A below) in columns of a 3x3 DFT matrix. The second design has improved channel estimation accuracy (when the number of streams or antennas is less than the cluster size), and constant signal and interference power spectral density beyond the first design with one pilot tone per antenna. It can provide certain advantages such as. The second design uses a continuous structure of each pilot cluster to achieve orthogonality in the presence of changes in time and / or frequency channels. Stream and antenna pilots can also be transmitted in other ways.

Different pilot patterns can be defined, for example, for different delay spreads, Doppler spreads and channel conditions with different spatial ranks. Time and frequency separation between different clusters can be selected based on each of the expected Doppler and delayed spreads of the radio channel. Some example pilot patterns are given below. For each pilot pattern, the placement of pilot tones is given for even and odd tiles in Figure 5B (which is a non-orthogonal tile) and is equivalent to covering 16 subcarriers in 8 symbol periods. Given for 16x8 orthogonal tiles.

Figure 6A shows a pilot pattern 600 for format 0, which supports medium delayed diffusion (eg, for OFDM symbol numerology 2 in Table 1, up to 2.5 μs) and up to 3 spatial ranks. In the pilot pattern 600, 18 pilot tones are arranged in 3 clusters of 6 each. Two clusters are placed at the top of the tile, the other two are placed closer to the center of the tile, and the last two clusters are placed at the bottom of the tile. The three pilot tones in each cluster can be used to estimate the channel gain for up to three spatial channels.

Figure 6B shows a format 1 pilot pattern 610, which supports larger delayed diffusion (eg, up to 6 μs for OFDM symbol numerology 2 in Table 1) and up to two spatial ranks. In the pilot pattern 610, two 24 pilot patterns are arranged in 12 clusters each. Six pairs of clusters are formed and placed across the 22.5 subcarriers of the tile. Each pair contains one cluster on the left half of the tile and the other cluster on the right half of the tile. Smaller frequency separation between pilot tones supports greater delay diffusion. Two pilot tones in each cluster can be used to estimate channel gain for two spatial channels.

Figure 6C shows a format 2 pilot pattern 620, which supports medium delayed diffusion and up to four spatial ranks. In Pilot 620, 24 pilot tones are arranged in 4 clusters of 6 each. Two clusters are placed at the top of the tile, the other two are placed near the center of the tile, and the last two clusters are placed at the bottom of the tile. The four pilot tones of each cluster can be used to estimate the channel gain over the four spatial channels.

Figure 6D shows a format 3 pilot pattern 630, which supports larger delay spreads and up to four spatial ranks. In the pilot pattern 630, 48 pilot tones are arranged in 4 of 12 clusters each. Six pairs of clusters are formed and placed on tiles across 22.5 subcarriers.

Figure 6E shows a format 4 pilot pattern 640, which supports large delayed diffusion (eg, up to 9 μs for OFDM symbol numerology 2 in Table 1) and up to two spatial ranks. In pilot pattern 640, 32 pilot tones are placed in two 16 clusters. Eight pairs of clusters are formed and placed across the 22.5 subcarriers of the tile. Reducing the frequency separation between pilot tones supports greater delay diffusion.

Figure 6F shows a format 5 pilot pattern 650, which supports large delay spreads and up to four spatial ranks. In the pilot pattern 650, 64 pilot patterns are arranged in 4 clusters of 16 each. The two clusters at the bottom of the even tiles and at the vertices of the odd tiles contain the pilot tones of the overhead segment.

Figure 6G shows a format 6 pilot pattern 660, which supports an additional large delay spread (up to 13 μs for OFDM symbol symbol numerology 2 in Table 1) and up to two spatial ranks. In the pilot pattern 660, 48 pilot tones are arranged in two clusters of 24 each. The two clusters at the bottom of the even tiles and at the vertices of the odd tiles contain pilot tones that are close and diagonal.

Table 2 summarizes the seven pilot patterns shown in FIGS. 6A-6G and provides supported delay diffusion, supported spatial ranks and pilot overhead for non-orthogonal and orthogonal tiles. Table 2 shows similar overheads for different pilot patterns on non-orthogonal and orthogonal tiles. Orthogonal tile pilot patterns may also extend to non-orthogonal tiles in a manner similar to other OFDM symbol numerologies, such as the normal OFDM symbol numerologies 1 and 3 in Table 1.<tables num="2"><img file="JP5113085B2_D0002.tif" /></tables>

6A-6G show seven example pilot patterns that can be used for the odd and even tiles shown in FIGS. 5A and 5B. Other pilot patterns can also be defined for these odd and even tiles. Other tiles can also be defined for the time frequency resources available for OFDM, and suitable pilot patterns can be defined for these other tiles.

The system can support a set of pilot patterns designed for different channel conditions and spatial ranks. Appropriate pilot patterns can be selected for the terminal based on the applicable channel conditions and spatial rank for the terminal. Whenever the channel conditions and / or spatial rank change sufficiently to obtain a change in pilot pattern, a new pilot pattern can be selected for the terminal. The pilot pattern can be selected by any entity (access point or terminal) that has access to the appropriate information to make the selection.

The tiles and pilot patterns described herein can be used to transmit on forward links as well as on reverse links. In reverse link, the terminal can transmit the access point with a dedicated pilot in the pilot tone on the tile assigned to the terminal. On the forward link, the access point can send a dedicated pilot to the terminal with a pilot tone on the tile assigned to that terminal.

The access point can also send a common pilot available to all terminals within the access point's coverage. For example, the access point may send a common pilot on all P subcarriers in each OFDM symbol period, where P may be equal to 4,8 or any other suitable value. If there are multiple antennas, the access point circulates through the antenna across frequency and / or time. In an example of two antennas, the access point is the first on all 16 subcarriers, with the subcarrier used for the second antenna combined with the subcarrier used for the first antenna. A common pilot can be transmitted from one antenna and a common pilot can be transmitted from a second antenna on all 16 subcarriers.

The system can support frequency hopping for OFDM channels, allowing data transmission to be well tolerated by harmful path effects such as frequency selective fading, narrowband interference, jamming, etc. In frequency hopping, different tiles in different parts of the OFDM spectrum may be assigned to terminals at different scheduling intervals, eg, in different half slots.

FIG. 7 illustrates frequency hopping in the time-frequency plane for one HRPD carrier with the tiles shown in FIGS. 5A and 5B. In this example, eight tiles with an exponent of 1 to 8 may be defined for each half slot and assigned to different terminals. The terminal can be assigned a specific sequence of tiles overtime. Different tiles may be selected in a pseudo-random or deterministic way for different half slots to achieve frequency diversity. To randomize cell-to-cell interference, the sequence of tiles assigned to terminals in one cell may also be pseudo-random for the sequence of tiles assigned to terminals in adjacent cells.

Figure 8 shows the design of Process 800, which is executed by the access point for communication. Excluded time frequency resources available for OFDM and used for trafficking data and signaling sent in CDM can be determined (block 812). The time frequency resources available for OFDM can be allocated to at least one terminal (block 814). For block 814, the time frequency resources available for OFDM can be divided into multiple tiles. Each tile corresponds to a block of time frequency resources and may have a non-orthogonal shape, for example by using multiple OFDM symbol numerology. Each tile has a first section of time-frequency resources defined based on the first OFDM symbol numerology (eg, left traffic interval in Figure 5A) and a second OFDM symbol numerology (eg overhead interval in Figure 5A). ), And a third section of time-frequency resources defined based on the first OFDM symbol numerology (eg, the traffic interval on the right in Figure 5A). it can. At least one of the multiple tiles may be assigned to each terminal. Each terminal can also be assigned different multiple tiles overtime for frequency hopping to achieve frequency diversity and interference randomization. The pilot pattern can be selected for each terminal from multiple pilot patterns (block 816). Alternatively, each terminal can select the appropriate pilot pattern and propagate the selected pilot pattern to the access point. Multiple pilot patterns may support different delay spreads, and pilot patterns can be selected for each terminal based on the expected delay spread for that terminal. Multiple pilot patterns also support different spatial ranks, and for each terminal the pilot pattern can be selected based on the spatial rank for that terminal. Each pilot pattern may have multiple clusters of pilot tones arranged across the tile, while each pilot tone corresponds to one subcarrier in one symbol period used by the pilot. Multiple clusters of pilot tones for each pilot pattern may be arranged in different frequency arrangements and / or different time arrangements across the tile, for example as shown in FIGS. 6A-6G.

Data and pilots can be exchanged between each terminal via time-frequency resources in at least one tile assigned to that terminal (block 816). For forward links, data can be sent to each terminal in at least one tile assigned to that terminal, and pilots can send in at least one tile based on the pilot pattern selected for the terminal. be able to. For reverse links, data may be received from each terminal in at least one tile assigned to that terminal, and pilots may be received in at least one tile based on the pilot pattern selected for that terminal. You may. OFDM symbols can be processed (eg, for OFDM modulation or demodulation) for each assigned tile based on multiple OFDM symbol numerology. The common pilot can also be transmitted across the available time frequency resources for OFDM.

Figure 9 shows process 900 executed by the terminal for communication. The terminal is selected from the available time-frequency resources for OFDM and receives an allocation of time-frequency resources excluding the traffic data sent in CDM and the time-frequency resources used in signaling (block 912). This allocation may be made for tiles corresponding to blocks of time frequency resources, which may have a non-orthogonal shape. This allocation can also be made for different tiles overtime to achieve frequency hopping. The terminal can get a selection of pilot patterns from multiple pilot patterns (block 914). The pilot pattern can be selected by the terminal and carried to the access point, or can be selected by the access point and carried to the terminal. Data and pilots can be exchanged (eg, sent and / or received) via time frequency resources in the allocation (block 916). Because data is exchanged over allocated time frequency resources, OFDM symbols can be processed based on multiple OFDM symbol numerology. Pilot symbols can also be processed based on the selected pilot pattern.

Non-orthogonal tiles, pilot patterns for these tiles, and hopping of tiles in the time-frequency plane for fading / interference diversity are different design elements of how traditional OFDMA systems (with homogeneous OFDM symbol numerology and orthogonal tile structures). Shows whether OFDM components with heterogeneous symbolic numerology can be incorporated into existing signal waveforms (such as HRPD forward link waveforms) in a hybrid system that can be embedded in a seamless and older version in a compatible manner. Here are some examples.

FIG. 10 shows a block diagram of the design of the access point 110 and the terminal 120, which are one of the access points and terminals of FIG. For simplicity, only the processing unit for transmission over the forward link is shown in Figure 10. Also, for simplicity, the access point 110 and the terminal 120 are each indicated by one antenna. In general, each entity may be equipped with any number of antennas.

At the access point 110, the transmit (TX) data and signaling processor 1010 receives and processes traffic data and signaling (eg, encoding, interleaving and symbol mapping) and provides data symbols and signaling symbols, respectively. Data symbols are symbols for traffic data, signaling symbols are symbols for signaling, pilot symbols are symbols for pilots, and symbols are typically complex numbers. The pilot processor 1012 generates, for each terminal, a pilot symbol based on the pilot pattern selected for that terminal. The CDM / OFDM modulator 1020 receives data and signaling symbols from processor 1010 and pilot symbols from processor 1012, performs CDM and / or OFDM modulation based on the received symbols, and provides output samples. Modulator 1020 can use CDM to perform CDM processing on symbols transmitted in traffic and overhead segments. Modulator 1020 can perform OFDM processing on symbols transmitted on the time frequency resources used for OFDM. Transmitter (TMTR) 1022 processes the output sample from modulator 1020 (eg analog conversion, amplification, filtering, and frequency up-conversion) to generate a forward link signal, which is transmitted to antenna 1024. ..

At terminal 120, antenna 1052 receives a forward link signal from access point 110 and provides the received signal to receiver (RCVR) 1054. The receiver 1054 processes the received signal (eg, filters, amplifies, frequency downconverts, and digitizes) to provide a received sample. The CDM / OFDM demodulator (Demod) 1060 processes the received sample in a manner that is complementary to the processing by the CDM / OFDM modulator 1020. Demodulator 1060 may guide channel estimation for the radio channel between access point 110 and terminal 120 based on the receive pilot symbol. The demodulator 1060 may process the received sample for CDM and / or OFDM to obtain the received symbol, and then a symbol that is an estimate of the data symbol and signaling symbol transmitted by the access point 110 to the terminal 120. Data detection may be performed on the received symbol along with the channel estimation to obtain the estimation. Received (RX) data and signaling processor 1070 processes symbol estimation (eg, symbol demapping, deinterleaving, and decoding) to provide decoded data and signaling. In general, at access point 110, processing by the CDM / OFDM demodulator 1060 and RX data and signaling processor 1070 is complementary to processing by CDM / OFDM modulator 1020 and TX data and signaling processor 1010, respectively.

Controllers 1030 and 1080 instruct operations on the access point 110 and terminal 120, respectively. The memories 1032 and 1082 store the program code and data for the access point 110 and the terminal 120, respectively.

Those who are proficient in the art understand that information and signals may be represented using any variety of different techniques and techniques. For example, data, commands, instructions, information, signals, bits, symbols and chips that can be referenced through the description above are voltages, currents, electromagnetic waves, magnetic fields or magnetic powder, optical fields or particles, or any combination thereof. May be represented by.

Further, if you are skilled in the art, the various descriptible logical blocks, modules, circuits and algorithm steps described in connection with those disclosed herein are electronic hardware, computer software, or both. You will understand that it can be implemented as a join. To articulate this hardware-software compatibility, various descriptible components, blocks, modules, circuits and steps have been generally described above with respect to their functionality. Whether such functionality is implemented as hardware or software depends on the design constraints imposed on the particular application and the entire system. A skilled technician may implement this described functionality in a variety of ways for a particular application, but such implementation decisions are to be construed as causing a departure from the scope of this disclosure. Should not be.

The various descriptible logic blocks, modules and circuits described in connection with those disclosed herein are general purpose processors, digital signal processors (DSPs) designed to perform the functions described herein. , Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) or other programmable logic devices, discrete gates or transistor logic, discrete hardware components, or any combination thereof. The general purpose processor may be a microprocessor, but in the alternative, the processor may be any traditional processor, controller, microcontroller or state machine. Processors are also implemented as a combination of computing devices related to a DSP core, or any other configuration, such as a combination of DSP and microprocessor, multiple microprocessors, and one or more microprocessors. Can be done.

The steps of methods or algorithms described in connection with those disclosed herein may be embedded directly in hardware, or in a processor or a combination of the two. The software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disks, removable disks, CD-ROMs, or any other form of recording medium known in the art. A typical recording medium is coupled to the processor so that the processor can read information from the recording medium and write the information to the recording medium. Alternatively, the recording medium can be integrated into the processor. The processor and recording medium may reside in the ASIC. The ASIC can reside on the user terminal. Alternatively, the processor and recording medium may reside in discrete components within the user terminal.

The above description disclosed is provided so that any person skilled in the art can make or use the disclosed one. Various improvements to this disclosure will be readily apparent to those skilled in the art. Also, the general principles defined herein can be applied to other variations without departing from the disclosed intent or scope. Therefore, this disclosure is not intended to be limited to the examples described herein, but is in line with the broadest scope consistent with the principles and novel features disclosed herein.<u style="single"> Hereinafter, the inventions described in the claims at the time of filing the application of the present application will be added.</u><u style="single"> [1] Determine the time frequency resources that can be used for orthogonal frequency division multiplexing (OFDM) and exclude the traffic data transmitted by code division multiplexing (CDM) and the time frequency resources used for signaling, and use them for OFDM. With at least one processor that allocates the possible time frequency resources to at least one terminal,</u><u style="single"> With one memory coupled to at least one processor</u><u style="single"> A device equipped with.</u><u style="single"> [2] The apparatus according to the above [1], wherein the at least one processor divides the time frequency resource available for OFDM into multiple tiles and allocates the time frequency resources to at least one of the multiple tiles to at least one terminal.</u><u style="single"> [3] The device according to [2] above, wherein each tile corresponds to a block of time-frequency resources having a non-orthogonal shape.</u><u style="single"> [4] The apparatus according to [2] above, wherein the at least one processor divides the time frequency resource available for OFDM into at least two different non-orthogonal multiple tiles.</u><u style="single"> [5] The apparatus according to [4] above, wherein the two different non-orthogonal shapes have mirror symmetry.</u><u style="single"> [6] The device according to [5] above, wherein the two different non-orthogonal shapes having mirror symmetry are associated with a mirror symmetric pilot pattern.</u><u style="single"> [7] The apparatus according to the above [2], wherein the at least one processor processes an OFDM symbol based on the OFDM symbol numerology for each tile assigned to the at least one terminal.</u><u style="single"> [8] Each tile has a first part of the time frequency resource defined based on the first OFDM symbol numerology and a second part of the time frequency defined based on the second OFDM symbol numerology. The device according to the above [2].</u><u style="single"> [9] Each tile further contains a third portion of the time frequency defined based on the first OFDM symbol numerology, the second portion being placed between the first and third portions. , The apparatus according to the above [8].</u><u style="single"> [10] The apparatus according to the above [1], wherein the at least one processor allocates different ones of the multiple tiles to each terminal overtime to achieve frequency hopping.</u><u style="single"> [11] The apparatus according to the above [1], wherein the at least one processor selects a pilot pattern for each terminal from the multiple pilot patterns.</u><u style="single"> [12] In [11], the multiple pilot pattern supports at least two different delay spreads, and the at least one processor selects the pilot pattern for each terminal based on the expected delay spread for the terminal. The device described.</u><u style="single"> [13] The multiple pilot pattern supports at least two different spatial ranks, and the at least one processor selects the pilot pattern for each terminal based on the spatial rank for the terminal, according to [11]. The device described.</u><u style="single"> [14] Each of the multiple pilot patterns has a multiple cluster of pilot tones arranged across tiles corresponding to blocks of time frequency resources, and each pilot tone has one symbol period used by the pilot. The device according to [11] above, which corresponds to one subcarrier of.</u><u style="single"> [15] The device according to [14] above, wherein the multiple clusters of the pilot tones for each pilot tone are located at at least two frequency positions across the tile.</u><u style="single"> [16] The device according to [14] above, wherein the multiple clusters of the pilot tones for each pilot pattern are located at at least two time positions across the tile.</u><u style="single"> [17] The device according to [1] above, wherein the at least one processor transmits a common pilot across the time frequency resources available for OFDM.</u><u style="single"> [18] The at least one processor sends data to each terminal in the at least one tile assigned to the terminal, and each in the at least one tile based on a pilot pattern selected for the terminal. The device according to [2] above, which transmits a pilot to the terminal of.</u><u style="single"> [19] The at least one processor receives data from each terminal in the at least one tile assigned to the terminal, and from each terminal, a pilot selected for the terminal in the at least one tile. The device according to [2] above, which receives a pilot based on a pattern.</u><u style="single"> [20] Determining time frequency resources that are available for Orthogonal Frequency Division Multiplexing (OFDM) and exclude time frequencies used for traffic data and signaling transmitted by Code Division Multiplexing (CDM), and</u><u style="single"> Allocate the time frequency resources available for OFDM to at least one terminal</u><u style="single">When</u><u style="single"> How to prepare.</u><u style="single"> [21] Allocating the available time-frequency resources to OFDM is</u><u style="single"> Dividing the time-frequency resources available for OFDM into multiple tiles, and</u><u style="single"> Assigning at least one said multiple tile to said at least one terminal</u><u style="single"> The method according to the above [20].</u><u style="single"> [22] The method according to [21] above, further comprising processing an OFDM symbol based on multiple OFDM symbol numerology for each tile assigned to at least one terminal.</u><u style="single"> [23] The method according to [20] above, further comprising selecting a pilot pattern from multiple pilot patterns.</u><u style="single"> [24] A means for determining time frequency resources that can be used for orthogonal frequency division multiplexing (OFDM) and exclude time frequency resources used for traffic data and signaling transmitted by code division multiplexing (CDM).</u><u style="single"> A means of allocating the time frequency resources available for OFDM to at least one terminal,</u><u style="single"> A device equipped with.</u><u style="single"> [25] The means of allocating the time frequency resources available to OFDM</u><u style="single"> The time-frequency resources available for OFDM are divided into multiple tiles, and each tile has a means corresponding to a block of time-frequency resources.</u><u style="single"> As a means of assigning at least one of the multiple tiles to each of the at least one terminal</u><u style="single"> The apparatus according to the above [24].</u><u style="single"> [26] A means for processing an OFDM symbol based on multiple OFDM symbol numerology for each tile assigned to at least one terminal.</u><u style="single"> The apparatus according to the above [25].</u><u style="single"> [27] Means for selecting a pilot pattern for each terminal from multiple pilot patterns</u><u style="single"> The apparatus according to the above [24].</u><u style="single"> [28] Determine the time frequency resources that can be used for Orthogonal Frequency Division Multiplexing (OFDM) and exclude the time frequency resources used for traffic data and signaling transmitted by Code Division Multiplexing (CDM).</u><u style="single"> Allocate the time frequency resources available for OFDM to at least one terminal</u><u style="single"> A recording medium that can be read by the processor that stores the instructions.</u><u style="single"> [29] The processor-readable recording medium according to the above [28], which further stores an instruction for selecting a pilot pattern for each terminal from the multiple pilot patterns.</u><u style="single"> [30] Time-frequency resources selected from the time-frequency resources available for orthogonal frequency-division multiplexing (OFDM) and excluding time-frequency resources used for traffic data and signaling transmitted by code-division multiplexing (CDM). With at least one processor that receives the allocation and exchanges data over the time frequency resources in the allocation.</u><u style="single"> With one memory coupled to at least one processor</u><u style="single"> A device equipped with.</u><u style="single"> [31] The device according to [30] above, wherein the allocation is made for a block of time frequency resources having a non-orthogonal shape.</u><u style="single"> [32] The apparatus according to [30], wherein the at least one processor processes an OFDM symbol based on multiple OFDM symbol numerology and exchanges data via the time frequency resource in the allocation.</u><u style="single"> [33] The apparatus according to [30], wherein the at least one processor processes a pilot symbol based on a pilot pattern selected from multiple pilot patterns.</u><u style="single"> [34] The pilot pattern has multiple clusters of pilot tones arranged across tiles corresponding to the time frequency resource in the allocation.</u><u style="single"> Here, the at least one processor transmits at least one pilot symbol from at least one antenna, with at least one pilot tone for each of the multiple clusters, and one pilot symbol from each antenna in each cluster. belongs to,</u><u style="single"> The device according to the above [33].</u><u style="single"> [35] The pilot pattern has multiple clusters of pilot tones arranged across tiles corresponding to the time frequency resource in the allocation.</u><u style="single"> Here, the at least one processor transmits at least one pilot symbol for at least one data stream in each of the multiple clusters, and each pilot symbol (whether it has already been published or not) is clustered with a quadrature code. Spread across all pilot tones of</u><u style="single"> The device according to the above [33].</u><u style="single"> [36] Of the time frequency resources selected from the time frequency resources available for orthogonal frequency division multiplexing (OFDM) and excluding the time frequency resources used for traffic data and signaling transmitted by code division multiplexing (CDM). Receiving quotas and</u><u style="single"> Exchanging data via said time frequency resources in said allocation</u><u style="single"> How to prepare.</u><u style="single"> [37] Exchanging the data</u><u style="single"> The method according to [36] above, comprising processing an OFDM symbol based on multiple OFDM symbol numerology and exchanging data via the time frequency resource in the allocation.</u><u style="single"> [38] In addition</u><u style="single"> The method according to [36] above, comprising processing a pilot symbol based on a pilot pattern selected from multiple pilot patterns.</u><u style="single"> [39] Time-frequency resources selected from the time-frequency resources available for Orthogonal Frequency Division Multiplexing (OFDM) and excluding the time-frequency resources used for trafficking data and signaling used in Code-Division Multiplexing (CDM). Means of receiving quotas and</u><u style="single"> With means for exchanging data via said time frequency resources in said allocation</u><u style="single"> A device equipped with.</u><u style="single"> [40] The means for exchanging the data is</u><u style="single"> Multiple OFDM Symbols A means of processing OFDM symbols based on numerology and exchanging data via said time frequency resources in said allocation.</u><u style="single"> The apparatus according to the above [39].</u><u style="single"> [41] Furthermore</u><u style="single"> The apparatus according to the above [39], comprising means for processing a pilot symbol based on a pilot pattern selected from multiple pilot patterns.</u>

<figref num="1">The figure which shows the wireless communication system.</figref><figref num="2">The figure which shows the slot structure of high-rate packet data (HRPD).</figref><figref num="3">The figure which shows the slot structure which supports OFDM and CDM in HRPD.</figref><figref num="4">The figure which shows the slot structure which supports OFDM and CDM of a single HRPD carrier in a 5MHz spectrum arrangement.</figref><figref num="5A">The figure which shows the tile structure which has the non-orthogonal tile.</figref><figref num="5B">The figure which shows the tile structure which has the non-orthogonal tile.</figref><figref num="6A">The figure which shows the pilot pattern about the tile in FIG. 5 and FIG.</figref><figref num="6B">The figure which shows the pilot pattern about the tile in FIG. 5 and FIG.</figref><figref num="6C">The figure which shows the pilot pattern about the tile in FIG. 5 and FIG.</figref><figref num="6D">The figure which shows the pilot pattern about the tile in FIG. 5 and FIG.</figref><figref num="6E">The figure which shows the pilot pattern about the tile in FIG. 5 and FIG.</figref><figref num="6F">The figure which shows the pilot pattern about the tile in FIG. 5 and FIG.</figref><figref num="6G">The figure which shows the pilot pattern about the tile in FIG. 5 and FIG.</figref><figref num="7">The figure for demonstrating the frequency hopping of one HRPD carrier.</figref><figref num="8">The figure which shows the process executed by the access point about communication.</figref><figref num="9">The figure which shows the process executed by a terminal about communication.</figref><figref num="10">The figure which shows the block diagram of an access point and a terminal.</figref>