Method and apparatus for downlink power control in macro diversity radio systems

Field of the Invention The present invention generally relates to the field of communication systems having macrodiversity capability, and more particularly to the control of transmission power of one or more transmitters used to transmit information to a mobile station. Background of the Invention A simplified layout of the cellular communication system is depicted in Figure 1. Mobile stations M1 to M10 communicate with the fixed portion of the public switched telephone network (PSTN) by transmitting radio signals to cellular base stations B1 to B10 and receiving radio signals from cellular base stations B1 to B10. .. Cellular base stations B1 to B10 are sequentially connected to the PSTN via the mobile exchange center (MSC). Each base station B1 to B10 transmits a signal within the corresponding area or "cell" C1 to C10. Within each cell, the base station transmits information to the mobile unit via the downlink RF channel, while the mobile unit transmits information to the base station via the uplink RF channel. As depicted in Figure 1, the base station is ideally placed so that the cell covers most of the area where mobile phone communication normally takes place (eg, a metropolitan area) with minimal overlap. be able to. Cellular systems were originally designed to operate in a one-to-one correspondence between mobile stations and related base stations that cover geographic cells, while having more than one link. It has been clarified that the effects of shadowing and fading can be reduced by communicating the same signal to one mobile station via the system. For example, two different base stations can communicate the same information to one mobile station via two different spatial offset links. The mobile station processes these signals coming from the two links by combining these signals in some way (maximum ratio synthesis). This method is known as diversity. The conventional spatial diversity method requires two or more separate antennas in a single base station or two or more base stations in order to communicate with a mobile station. However, diversity is a base station or antenna (ie, multiple). It is not limited to the spatial offset of (number of transmission lines). Diversity transmission can be performed using one or more of the offsets in time, polarization, or frequency. An example of temporal diversity is interleaving, which is used in the IS-54B-EIA / TIA standard for North American digital cellular systems. Frequency diversity is achieved by transmitting the same information on two different frequencies, but such a scheme does not allow efficient use of the frequency spectrum. Briefly, as mentioned above, the concept of spatial diversity involves receiving signals through multiple signal paths. This method is referred to as macrodiversity because spatial diversity can include communication with mobile stations that utilize two completely different base stations. However, as used herein, the term macrodiversity refers to configurations in which the antennas used for diversity transmission are located close to each other or co-located within the same base station (co-). It is possible to include even the configuration that is located). Figures 2-5 depict some exemplary macrodiversity configurations. Figure 2 illustrates the macrodiversity configuration. In this configuration, the same message 206 is transmitted to the mobile station 208 by each of the first base station 202 and the second base station 204. The message 206 is transmitted to the mobile station 208 via different signal paths in the form of a first downlink 210 and a second downlink 212. The first and second downlink signals 210 and 212 are recombinated in the mobile station 208 to extract message 206. The mobile station 208 transmits to the base stations 202 and 204 via the first and second uplink transmission lines 214 and 216, respectively. Figure 3 illustrates the macrodiversity configuration. In this configuration, the same message 306 is broadcast from the first antenna 304 and the second antenna 305. Although the antennas 304 and 305 have different polarization characteristics (eg horizontal and vertical polarization) , Are located in the same base station 302. The first and second downlinks 310 and 312 communicate message 306 from base station 302 to mobile station 308, while the corresponding first and second uplinks 314 and 316 communicate from mobile station 308 to base station 302. I do. Figure 4 depicts a macrodiversity configuration for an indoor RF communication system. In this configuration, one or more of the first, second and third antennas 402, 404, 410 transmit a signal containing the same message 406 to the mobile unit 408. As depicted in the figure, the first and second downlinks 410 and 412 communicate message 406 from antennas 404 and 410 to mobile station 408, respectively. The first and second uplinks 414 and 416 communicate from the mobile station 408 to the antennas 404 and 410, respectively. Figure 5 depicts a single base station macrodiversity configuration. In this configuration, separate coverage areas are covered by each of the first and second directional lobes 518 and 520 generated by the antenna array 504. The first directional lobe 518 maintains the first macrodiversity link. This first macrodiversity link includes a first downlink 510 that carries message 506. The second directional lobe 520 maintains the second macrodiversity link. This second macrodiversity link includes a second downlink 512 containing message 506. The first and second uplinks 514 and 516 communicate from the mobile station 508 to the antenna array 504, respectively, within the range of the lobes 518 and 520, respectively. In a macrodiversity configuration, the base station and / or antenna communicates with a particular mobile station known as an "active set" component. For example, looking back at Figure 4, antennas 404 and 410 are considered components of the active set. The components of the active set move mobile stations in and out of the coverage area processed by the system's base stations and / or antennas. It may change as you do. As known to those skilled in the art, handoffs can be achieved by adding and / or removing base stations and / or antennas from the active set. Macrodiversity increases robustness, achieves improved downlink quality, and suppresses fading. However, due to the additional active transmission element of the macrodiversity scheme, the interference (ie, C / I ratio) of surrounding mobile stations and / or base stations operating in the vicinity increases. Traditional macrodiversity systems typically utilize the same amount of downlink that transmits power for each antenna in the active set. For example, the IS-95 system uses the same transmit power level for all downlinks in the active set. Careful consideration should be taken when adding or removing components from the active set to minimize interference on irrelevant links, as this can cause unwanted interference for other users. Therefore, one way to control interference is to limit the number of base stations and / or antennas in the active set. Another method used in conventional systems to reduce the effects of unnecessary interference resulting from macrodiversity operations is power split control. When performing power split control, the downlink transmit power can also be split evenly between each active base station and / or antenna in the active set. That is, if there are three downlinks and a total transmit power of P is available, then each of the downlinks will have a transmit power level of P / 3. However, when the "weakest" downlink in the active set is operating at P / 3 power levels, such allocations can also introduce an unnecessary amount of interference. In particular, this link may actually provide a small improvement in communication robustness, but in the end it causes even more undue interference and more disruption to surrounding communications. Will be. As a result, the C / I ratio of adjacent cells may be adversely affected and only the minimum gain of communication efficiency may be obtained. The DS-CDMA system utilizes a proportional downlink transmission power control method that allocates downlink transmission power according to the characteristics of the downlink signal received by the mobile station. In particular, a certain amount of transmit power used for downlink is defined based on the strength and interference value of the pilot channel signal of the downlink signal as measured by the mobile station. This measurement information is then reported to the system by the mobile station. This allows you to use a minimum amount of power to maintain the desired level of communication efficiency, while at the same time ensuring that minimal interference is introduced to adjacent unrelated links. Such a system is desirable. However, DS-CDMA systems have many drawbacks. For example, DS-CDMA systems require significant information costs and waste important resources to perform downlink power control. In DS-CDMA downlink power control systems, mobile stations are used to periodically measure the path gain characteristics of cells adjacent to the mobile station. Measurement reports are regularly replied with relevant uplinks. Due to the frequent use of so-called "fast" power control in DS-CDMA systems, the measurement and transfer of information requires the use of approximately 10% of the uplink frame capacity for downlink measurement information and reporting only. In some cases. As a result, less frame capacity is used for other information. The mobile station must perform additional processing to make the measurement, format the measurement information and transmit it. This has the effect of wasting processing resources, complicating the design and increasing handset power consumption. Therefore, there is a demand for a downlink transmission power control system for each antenna and / or base station downlink so as not to reduce the information capacity of the frame transmitted by the mobile station. Do not impose additional tasks on mobile stations such as downlink quality measurement and processing of transmission of measurement data It is even more desirable to provide a downlink power control system. Outline of the Invention In order to solve the above-mentioned problems, the present invention provides a power control system in which uplink signal quality is measured by a base station and downlink power control is performed by a macrodiversity system. The present invention is to save the mobile station from the need for special processing and sacrificing the uplink frame capacity for measurement information. As a result, it is possible to reduce manufacturing costs, design complexity, and power consumption associated with mobile stations while performing downlink power control. By either measuring the uplink according to an exemplary embodiment of the invention or utilizing an uplink quality coefficient already available in accordance with a system standard (such as GSM or D-AMPS). Uplink quality can be measured accurately. Within one or more base stations, this uplink quality information is used by the control means associated with the active set or the node connected to the base station to provide the downlink transmit power level. Such downlink transmit power control allows the components of the active set that are most likely to achieve the best downlink quality to be controlled and transmitted at the appropriate power level. Transmission is usually done at lower power levels by controlling the remaining downlink. In this way, transmission at a certain level that can minimize the amount of interference is performed by the downlink of the active set while maintaining the robust communication by macrodiversity communication as it is. In particular, the system according to the exemplary embodiment of the present invention provides a method for controlling transmission power used in a downlink signal from a base station to a mobile station in a macrodiversity wireless system. One exemplary method includes measuring the quality of an uplink signal received at a base station and controlling the downlink transmit power level according to the quality measurement of the uplink signal. An exemplary embodiment is a dow between a base station and a mobile station of a macrodiversity radio system. It may include a device that controls the transmission power by linking. Generally, such a device includes a means for measuring the quality of an uplink signal from a mobile station received at a base station. The control means for the amount of transmit power level used to transmit the downlink signal operates based on the quality of the uplink signal measured by the measuring means. According to an exemplary embodiment, downlink transmit power control is performed according to the corresponding uplink path gain and / or the corresponding uplink carrier-to-interference ratio.

Brief Description of Drawings The object and advantages of the present invention will be understood by reading the following detailed description in conjunction with the reference drawings. FIG. 1 depicts a conventional cellular communication system in which the present invention can be utilized. Figure 2 depicts a macrodiversity scenario in which two individual base stations communicate with a mobile station. Figure 3 depicts a macrodiversity scenario in which individual base stations communicate with mobile stations using two downlink antennas with polar offsets from each other. Figure 4 depicts a macrodiversity scenario in an indoor RF communication system, where one or more of the individual antennas communicate with the mobile station. Figure 5 depicts a macrodiversity scenario in which individual base stations communicate with mobile stations using array antennas that propagate through individual lobes. Different coverage areas are treated for each of these individual lobes. Figures 6A and 6B are circuit diagrams consisting of conventional mobile station elements and base station elements. FIG. 7 is a flow chart illustrating a processing process according to an exemplary embodiment of the present invention. FIG. 8 is a graph illustrating the results of a first simulation used to show the performance of one exemplary downlink power control system according to the present invention. FIG. 9 is a graph illustrating the results of a second simulation used to show the performance of one exemplary downlink power control system according to the present invention. FIG. 10 is a map of the floor space used according to the simulation performed using the exemplary embodiment of the present invention. Detailed Description of Recommended Examples Figure 6A is a block diagram depicting the elements of one exemplary base station 600 that has macrodiversity capability and therefore can operate in accordance with the present invention. The base station 600 includes a base station controller 602 that controls the wireless transmitter / receiver 606. The communication signals that travel to and from the wireless transmitter / receiver 606 are coupled and duplicated by one or more couplers 608, respectively. The coupler 608 can be connected to an antenna array and its respective vertical and horizontal polarized antennas, respectively. Antenna arrays are individual ground It can have beam lobes 614 and 616 covering a rational area (see, eg, Figure 5). The latter antenna configuration is similar to that illustrated in FIG. The base station control device 602 communicates with the elements of the base station transmitter / receiver 606 via the traffic bus 620, the timing bus 622, and the baseband bus 624. As will be appreciated by those skilled in the art, and as briefly described in the background section of the invention above, the present invention will be made using an alternative configuration that includes one or more base stations, each with a single antenna. Compliant macrodiversity communication can be facilitated. As depicted in FIG. 6B, one exemplary mobile station 650 includes a control device 652 coupled with a radio transmitter / receiver 654. This wireless transmitter / receiver 654 is now connected to the antenna 656. It will be appreciated by those skilled in the art that by macrodiversity operation, the mobile station 650 has the ability to recombine downlink diversity signals received from one or more base stations and / or antennas. The operation of the base station according to the exemplary embodiment of the present invention will be described with reference to FIG. In this embodiment, two separate base stations 202 and 204 are used to communicate the diversity signal to the mobile station 208. However, as those skilled in the art will understand, the diversity signals described herein can be emitted from two or more antennas of the same base station. Referring to FIG. 2, one exemplary embodiment of the present invention may include a first base station 202 and a second base station 204 of these base stations using separate downlink transmission lines 210 and 212, respectively. The common information 206 is communicated to the mobile station 208 by both parties. Communication from mobile station 208 to base stations 202 and 204 includes a first uplink 214 to first base station 202 and a second uplink 216 to second base station 204. According to one exemplary aspect of the invention, the transmit power levels used for each of the first and second downlinks 210 and 212 are for the corresponding uplinks 214 and 216. It depends on the quality measurements measured by base stations 202 and 204, respectively. One exemplary process according to the invention is illustrated in FIG. This ingenious process is adaptable in the sense that it can be used to continuously adjust the downlink power level for the active set components while the active communication process is taking place. Is desirable. Correspondingly, the process begins at step 700 with the establishment of a communication link between the base station and / or antenna in the active set and the mobile station. The components of the active set monitor and measure the characteristics and quality of the uplink from the mobile station in step 702. The downlink transmit power level is calculated as a function of the quality measurement of the uplink signal by the control system, transmitter / receiver, or similar element of the base station, or the node connected to the base station (step 704). The downlink transmit power level used for the active link is then applied to control this calculated power level (step 706). In this way, in a system operating according to the present invention, an optimum amount of downlink power is applied to each of the active components supplied to the mobile station without intruding an unnecessary amount of RF interference into the system. The downlink transmit power level used depending on the associated uplink quality can be calculated in various ways to control the downlink power. As will be appreciated by those skilled in the art, uplink quality can be measured by any variety of signal characteristics. One exemplary property that can be used according to one exemplary embodiment of the invention is path gain g. And / or processing begins at step 700 with the establishment of a communication link between the antenna and the mobile station. The components of the active set monitor and measure the characteristics and quality of the uplink from the mobile station in step 702. The downlink transmit power level is calculated as a function of the quality measurement of the uplink signal by the control system, transmitter / receiver, or similar element of the base station, or the node connected to the base station (step 704). The downlink transmit power level used for the active link is then applied to control this calculated power level (step 706). In this way, in a system operating according to the present invention, an optimum amount of downlink power is applied to each of the active components supplied to the mobile station without intruding an unnecessary amount of RF interference into the system. The downlink transmit power level used depending on the associated uplink quality can be calculated in various ways to control the downlink power. As will be appreciated by those skilled in the art, uplink quality can be measured by any variety of signal characteristics. One exemplary property that can be used according to one exemplary embodiment of the invention is path gain g. And / or processing begins at step 700 with the establishment of a communication link between the antenna and the mobile station. The components of the active set monitor and measure the characteristics and quality of the uplink from the mobile station in step 702. The downlink transmit power level is calculated as a function of the quality measurement of the uplink signal by the control system, transmitter / receiver, or similar element of the base station, or the node connected to the base station (step 704). The downlink transmit power level used for the active link is then applied to control this calculated power level (step 706). In this way, in a system operating according to the present invention, an optimum amount of downlink power is applied to each of the active components supplied to the mobile station without intruding an unnecessary amount of RF interference into the system. The downlink transmit power level used depending on the associated uplink quality can be calculated in various ways to control the downlink power. As will be appreciated by those skilled in the art, uplink quality can be measured by any variety of signal characteristics. One exemplary property that can be used according to one exemplary embodiment of the invention is path gain g. Force is applied. The downlink transmit power level used depending on the associated uplink quality can be calculated in various ways to control the downlink power. As will be appreciated by those skilled in the art, uplink quality can be measured by any variety of signal characteristics. One exemplary property that can be used according to one exemplary embodiment of the invention is path gain g. Force is applied. The downlink transmit power level used depending on the associated uplink quality can be calculated in various ways to control the downlink power. As will be appreciated by those skilled in the art, uplink quality can be measured by any variety of signal characteristics. One exemplary property that can be used according to one exemplary embodiment of the invention is path gain g._iAnd this gain is a measurement for a particular link i. Path gain (also called negative path loss) is generally associated with signal attenuation, such as that associated with an increase in distance from the transmitter from which the signal was emitted. Assuming that the total amount of transmit power P is available for the active set of downlink antennas, the downlink transmit power P used for link i_iThe level of can be determined by the following equation 1.<img file="JP4138028B2_D0001.tif" />Where P is the total power available. g_iIs the path gain measured for the uplink i. n is the number of antennas / base stations in the active set. An alternative uplink quality measure factor can be used to calculate the appropriate downlink power. For example, the downlink power level can be calculated using the carrier-to-interference (C / I) ratio in a manner similar to that described above for Equation 1. In particular, the level of downlink transmit power used for link i can be determined by Equation 2.<img file="JP4138028B2_D0002.tif" />Where P is the total power available. C_i/ I_iIs the carrier-to-interference ratio measured for the uplink i. n is the number of base stations (or antennas) in the active set. For example, in situations where other active mobile units are more likely to be in the vicinity, it may be preferable to use the C / I ratio to determine the downlink power allocation. In such situations, it is important to avoid interfering surrounding communications by introducing more interference than is necessary to achieve the desired level of communication quality that one desires. By using the uplink C / I ratio, it is possible to evaluate the degree of interference in the surroundings that currently exists. The downlink transmission power level can then be adjusted as appropriate using this ratio to avoid unnecessarily increasing interference while maintaining the desired level of communication quality. Several advantages are achieved by using the uplink characteristics that determine the appropriate power level for the corresponding downlink according to the present invention. Measuring downlink characteristics and reporting the results on a mobile station, for example in a DS-CDMA system, would result in a direct measurement of downlink quality. However, as mentioned in the background section of the invention above, the overheads and resources wasted by such systems are considerable. In contrast, the use of uplink quality measurements and the resulting measurements provides an effective means for assessing downlink characteristics. According to an exemplary embodiment of the invention, these uplink characteristics are measured in an active set base station. Therefore, there is no requirement for a dedicated frame capacity for performing measurement reports on frames transmitted on the uplink. Furthermore, base stations do not have the same processing and power restrictions as mobile stations, and the processing resources required to evaluate uplink measurements can be more easily allocated as dedicated resources. The additional power consumption for uplink data processing and dedicated to downlink power level control using the result is given the power resources available throughout the base station. It is a small amount. As a further problem, many of the uplink quality factors are readily available at the base station as they can be collected according to the operating standard requirements in which the system is operating. For example, GSM and D-AMPS systems measure uplink signal strength, path gain and C / I ratio. Therefore, even though such coefficients still seem to be useless when determining the corresponding downlink power level using the information above, these coefficients are already available to the system and the book It can be used according to an exemplary embodiment of the invention. The processing of uplink quality information in a base station can be performed in a variety of ways that will be well understood by those skilled in the art. As mentioned above, downlink power control calculations can be performed using uplink quality system variables maintained under existing standards. Returning to reference FIG. 6A, the base station controller 602 can operate according to an amplifier (not shown). The amplifier is used to drive the antenna array and / or control the level of power applied for downlink transmission. Alternatively, the components of the wireless transmitter / receiver 606 can be used to measure the uplink quality, and then such measurements can be applied to the amplifier to adjust the downlink transmit power level as appropriate. Needless to say, transmit power control and uplink measurements can be performed at one or more nodes to which the base station 600 is connected. Since the control of the amplifier and the measurement of the uplink signal can be easily performed according to the present invention, further description will be omitted. Simulations (power allocation according to the invention between active set antennas) using an indoor RF radio system similar to that depicted in Figure 4 show a very clear improvement in communication performance. It was seen. This simulation included some considerations as a model. For example, the perceived power C for a given link i was modeled by the following equation. Many of the link quality factors can be collected according to the operating standard requirements in which the system is operating and are readily available at the base station. For example, GSM and D-AMPS systems measure uplink signal strength, path gain and C / I ratio. Therefore, even though such coefficients still seem to be useless when determining the corresponding downlink power level using the information above, these coefficients are already available to the system and the book It can be used according to an exemplary embodiment of the invention. The processing of uplink quality information in a base station can be performed in a variety of ways that will be well understood by those skilled in the art. As mentioned above, downlink power control calculations can be performed using uplink quality system variables maintained under existing standards. Returning to reference FIG. 6A, the base station controller 602 can operate according to an amplifier (not shown). The amplifier is used to drive the antenna array and / or control the level of power applied for downlink transmission. Alternatively, the components of the wireless transmitter / receiver 606 can be used to measure the uplink quality, and then such measurements can be applied to the amplifier to adjust the downlink transmit power level as appropriate. Needless to say, transmit power control and uplink measurements can be performed at one or more nodes to which the base station 600 is connected. Since the control of the amplifier and the measurement of the uplink signal can be easily performed according to the present invention, further description will be omitted. Simulations (power allocation according to the invention between active set antennas) using an indoor RF radio system similar to that depicted in Figure 4 have resulted in very obvious improvements in communication performance. It was seen. This simulation included some considerations as a model. For example, the perceived power C for a given link i was modeled by the following equation. Many of the link quality factors can be collected according to the operating standard requirements in which the system is operating and are readily available at the base station. For example, GSM and D-AMPS systems measure uplink signal strength, path gain and C / I ratio. Therefore, even though such coefficients still seem to be useless when determining the corresponding downlink power level using the information above, these coefficients are already available to the system and the book It can be used according to an exemplary embodiment of the invention. The processing of uplink quality information in a base station can be performed in a variety of ways that will be well understood by those skilled in the art. As mentioned above, downlink power control calculations can be performed using uplink quality system variables maintained under existing standards. Returning to reference FIG. 6A, the base station controller 602 can operate according to an amplifier (not shown). The amplifier is used to drive the antenna array and / or control the level of power applied for downlink transmission. Alternatively, the components of the wireless transmitter / receiver 606 can be used to measure the uplink quality, and then such measurements can be applied to the amplifier to adjust the downlink transmit power level as appropriate. Needless to say, transmit power control and uplink measurements can be performed at one or more nodes to which the base station 600 is connected. Since the control of the amplifier and the measurement of the uplink signal can be easily performed according to the present invention, further description will be omitted. Simulations (power allocation according to the invention between active set antennas) using an indoor RF radio system similar to that depicted in Figure 4 have resulted in very obvious improvements in communication performance. It was seen. This simulation included some considerations as a model. For example, the perceived power C for a given link i was modeled by the following equation. It is readily available at the station. For example, GSM and D-AMPS systems measure uplink signal strength, path gain and C / I ratio. Therefore, even though such coefficients still seem to be useless when determining the corresponding downlink power level using the information above, these coefficients are already available to the system and the book It can be used according to an exemplary embodiment of the invention. The processing of uplink quality information in a base station can be performed in a variety of ways that will be well understood by those skilled in the art. As mentioned above, downlink power control calculations can be performed using uplink quality system variables maintained under existing standards. Returning to reference FIG. 6A, the base station controller 602 can operate according to an amplifier (not shown). The amplifier is used to drive the antenna array and / or control the level of power applied for downlink transmission. Alternatively, the components of the wireless transmitter / receiver 606 can be used to measure the uplink quality, and then such measurements can be applied to the amplifier to adjust the downlink transmit power level as appropriate. Needless to say, transmit power control and uplink measurements can be performed at one or more nodes to which the base station 600 is connected. Since the control of the amplifier and the measurement of the uplink signal can be easily performed according to the present invention, further description will be omitted. Simulations (power allocation according to the invention between active set antennas) using an indoor RF radio system similar to that depicted in Figure 4 have resulted in very obvious improvements in communication performance. It was seen. This simulation included some considerations as a model. For example, the perceived power C for a given link i was modeled by the following equation. It is readily available at the station. For example, GSM and D-AMPS systems measure uplink signal strength, path gain and C / I ratio. Therefore, even though such coefficients still seem to be useless when determining the corresponding downlink power level using the information above, these coefficients are already available to the system and the book It can be used according to an exemplary embodiment of the invention. The processing of uplink quality information in a base station can be performed in a variety of ways that will be well understood by those skilled in the art. As mentioned above, downlink power control calculations can be performed using uplink quality system variables maintained under existing standards. Returning to reference FIG. 6A, the base station controller 602 can operate according to an amplifier (not shown). The amplifier is used to drive the antenna array and / or control the level of power applied for downlink transmission. Alternatively, the components of the wireless transmitter / receiver 606 can be used to measure the uplink quality, and then such measurements can be applied to the amplifier to adjust the downlink transmit power level as appropriate. Needless to say, transmit power control and uplink measurements can be performed at one or more nodes to which the base station 600 is connected. Since the control of the amplifier and the measurement of the uplink signal can be easily performed according to the present invention, further description will be omitted. Simulations (power allocation according to the invention between active set antennas) using an indoor RF radio system similar to that depicted in Figure 4 show a very clear improvement in communication performance. It was seen. This simulation included some considerations as a model. For example, the perceived power C for a given link i was modeled by the following equation. Although such coefficients still appear to be useless in determining the link power level, these coefficients are already available to the system and can be used according to the exemplary embodiments of the invention. The processing of uplink quality information in a base station can be performed in a variety of ways that will be well understood by those skilled in the art. As mentioned above, downlink power control calculations can be performed using uplink quality system variables maintained under existing standards. Returning to reference FIG. 6A, the base station controller 602 can operate according to an amplifier (not shown). The amplifier is used to drive the antenna array and / or control the level of power applied for downlink transmission. Alternatively, the components of the wireless transmitter / receiver 606 can be used to measure the uplink quality, and then such measurements can be applied to the amplifier to adjust the downlink transmit power level as appropriate. Needless to say, transmit power control and uplink measurements can be performed at one or more nodes to which the base station 600 is connected. Since the control of the amplifier and the measurement of the uplink signal can be easily performed according to the present invention, further description will be omitted. Simulations (power allocation according to the invention between active set antennas) using an indoor RF radio system similar to that depicted in Figure 4 show a very clear improvement in communication performance. It was seen. This simulation included some considerations as a model. For example, the perceived power C for a given link i was modeled by the following equation. Although such coefficients still appear to be useless in determining the link power level, these coefficients are already available to the system and can be used according to the exemplary embodiments of the invention. The processing of uplink quality information in a base station can be performed in a variety of ways that will be well understood by those skilled in the art. As mentioned above, downlink power control calculations can be performed using uplink quality system variables maintained under existing standards. Returning to reference FIG. 6A, the base station controller 602 can operate according to an amplifier (not shown). The amplifier is used to drive the antenna array and / or control the level of power applied for downlink transmission. Alternatively, the components of the wireless transmitter / receiver 606 can be used to measure the uplink quality, and then such measurements can be applied to the amplifier to adjust the downlink transmit power level as appropriate. Needless to say, transmit power control and uplink measurements can be performed at one or more nodes to which the base station 600 is connected. Since the control of the amplifier and the measurement of the uplink signal can be easily performed according to the present invention, further description will be omitted. Simulations (power allocation according to the invention between active set antennas) using an indoor RF radio system similar to that depicted in Figure 4 show a very clear improvement in communication performance. It was seen. This simulation included some considerations as a model. For example, the perceived power C for a given link i was modeled by the following equation. Downlink power control calculations can be performed using quality system variables. Returning to reference FIG. 6A, the base station controller 602 can operate according to an amplifier (not shown). The amplifier is used to drive the antenna array and / or control the level of power applied for downlink transmission. Alternatively, the components of the wireless transmitter / receiver 606 can be used to measure the uplink quality, and then such measurements can be applied to the amplifier to adjust the downlink transmit power level as appropriate. Needless to say, transmit power control and uplink measurements can be performed at one or more nodes to which the base station 600 is connected. Since the control of the amplifier and the measurement of the uplink signal can be easily performed according to the present invention, further description will be omitted. Simulations (power allocation according to the invention between active set antennas) using an indoor RF radio system similar to that depicted in Figure 4 have resulted in very obvious improvements in communication performance. It was seen. This simulation included some considerations as a model. For example, the perceived power C for a given link i was modeled by the following equation. Downlink power control calculations can be performed using quality system variables. Returning to reference FIG. 6A, the base station controller 602 can operate according to an amplifier (not shown). The amplifier is used to drive the antenna array and / or control the level of power applied for downlink transmission. Alternatively, the components of the wireless transmitter / receiver 606 can be used to measure the uplink quality, and then such measurements can be applied to the amplifier to adjust the downlink transmit power level as appropriate. Needless to say, transmit power control and uplink measurements can be performed at one or more nodes to which the base station 600 is connected. Since the control of the amplifier and the measurement of the uplink signal can be easily performed according to the present invention, further description will be omitted. Simulations (power allocation according to the invention between active set antennas) using an indoor RF radio system similar to that depicted in Figure 4 have resulted in very obvious improvements in communication performance. It was seen. This simulation included some considerations as a model. For example, the perceived power C for a given link i was modeled by the following equation. Ming is omitted. Simulations (power allocation according to the invention between active set antennas) using an indoor RF radio system similar to that depicted in Figure 4 show a very clear improvement in communication performance. It was seen. This simulation included some considerations as a model. For example, the perceived power C for a given link i was modeled by the following equation. Ming is omitted. Simulations (power allocation according to the invention between active set antennas) using an indoor RF radio system similar to that depicted in Figure 4 show a very clear improvement in communication performance. It was seen. This simulation included some considerations as a model. For example, the perceived power C for a given link i was modeled by the following equation.<img file="JP4138028B2_D0003.tif" />Here, the downlink power used for link i is P._iIndicated by. Also, the average path gain g between the mobile station and the antenna_iWas modeled according to a well-known path loss prediction method. r_iHigh-speed fading was modeled as Rayleigh fading shown by, but this fading was both time- and frequency-dependent. The received interference power 1 is modeled by the following equation as the sum of the instantaneous powers generated from n interferers.<img file="JP4138028B2_D0004.tif" />The desired signal for a macrodiversity scenario, including links 1 and 2, for example, was calculated as follows.<img file="JP4138028B2_D0005.tif" />It is assumed that an equalizer in a mobile station can decompose multiple rays and add those rays coherently, for example, using maximal ratio} combining. Transmission from one of the antennas is approximately one symbol time (one symbol) The above can be achieved by delaying by time). Alternatively, the frequency offset can be selected for one of the links. The simulation included five floors and a large number of mobile stations. These mobile stations were modeled to spawn at equal probability levels across each floor. The individual floors used in this simulation are depicted in Figure 10. Each floor was covered by seven antennas placed in the same position on each floor. Each floor of the simulation was generally treated as individual cells, and these cells were treated exclusively by seven antennas. Channel reuse was limited to one channel within each cell. Channels were randomly assigned to mobile stations on each floor. For each mobile station, the two antennas with the highest average gain were selected as the macrodiversity link. Only two of the seven antennas were allowed to be used for individual mobile stations. The total amount of power split between the two antennas is constant (ie P = p)₁+ p₂)Met. System performance was measured every 1/216 seconds according to the GSM burst interval. Co-channel interference within the building was considered, but interference from adjacent channels was ignored. Other parameters of this simulation are shown in Table 1 below.<img file="JP4138028B2_D0006.tif" />This simulation result was compared with the operation configuration using a conventional single antenna. These configurations included a single cast configuration and used the average optimal link antenna of the cell for downlink transmission to the mobile station. An ideal single cast configuration was also used for comparison purposes. In this case, the system sent information from the single strongest link (one of the seven links in a cell) from burst to burst. Due to the frequency duplex distance, high-speed fading on the uplink / downlink is performed independently, so that the ideal single cast method is generally not feasible in conventional systems. Is understood by. The comparison results of the simulation are shown in Figures 8 and 9. For example, Figure 8 shows the path gain (g)._i) And the C / I proportional downlink power allocation method are compared with the case of the conventional single cast. (g_i) And the gain of the C / I proportional downlink control method are similar from 1.0 to 1.5 dB at a probability level of 10% of the cumulative distribution function (CDF). But at lower dB levels this gain is even greater. Figure 9 shows a comparison between an ideal single cast and a macrodiversity scenario. In this case, the downlink power for link i is the uplink part of link i (ie p)._i~ g_i) Measured path gain g_iIs proportional to. Notable improvements are made in that macrodiversity operation with power allocation according to the present invention shows that performance levels comparable to those of the ideal single cast scheme can be achieved. In Figure 9, the power split between the two links is equal (p).₁= p₂) The case is also drawn. This case is a clear indication that the interference level can be unnecessarily high when at least one downlink in the downlink is transmitting at too high a power level. In contrast, the interference level is reduced when using a power splitting scheme according to the present invention. According to another aspect of the invention, the uplink quality factor can be used in assessing whether a given link should be included in or removed from the active set. Such a configuration can be a useful help in making handoff decisions. For example, a given number or quality level indicating whether base stations and / or antennas should be added or removed from the active set handling mobile stations, and taken at each base station and / or antenna near the mobile station. Uplink measurements can be compared. If a mobile station moves out of one coverage area and moves out of that area, causing the uplink quality measurements in that coverage area (as measured by its corresponding base station) to fall below a certain level. The link is dropped. On the other hand, if a mobile station enters the coverage area and the uplink measurements of the corresponding base station and / or antenna rise above the quality threshold, the base station / antenna is added to the active set and then the mobile station. Can actively communicate with. Therefore, handoff can be achieved efficiently. The present invention disclosed herein relates to a macrodiversity wireless communication system. As disclosed and described herein, exemplary aspects of the invention are described in the context of cellular telephones and indoor RF communication systems with macrodiversity capabilities. However, as will be readily appreciated by those skilled in the art, the present invention can be applied to any RF communication system that can operate with macrodiversity. Such systems include, but are not limited to, optical (eg infrared) communications and PCS systems. I. Further, a system conforming to the present invention can also be applied to conventional systems such as the power split system described in the background section of the invention. Therefore, the scope of the present invention is not intended to be limited by the exemplary embodiments described herein, but is limited to the claims and equivalents provided herein. Although the present invention has been described in detail with reference to only the recommended examples, those skilled in the art will appreciate that various modifications can be made without departing from the present invention. Accordingly, the present invention is defined by the following claims intended to include all its equivalents.