Method and apparatus for forward link gain control in a power controlled repeater

Method and device for forward link gain control in power controlled repeater

Related Fields of Application The present invention generally relates to wireless communication systems, and more particularly, to a method and apparatus for controlling the forward link gain in a power-controlled repeater.

Background In a wireless wireless telephone communication system, many users communicate through a wireless channel. The use of code division multiple access (CDMA) modulation technology is one of several technologies that facilitate communication in which a large number of system users exist. Other multiple access communication system technologies, such as time division multiple access (TDMA) and frequency division multiple access (FDMA), are well known in the art. However, the spread spectrum modulation technology of CDMA has significant advantages over these modulation technologies used in multiple access communication systems.

CDMA technology has many advantages. An exemplary CDMA system is described in US Patent No. 4,901,307, which is entitled "Spread Spectrum Multiple Access Communication System Using Satellite Or Terrestrial Repeaters", published on February 13, 1990, and assigned to the assignee of the present invention And is incorporated here by reference. An exemplary CDMA system is further described in U.S. Patent No. 5,103,459, which is entitled "System And Method For Generating SignalWaveforms In A CDMA Cellular Telephone System", published on April 7, 1992, and assigned to the recipient of the present invention. Let the people and be incorporated here by reference.

In a typical system, several base stations are used to allow multiple mobile users to communicate with the base station as they move. The communication network will generally include a base station controller or similar device, which communicates with multiple base stations. Examples of communication networks include public switched networks, wireless networks, satellite networks, long-distance telephone networks, local telephone networks, and the Internet.

Use repeaters to extend the range of the base station. The repeater receives wireless signals from the base station and one or more mobile users. The repeater amplifies the received signal and transmits a wireless signal to the base station and/or to the mobile station based on the amplified signal. As a result, the repeater extends the range of the base station. The base station generally also receives wireless signals directly (that is, without using a repeater) from other mobile stations.

Repeaters provide communication companies and service providers with a cost-effective way to fill holes in the coverage area or expand the coverage area. However, the use of repeaters is hindered by daily and seasonal changes in the environment, which cause fluctuations in the gain of the repeater and fluctuations in the path loss between the repeater and the base station. These fluctuations can adversely affect the coverage area and the service within the coverage area of the repeater. Therefore, it is necessary to control the gain of the repeater to stabilize the coverage area of the repeater.

Brief Description of the Drawings Fig. 1 is a schematic diagram of a spread spectrum communication system supporting multiple users.

Figure 2 is a block diagram of a base station and a mobile station in a communication system.

Figure 3 is a block diagram illustrating the forward link and the reverse link between the base station and the mobile station.

Figure 4 is a block diagram illustrating the use of a repeater in combination with a base station and a mobile station.

Figure 5 is a block diagram of an embodiment of a repeater with an embedded subscriber unit.

Figure 6 illustrates a block diagram of specific components in an embodiment of a subscriber unit.

Fig. 7 is a block diagram illustrating an embodiment of a power controlled repeater for the forward link and the reverse link.

Fig. 8 is a flowchart of an embodiment of a method for using a power controlled repeater.

FIG. 9 is a flowchart of a method of controlling the forward link gain of a repeater by using an embedded subscriber unit.

Fig. 10 is a flowchart of another method of controlling the forward link gain of a repeater by using an embedded subscriber unit.

Fig. 11 is a flowchart of another method for controlling the forward link gain of the repeater by using an embedded subscriber unit.

The detailed description specifically uses the word "exemplary" to mean "serving as an example, instance, or illustration." Any embodiment described herein as "exemplary" need not be regarded as more preferred or advantageous than other embodiments. Although various aspects of the present invention are shown in the drawings, unless otherwise specified, the drawings are not drawn to scale.

The following discussion illustrates a method and apparatus for controlling the forward link gain in a power controlled repeater. First, an exemplary spread spectrum wireless communication system is introduced. The details about base stations, mobile stations and the electrical communication between them are presented. Explains the use of repeaters to extend the coverage area of the base station. Several block diagrams and flowcharts illustrate the details of using the embedded subscriber unit in the repeater for forward link gain control. A typical embodiment of the subscriber unit is also discussed.

The exemplary embodiment adopts a spread spectrum wireless communication system. Wireless communication systems are widely used to provide various types of communication, such as voice, data, and so on. These systems can be based on CDMA, TDMA, or some other modulation technique. CDMA systems provide specific advantages over other types of systems, including increased system capacity. CDMA systems send and receive wireless signals in a single frequency band, and use coding to separate individual signals. In contrast, other systems use frequency and time diversity to separate individual signals. The CDMA system has shown clear advantages in the areas of capacity, voice quality, confidentiality, and cell handover.

The system can be designed to support one or more standards, such as "TIA/EIA/IS-95-B MobileStation-Base Station Compatibility Standard for Dual-Mode Wideband SpreadSpectrum Cellular System", here called IS-95 standard, by name It is a standard proposed by the association of the "3rd Generation Partnership Project" (herein referred to as 3GPP) and included in a set of documents including document numbers 3G TS 25.211, 3G TS 25.212, 3G TS 25.213, and 3G TS 25.214, and The standard proposed by the association named "3rd Generation Partnership Project 2" (herein referred to as 3GPP2) and included in the document number 3G TS 25.302, and TR-45.5 formerly known as IS-2000MC, referred to here as It is the cdma2000 standard. The standards cited above are specifically incorporated herein by reference.

Each standard specifically defines the processing of data transmitted from the base station to the mobile station, and vice versa. As an exemplary embodiment, the following discussion considers a spread spectrum communication system that complies with the cdma2000 protocol standard. Other embodiments can be combined with another standard.

FIG. 1 is an example of a communication system 100. The system 100 supports multiple users and can implement at least aspects of the embodiments discussed herein. Any of a variety of algorithms and methods can be used to schedule transmissions in the system 100. The system 100 provides communication for multiple cells 102A-102G, and each cell is respectively served by a corresponding base station 104A-104G. In an exemplary embodiment, some base stations 104 have multiple receiving antennas, while other base stations 104 have only one receiving antenna. Similarly, some base stations 104 have multiple transmit antennas, while other base stations 104 have only a single transmit antenna. There are no restrictions on the combination of transmitting antennas and receiving antennas. Therefore, the base station 104 may have multiple transmitting antennas and a single receiving antenna, or multiple receiving antennas and a single transmitting antenna, or a single transmitting and receiving antenna or multiple transmitting and receiving antennas at the same time.

The terminals 106 in the coverage area may be fixed (ie, stationary) or mobile. As shown in FIG. 1, various terminals 106 are distributed throughout the system. Each terminal 106 communicates with at least one and possibly multiple base stations 104 on the forward and reverse links at any given moment, depending on whether soft handover is used, or whether the terminal is designed and operated for example. To receive multiple transmissions from multiple base stations (concurrently or sequentially). Soft handoffs in CDMA communication systems are well known in the art and are described in detail in U.S. Patent No. 5,101,501, which is entitled "Method and system for providing a Soft Handoff in a CDMA CellularTelephone System" and is assigned to the present invention. Assignee.

The forward link refers to the transmission from the base station 104 to the terminal 106, and the reverse link refers to the transmission from the terminal 106 to the base station 104. In an exemplary embodiment, some terminals 106 have multiple receiving antennas, while others have only one receiving antenna. In FIG. 1, base station 104A sends data to terminals 106A and 106J on the downlink, base station 104B sends data to terminals 106B and 106J, base station 104C sends data to terminal 106C, and so on.

FIG. 2 is a block diagram of the base station 202 and the mobile station 204 in the communication system. The base station 202 performs wireless communication with the mobile station 204. As described above, the base station 202 transmits a signal to the mobile station 204 that receives the signal. In addition, the mobile station 204 can also transmit signals to the base station 202.

3 is a block diagram illustrating base station 202 and mobile station 204 of forward link 302 and reverse link 304. As mentioned above, the forward link 302 refers to the transmission from the base station 202 to the mobile station 204. The forward link 302 is sometimes also referred to as the downlink. The reverse link 304 refers to the transmission from the base station 204 to the mobile station 202. The reverse link 304 is also sometimes referred to as the uplink.

As described with reference to FIG. 4, the repeater may be used with the base station 202 and the mobile station 204. The repeater extends the range of the base station 202 by amplifying and retransmitting wireless signals between the mobile station 204 and the base station 202. Related issues such as multipath and fading are discussed below. After the discussion, Figure 4 will introduce the repeater.

Multipath signals are different forms of the same wireless signal generated by reflections from various structures and natural components. Multipath signals will have a phase shift that causes the signals to cancel each other out at specific locations. The signal loss caused by the phase cancellation of the multipath signal is called fading. Fading is a serious problem in wireless systems because it disrupts user communications. For example, several multipath copies of a single wireless signal transmitted by a wireless communication device may be generated by reflections from trees and buildings. These multipath copies are combined in the repeater or mobile station 204 and cancel each other due to phase shift.

Unlike other wireless systems, CDMA systems can handle multipath signals to provide additional diversity. Unfortunately, multipath signals that are not separated by a sufficient time delay can still cause fading in the CDMA system. The signal power is generally increased to overcome fading, but the increased signal power reduces the range of the system.

In a typical system, several base stations 202 are used to allow multiple mobile stations 204 to communicate with the base station 202 while moving. The communication network 100 generally includes a base station controller (not shown) or similar equipment that exchanges communications with a plurality of base stations 202. Examples of the communication network 100 include a public switching network, a wireless network, a satellite network, a long-distance telephone network, a local telephone network, and the Internet.

FIG. 4 is a block diagram of the use of the repeater 401 with the base station 202 and the mobile station 204. The wireless repeater 402 is sometimes used between the mobile station 204 and the base station 202. The repeater 402 expands the range of the base station 202 by amplifying and retransmitting wireless signals between the mobile station 204 and the base station 202. Although not shown, the base station 202 generally does not use the repeater 401 and receives wireless signals from other mobile stations 204.

The repeater 401 provides a cost-effective way for communication companies and service providers to fill holes in the coverage area or expand the coverage area. However, the use of the repeater 401 is hindered by daily and seasonal changes in the environment, which cause fluctuations in the gain of the repeater 401 and fluctuations in the path loss between the repeater 401 and the base station 202. These fluctuations can adversely affect the coverage area and the service within the coverage area of the repeater 401.

Referring now to FIG. 5, it is desirable to control the forward link gain of the repeater 401 to stabilize the repeater coverage area. This can be done by embedding the subscriber unit 501 within the repeater 401 and injecting the forward link 402 of the repeater 401 into the forward link 502 of the embedded subscriber unit 501.

The embedded subscriber unit 501 can overcome the fluctuations described above. In addition, there is a more consistent coverage area and service for the mobile stations 204 in the coverage area of the repeater 401.

The use of the power controlled repeater 401 is similar to the use of a conventional repeater. An additional step is the need for the embedded subscriber unit 501 to establish a reference forward link power level to accompany the nominal repeater gain and the nominal repeater forward link gain. The reference forward link power level may include a reference received power level 518, a reference received Ec/Io level 522, and/or a reference transmit power level 508.

In order to maintain a consistent coverage area and service for the mobile station 204 in the coverage area of the repeater 401, it is desirable to maintain the pilot signal sent from the base station 202 at a constant level at the output of the repeater 401. This is the forward link pilot output power level 514. In the repeater 401, the forward link gain 516 of the repeater 401 is set to achieve the desired pilot forward link output power level 514. If the forward link gain 516 or forward link path loss 512 of the repeater 401 seen between the base station 202 and the repeater 401 changes, the desired pilot output power 514 also changes, causing the repeater Undesirable shrinkage or growth of the area covered by the filter 401. The embodiments herein provide a way to measure the forward link path loss 512 plus the forward link repeater gain 516, and use this information to maintain a stable forward link pilot output power 514.

One way to use the subscriber unit 501 of the links 402, 404 embedded in the repeater 401 to maintain the forward link pilot output power level 514 of the repeater 401 is by measuring two parameters and averaging:( 1) The total in-band power it receives, called the received power level 510, and (2) the received Ec/Io level 520. These two parameters can be added together to produce a single forward link reference that is used to maintain the forward link pilot output power level 514 of the repeater 401. Any change in this reference indicates a change in the forward link gain 516 or forward link path loss 512 of the repeater.

As described above, the subscriber unit 501 is embedded in the repeater 401, and its links 502, 504 are integrated into the repeater links 402, 404. The received power level 510 and the received Ec/Io level 520 can be used to measure the forward link path loss 512 and the forward link repeater gain 516 seen between the base station 202 and the repeater 401. The subscriber unit 501 averages the received power level 510 and the received Ec/Io level 520 to eliminate the fading effect, leaving path loss and forward link gain information. This path loss information 512 and gain information 516 can be used to set and maintain the forward link pilot output power 514 of the repeater 401. Similarly, the subscriber unit 501 can be put into traffic, and its transmit power level 506 can be used to measure the path loss seen between the repeater 401 and the base station 202.

The reference power level can be saved to modify the forward link pilot output power level 514. The current received power level 510 can be saved as a reference received power level 518. The current transmission power level 506 can be saved as a reference transmission power level 508. The current received Ec/Io level 520 can be saved as the reference Ec/Io level 522. Any combination of the received power level 510 and/or the transmit power level 506 and/or the Ec/Io level 520 may be saved in the reference levels 518, 508, 522 and re-measured later. The re-measured value can be compared with the saved value in order to check again the path loss or the change in the forward link repeater gain. The forward link gain of the mobile repeater 401 then compensates the repeater 401 and returns the repeater 401 to its desired forward link pilot output power 514.

One embodiment of the subscriber unit 501 is shown in the system 600 illustrated in the functional block diagram of FIG. 6. The system 600 includes a central processing unit (CPU) 602 that controls the operation of the system 600. The memory 604 may include a read only memory (ROM) and a random access memory (RAM), and the memory 604 provides instructions and data to the CPI 602. A part of the memory 604 may also include non-volatile random access memory (NVRAM).

The system 600 is generally embedded in a wireless communication device such as a cell phone. The system 600 also includes a housing 606, which contains a transmitter 608 and a receiver 610 that allow data transmission and reception between the system 600 and remote stations, such as cell site controlDevice or base station 202. The transmitter 608 and the receiver 610 can be combined into a transceiver 612. The antenna 614 is attached to the housing 606 and is electrically coupled to the transceiver 612. The operations of the transmitter 608, the receiver 610, and the antenna 614 are well known in the art and need not be described here.

The system 600 also includes a signal detector 616 for detecting and quantifying the signal level received by the transceiver 612. The signal detector 616 detects signals such as total energy, pilot energy per pseudonoise (PN) chip, power spectral density, and other signals, as known in the art. The signal detector 616 calculates various indicators and values for use in the system 600, as described in further detail below.

A set of timers 618 work in conjunction with the pilot strength processor 620, the pilot received power processor 622, and the total received power processor 624. By measuring the received signal levels and processing these signals, the system 600 can determine the quality of the communication channel between the wireless communication device and its base station 202.

The pilot strength processor 620 receives the pilot strength indicator (Ec/Io) from the signal detector 616. The signal detector 616 divides the pilot energy ratio (Ec) per PN chip by the total power spectral density (Io) received at the transceiver 612. The ratio of this pilot energy to the total received energy is called "pilot strength", as is well known in the art. It is also known in the art that the pilot strength depends on the load conditions of the active cell and neighboring cells, and therefore is an indication of the traffic load in a specific cell.

The total received power processor 624 uses a variable Rx, which is detected and quantified at the signal detector 616. The total received power (Rx) is a measure of the total power received at the transceiver 612. It includes thermal noise, interference from other callers, and the pilot signal sent to that particular transceiver 612. The sum of all this received energy is stored to indicate the total received power.

The pilot received power processor 622 receives a received signal strength indicator (RSSI) from the signal detector 616. RSSI indicates the pilot received power, and in an exemplary embodiment, it is calculated by adding (Ec/Io) to the total received power (Rx), which is well known in the art. RSSI is independent of system load, and changes in RSSI indicate changes in forward link path loss. These path loss changes are important in determining when to switch services, as detailed below.

The state changer 626 of the system 600 controls the state of the wireless communication device according to the current state and the additional signal received by the transceiver 612 and detected by the signal detector 616. The wireless communication device can work in any of multiple states.

The system 600 also includes a system determiner 628 for controlling the wireless communication device and determining which service provider system the wireless communication device should transmit to when it determines that the current service provider system is insufficient.

The components of the system 600 are coupled together by a bus system 630. In addition to the data bus, the bus system 630 may include a power bus, a control signal bus, and a status signal bus. However, for brevity, various buses are illustrated as the bus system 630 in FIG. 6. Those skilled in the art will understand that the system shown in FIG. 6 is a functional block diagram rather than a list of specific components. For example, although the pilot strength processor 620, the pilot received power processor 622, and the total received power processor 624 are illustrated as three separate blocks within the system 600, they may actually be embodied in one physical component, such as digital Signal processor (DSP). They can also reside in the memory 604 as program codes and be operated on by the CPU 602. The same considerations also apply to the other components listed in the system 600 of FIG. 6.

The power adjustment command compensates for the time-varying path loss in the wireless channel. The path loss in the wireless channel is defined as the degradation or loss experienced by the signal as it is transmitted between the subscriber unit 501 and the base station 202. Path loss is characterized by two independent phenomena: average path loss and fading. In a typical wireless system, the forward link and the reverse link operate on different frequencies. However, since the forward link and the reverse link operate in the same frequency band, there is a significant correlation between the average path loss of the two links. On the other hand, fading is an independent phenomenon for the forward link and the reverse link, and changes rapidly over time, especially when the remote unit is in motion or near a moving object.

In an exemplary wireless system, each subscriber unit 501 estimates the path loss of the forward link based on the total power at the input of the remote unit. The total power is the sum of the power observed by the subscriber unit 501 from all base stations 202 operating on the same frequency allocation. The subscriber unit 501 sets the nominal transmission power level of the reverse link signal from the estimate of the average forward link path loss.

As described above, each base station 202 with which the subscriber unit 501 establishes communication sends a power adjustment command to the subscriber unit 501 in order to compensate for the difference between the path loss on the forward link and the path loss on the reverse link, to compensate for fading, And to compensate for other sources of error. In this way, the subscriber unit 501 creates a reverse link transmission gain adjustment signal that increases or decreases the reverse link transmission power level above or above the nominal level determined by estimating the average forward link path loss. the following. The value of the transmission gain adjustment signal is the cumulative effect of the power control adjustment commands received from the base station 202 over a period of time. If the subscriber unit 501 receives an equal number of up and down commands, the value of the transmission gain adjustment signal is zero, and the reverse link transmission level is equal to the nominal value. If the subscriber unit 501 receives more up-regulation commands than down-regulation commands, the value of the transmission gain adjustment signal is logically positive, and the reverse link transmission level is greater than the nominal value. If the remote unit receives more down commands than up commands, the value of the transmitted gain adjustment signal is logically negative, and the reverse link transmission level is less than the nominal value.

Generally, the use of the repeater 401 in a CDMA network is desirable for service providers due to hole filling or due to the expansion of the coverage area of a given sector. Hole filling means providing capacity in previously uncovered areas. A hallmark of the hole filling application is that the area is generally surrounded by a coverage area, usually surrounded by a sector that also communicates with the repeater 401. Enlarging or moving the coverage area of a sector refers to shifting the location or shape of the coverage area from one sector. An example of this latter application might be to provide highway coverage. Assuming that two sectors cover the highway adjacent to the base station 202, a repeater 401 may be considered to provide coverage from the location of the base station 202 outside the immediately visible area.

However, as described above, the performance of the repeater 401 may be degraded due to its forward link pilot output power level 514 deviating from its operating point. In particular, the repeater 401 is affected by multiple factors, including temperature changes during the day, temperature changes from one season to another, attenuation due to leaves in spring and summer, and/or along the base station-repeater New obstacles erected by the link.

The above phenomenon may adversely affect the coverage area and the service within the coverage area of the repeater 401. Therefore, it is desirable to be able to detect and quantify the change, and restore the pilot output power of the repeater 401 to a predetermined level. As described here, this can be done by embedding the subscriber unit 501 in the repeater 401.

FIG. 7 shows a block diagram of an embodiment of a power controlled repeater 401. As shown in Figure 7, the forward and reverse links of the embedded subscriber unit 501 are the same as the forward and reverse links of the repeater 401, and in addition, the forward and reverse links of the embedded subscriber unit 501 The link signal will experience the same gain fluctuations as the repeater 401. Those skilled in the art will understand that various changes can be made to the block diagram of FIG. 7 to implement various other embodiments. For example, the subscriber unit 501 may only be inserted into the forward link, instead of being inserted into both the forward and reverse links.

The requirements for the output of the forward link power amplifier are mainly driven by the size of the desired coverage area, and this requirement is generally expressed by the maximum average power WR. However, since the instantaneous power on the forward link of the repeater 401 is substantially higher than WR, the requirements for the output of the forward link power amplifier should be extended to the maximum instantaneous power to avoid saturation. In a CDMA network, The maximum instantaneous power and the maximum average power are related through the peak-to-average ratio.

When calculating the gain of the repeater 401, it is assumed that the forward link gain and the reverse link gain are the same. Also, WB is defined as the power amplifier output of the base station 202 (typical value is 25W). WR is defined as the forward link power amplifier output of the repeater 401. From the target forward link power amplifier output WR, the base station-repeater link gain (GT) can be calculated as shown in Equation 1.

GT=WRWB]]> Formula 1 The gain of the repeater 401 can be calculated as shown in Formula 2. GT is the base station-repeater link gain. Gd is the gain of the repeater donor antenna. Lp is the target path loss between the repeater donor antenna and the base station antenna.

Ga is the antenna gain of the base station antenna.

GR=GTGdLpGa=WRWB1GdLpGa]]> Formula 2 Referring to Fig. 7, in dB, the forward link gain of the power controlled repeater will be decomposed into the form shown in Formula 3. In Equation 3, CL is the loss of the coupler 708, and DL is the loss of the multiplexer 710.

GR=G1+G2+CL+2DL Formula 3 is important when selecting G1 712, the forward link coupler 708 to the embedded subscriber unit 501, and the forward link attenuator 714 ATT1 714 of the embedded subscriber unit It is to ensure that the embedded subscriber form 501 will receive a sufficient amount of forward link overhead channel power (pilot, paging, and synchronization). The typical minimum amount of forward link overhead channel power is -85dBm.

Since it is assumed that the forward link gain and the reverse link gain are the same, the reverse link gain of the power-controlled repeater is also GR. From Figure 7, in dB, it can be decomposed into formula 4 Show the form. In Equation 4, CL is the coupler 708, and DL is the antenna duplexer 710 loss.

GR=G3+G4+CL+2DL Formula 4 The embedded subscriber unit 501 can be used to adjust the G2 718 to control the forward link gain of the repeater. The microprocessor 706 can be used to control various parameters and components of the repeater 401. In theory, changing G2 718 will change the nominal noise factor of repeater 401. However, this analysis assumes that the nominal noise factor of repeater 401 is constant and can be made substantially constant by allocating sufficient gain in G1 712.

In particular, from the expected change of G2 718 (each embedded subscriber unit 501), and from the expected noise factor of G2 718, it can be calculated that the change in the nominal noise factor of the repeater 401 is less than a certain predetermined amount, How much dB should G1 712 exceed the nominal G2 718?

For example, if G2 718 is expected to change by 10dB, it can be concluded from the expected noise factor of G2 718 that in order to change the nominal noise factor of repeater 401 by less than 1%, G1 712 should exceed the nominal G2 71840dB. The constraints shown in Equation 5. Combining the formulas shown in Equations 3 and 5 provides the formula shown in Equation 6. CL is the coupler 708 loss. DL is the antenna duplexer loss. Once G2 718 is determined, G1 712 can be obtained from Equation 5.

G1=G2+10dB+40dB=G2+50dB Formula 5GR=(G2+50dB)+G2+CL+2DL Formula 6G2=0.5(GR-CL-2DL-50dB) Formula 7 For the embedded subscriber unit 501, it The gain of the forward link path in the repeater 401 should be equal to the gain of its reverse link path in the repeater 401. In particular, the reverse link attenuator 716 and ATT2 716 of the embedded subscriber unit should be set in such a way that the equation in Equation 8 holds. In Equation 8, CL is the coupler loss.

G1+G2+CL+ATT1=ATT2+CL+G3+G4 Formula 8 The use of a repeater combined with forward link gain control is very similar to the use of a conventional repeater, except that embedded subscribers are added in the repeater Unit to establish the forward link outside of the reference. This benchmark will include the sum of the received power and received Ec/Io level and/or transmit power of the embedded subscriber unit. When a repeater is used, the steps shown in Figure 8 are performed. In step 802, the forward link gain of the repeater 401 is adjusted to achieve the target forward link pilot power amplifier output. Then, in step 804, the reverse link gain of the repeater is adjusted to balance the forward link and the reverse link. Finally, in step 806, the forward link reference power of the embedded subscriber unit is established.

Regarding the step 802 of adjusting the forward link gain, the target repeater forward link pilot power amplifier output WR is driven by the size of the desired coverage area. To satisfy WR, adjust the gain G2 718.

With the setting of the forward link gain of the power-controlled repeater 401, the next step is step 804: balance the forward link and the reverse link in the coverage area of the base station 202 and the repeater 401. To accomplish this task, the gain G4 704 can be adjusted.

FIG. 9 is a flowchart illustrating a method 900 of controlling forward link gain by using an embedded subscriber unit 501. First, in step 902, the received power and the received Ec/Io are obtained. Then, in step 904, this received power and received Ec/Io level are used to measure the forward link path loss and forward link repeater gain. In step 906, the received power and the received Ec/Io can be averaged to minimize the fading effect. Then, in step 908, the path loss and forward link repeater gain information can be used to set and maintain the forward link repeater output power.

FIG. 10 is a flowchart of another method 1000 for controlling the forward link gain by using the embedded subscriber unit 501. First, put the embedded subscriber unit 501 into the traffic 1200. Then in step 1004, the embodiment of FIG. 10 waits for the closed loop power control to be fixed. Once in the traffic mode, the transmit power level of the subscriber unit 501 is obtained in step 1006. In step 1008, the transmit power level can be used to measure the forward link path loss between the repeater 401 and the base station 202. Then, in step 1010, the path loss information is used to set and maintain the forward link gain output power.

FIG. 11 is a flowchart of another method 1100 for controlling the forward link gain by using the embedded subscriber unit 501. In this method, transmit power level or receive power level or receive Ec/Io level can be used. First, in step 1102, the reference power level is saved. The saved reference power level is either the current transmit power level and/or the current received power level and/or the received Ec/Io level. The method waits for a period of time at step 1104 until it measures the current power level again. When the current power level is measured in step 1106, the current power level can be compared with the reference power level in step 1108 to check the forward link path loss or the change in forward link repeater gain. Then in step 1110, the path loss information is used to modify the forward link gain output power as needed. The method shown in Figure 11 can be iterated to continue monitoring the power level.

In short, the repeater will allow communication companies or service providers to fill holes in the coverage area or expand the coverage area. However, the use of repeaters is hindered by the environment and fluctuations within the repeater gain. These fluctuations can adversely affect the coverage area and the service within the coverage area of the repeater.

From the above problems, it is desirable to maintain a constant forward link pilot output power of the repeater. This goal can be met by embedding a subscriber unit in the repeater and by inserting the link of the embedded subscriber unit into the link of the repeater. With a common forward link and reverse link, the embedded subscriber unit can be used to calibrate the gain of the repeater.

During the installation of the repeater with forward link gain control, the presence of the embedded subscriber unit allows the establishment of a forward link reference to accompany the nominal repeater forward link path loss and gain. After the installation is complete, the embedded subscriber unit can perform periodic calibration. Any deviation from the forward link reference will indicate a change in the forward link gain or path loss of the repeater.

Those skilled in the art can understand that information and signals can be represented by any of a variety of different technologies and processes. For example, the data, instructions, commands, information, signals, bits, symbols, and chips that may be involved in the above description can be represented by voltage, current, electromagnetic waves, magnetic fields or their particles, light fields or their particles, or any combination thereof. .

Those skilled in the art can further understand that the various illustrative logical blocks, modules, and algorithm steps described in conjunction with the embodiments disclosed herein can be implemented as electronic hardware, computer software, or a combination of both. In order to clearly illustrate the interchangeability between hardware and software, various illustrative components, block diagrams, modules, circuits, and steps are generally described in accordance with their functionality. Whether these functionalities are implemented as hardware or software depends on the specific applications and design constraints adopted by the entire system. Technical personnel may implement the functions in different ways for each specific application, but such implementation decisions should not be construed as causing a departure from the scope of the present invention.

The implementation or execution of various illustrative logical blocks, modules, and algorithm steps described in conjunction with the embodiments described herein can be used: general purpose processors, digital signal processors (DSP), application specific integrated circuits (ASIC), field Programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination designed to perform the functions described herein. A general-purpose processor may be a microprocessor, however, in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented by a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors combined with a DSP core, or any other such configuration.

The steps of the method or algorithm described in conjunction with the embodiments disclosed herein may be directly included in the hardware, in the software module executed by the processor, or in both. The software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, removable disk, CD-ROM or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such that the processor can read information from the storage medium or write information to the storage medium. Alternatively, the storage medium can be integrated with the processor. The processor and storage medium may reside in the ASIC. The ASIC may reside in the user terminal. Alternatively, the processor and storage medium may reside as discrete components in the user terminal.

The above description of the preferred embodiments enables those skilled in the art to make or use the present invention. Various modifications of these embodiments are obvious to those skilled in the art, and the general principles defined here can be applied to other embodiments without using creative ability. Therefore, the present invention is not limited to the embodiments shown here, but should conform to the broadest scope consistent with the principles and novel features disclosed herein.