JP2004023163A - Space-division multiplex communication system, base station, mobile station, space-division multiplex method, and arrival direction estimation method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To faster and more adequately determine the combination of mobile stations capable of getting space-division multiplex. <P>SOLUTION: A beam having directivity is rotated at 360° degrees from a base station 10 so as to determine the combination of the mobile stations capable of getting the space-division multiplex. During this period, each mobile station 100 measures received power simultaneously, seeks received power data at each prescribed angle unit, and transmits the data to the base station 10. The base station 10 determines the combination of the mobile stations to get the space-division multiplex based on the received power data transferred from each mobile station. It is determined at this time that two mobile stations with an angle difference wider than a prescribed angle with regard to a received power peak having a prescribed value and higher are capable of getting the space-division multiplex. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a wireless communication system such as a cellular wireless system and a wireless LAN, and more particularly to a wireless communication system in a microcell / cellular environment.
[0002]
[Prior art]
2. Description of the Related Art In recent years, for a broadband society in which large-capacity, high-speed data communication is effectively used, broadband transmission is also required in wireless communication. There is also a need for a system capable of efficiently accommodating increasing subscribers and realizing high frequency use efficiency in order to effectively use limited frequency resources.
[0003]
In order to improve the frequency use efficiency, a microcell cellular system having a small cell radius is expected to replace the conventional macrocell cellular system. An important technology in a microcell / cellular system is an array antenna. An array antenna is a sector antenna method in which the main lobe is directed only in a desired direction and low side lobes do not radiate unnecessary radio waves in an undesired direction. There is a way to aim the null in the direction and improve SINR (Signal Interference Noise Ratio). The use of array antennas to reduce interference is expected to increase system capacity.
[0004]
As a method for increasing the capacity of the system, it is known that SDMA (Space-Division-Multiple-Access) is used for the multiple access method. This spatially multiplexes a plurality of mobile stations with respect to a base station. What is important when performing space division multiplexing as a multiple access method is a slot allocation permission that determines which subscribers should be spatially multiplexed. It can be said that how to use this slot allocation method affects the performance of capacity increase more than the interference cancellation ability of the array antenna.
[0005]
Here, a conventional slot allocation method will be briefly described.
[0006]
An adaptive array antenna is mounted only on a base station, and an omnidirectional antenna is mounted on a mobile station. As a learning method of the weight coefficient of the adaptive array antenna, an RLS (Recursive Least Square) algorithm or the like is used using MMSE (Minimum Mean Square Error) as an evaluation criterion. That is, the reference signals for learning (random patterns unique to each mobile station) from all the mobile stations to be space division multiplexed are simultaneously received by the array antenna of the base station, and the above learning is performed. A method of forming a directivity pattern of an antenna in which a main lobe is directed only to a station and null is directed to another mobile station has been performed. Here, if the mobile stations to be simultaneously space-division multiplexed are located at a short distance from each other, the directions of the two mobile stations as viewed from the base station become almost the same, and learning by the MMSE-based RLS algorithm is performed. However, it has been impossible to spatially separate the two mobile stations. Whether or not the two mobile stations can be spatially separated can be determined by looking at the SINR based on the antenna pattern acquired for each mobile station. The value of SINR for a mobile station having another mobile station nearby is low (for example, 0 dB), and the value of SINR for a mobile station having good learning without another mobile station nearby is high (for example, 0 dB). 40 dB). Therefore, it has been determined whether space division multiplexing is possible based on the SINR.
[0007]
[Problems to be solved by the invention]
However, in order to make a determination based on the SINR, as described above, learning (by RLS) of the adaptive array antenna must be performed when each mobile station is simultaneously transmitting a reference signal. Further, although this learning requires a certain amount of time, if the learning is not successful, the learning time is wasted. This poses a problem particularly when handling packet data, as described below.
[0008]
Conventional methods have been targeted at relatively long calls, such as telephone calls, lasting an average of 120 seconds. Therefore, for example, when seven calls already satisfy the criteria of space division multiplexing and are being space division multiplexed, when judging whether or not a new call can be space division multiplexed, the existing seven calls and the new one are determined. Reference signals were transmitted from two mobile stations at the same time, the signals were received by the array antenna of the base station, the array antenna was learned, and the SINR value was obtained for each mobile station. Then, if the SINR of the new mobile station satisfies the condition, space division multiplexing is permitted. Further, there is also a method of permitting space division multiplexing when the SINR of a mobile station in existing space division multiplexing is satisfied.
[0009]
As described above, when a call that is continued for a relatively long time is targeted, it is sufficient to determine that one new mobile station joins a plurality of mobile stations in space division multiplexing. However, from now on, it is required to space-division multiplex packet data as short as several microseconds.
[0010]
In the case of handling packet data, the scheme that one new mobile station wishing to join the space division multiplex exists for a plurality of existing mobile stations during the space division multiplex does not apply. That is, it is necessary to instantly know the combination of mobile stations capable of space division multiplexing for each packet, that is, for each short slot. For example, if there are 100 mobile stations in the cell range of one base station, and if the upper limit of the number of units that can be simultaneously space division multiplexed is 8, the number of combinations of space division multiplexing candidates is ₁₀₀ C ₈ It becomes a huge combination. A reference signal is transmitted from eight mobile stations for each of these combinations, received by the base station, array antenna learning is performed, the SINR of each of the eight mobile stations is calculated, and the combination of the eight mobile stations is calculated. It is impossible to determine whether or not is possible for space division multiplexing. At least, it was impossible to select the best one at a time from among these huge combinations.
[0011]
In order to solve this problem, a method has been considered in which the base station side grasps in advance all information of each mobile station, and determines a mobile station to be subjected to space division multiplexing using the information. This is a method in which angle information of each mobile station viewed from the base station is accumulated in the base station, and based on the angle information, a mobile station having an angle difference of a predetermined amount or more and capable of performing space division multiplexing properly is selected. is there. However, this method may not operate well in a multipath environment because only the angle information (direction vector) is used as a criterion. That is, there is a sufficient angular difference between the mobile station A and the mobile station B (the difference in angle as viewed from the base station), and even if it is determined that space division multiplexing can be performed, the building around the mobile station A, such as a building, is not considered. Due to the influence, a multipath route exists, and one of the multipath routes may reach the base station from the same direction as the mobile station B. In this case, since there is no angle difference between the radio wave from the mobile station A and the radio wave from the mobile station B, spatial separation cannot be performed well, and space division multiplexing may not be possible.
[0012]
Therefore, a method of determining whether space division multiplexing can be performed based only on angle information has a limit in a multipath environment. Further, there is a problem in a method of acquiring the direction (direction) of each mobile station. If, for example, 100 mobile stations belong to the cell range of one base station, the direction of arrival must be estimated in order to obtain the directions of these 100 mobile stations. I can't afford the time. In addition, when the direction of arrival estimation is performed for several vehicles at a time, it becomes difficult to correspond to the mobile station and the angle information.
[0013]
The present invention has been made in view of such a background, and an object of the present invention is to provide a space division multiplexing method and a space division multiplexing communication system capable of more quickly and appropriately determining a combination of mobile stations capable of space division multiplexing. Is to provide.
[0014]
Another object of the present invention is to provide a base station and a mobile station constituting such a space division multiplex system.
[0015]
It is still another object of the present invention to provide a method of estimating a direction of arrival in which a base station can more quickly and appropriately estimate a direction of each mobile station in a space division multiplexing system.
[0016]
[Means for Solving the Problems]
A space division multiplex communication system according to the present invention includes a base station having a transmission / reception antenna capable of adjusting directivity, a plurality of mobile stations having a non-directional transmission / reception antenna, and a space division multiplex communication system. Transmission / reception antenna, a reception circuit and a transmission circuit selectively connected to the antenna, an adaptive array antenna signal processing unit connected to the reception circuit and the transmission circuit, and control for controlling the adaptive array antenna signal processing unit Unit, the mobile station is a transmitting and receiving antenna, and a power measuring means for simultaneously measuring the received power during a period when the beam from the base station rotates 360 degrees, to obtain the received power data of a predetermined angle unit, Means for transmitting its own received power data to the base station, the control unit of the base station, from each mobile station Based on the transmission received power data, and determines the combination of the mobile station to space division multiplexing.
[0017]
When determining the combination of mobile stations capable of space division multiplexing, each mobile station receives a beam rotated 360 degrees from the base station and measures the received power. The distribution of the strength of the received power can be determined in correspondence with the angle viewed from the base station. The base station collects the received power data of each mobile station, and it is possible to estimate the direction of arrival including the multipath propagation status of each mobile station based on the collected power data. As a result, spatially multiplexable mobile station combinations can be performed more appropriately.
[0018]
A base station according to the present invention is a base station in a space division multiplex communication system, and includes a plurality of transmission / reception antennas, a reception circuit and a transmission circuit selectively connected to the antennas, and a connection to the reception circuit and the transmission circuit. An adaptive array antenna signal processing unit, and a control unit for controlling the adaptive array antenna signal processing unit. The control unit performs space division multiplexing based on received power data transferred from each mobile station. Is determined.
[0019]
In this case, the base station can determine that the mobile stations whose received power peak angle difference equal to or larger than the predetermined value is equal to or larger than the predetermined angle can be space division multiplexed.
[0020]
As one aspect, the adaptive array antenna signal processing unit includes a plurality of weight processing units that add signals weighted to reception signals of the plurality of transmission / reception antennas, and a combination of mobile stations that performs space division multiplexing by the control unit. Is determined, a unique reference signal is generated for the mobile station at the same time, and at this time, one weight processing unit is configured to receive only a specific mobile station among the received signals from the plurality of mobile stations to be space-division multiplexed. Weighting processing is performed to increase the received signal strength.
[0021]
A mobile station according to the present invention is a mobile station that transmits and receives data to and from a base station in a space division multiplex communication system, and includes a transmitting and receiving antenna and a receiving power measurement during a period in which a beam from the base station rotates 360 degrees. Performing power measurement means for obtaining received power data in a predetermined angle unit, means for transmitting own received power data to the base station, and when permitted by the base station, data within a given period. And means for transmitting and receiving data.
[0022]
A space division multiplex communication method according to the present invention is a space division multiplex communication method in a communication system including a base station having a transmission / reception antenna capable of adjusting directivity and a plurality of mobile stations having a non-directional transmission / reception antenna. A step of rotating a beam having directivity by 360 degrees from a base station, and each mobile station simultaneously performs a reception power measurement during a period in which the beam from the base station rotates by 360 degrees, and a predetermined angle unit Determining the received power data of each mobile station; transmitting the own received power data from each mobile station to the base station; and performing space division multiplexing on the base station based on the received power data transferred from each mobile station. Determining a combination of mobile stations to perform.
[0023]
The transmit / receive antenna capable of adjusting the directivity is an adaptive array antenna, and the base station requests to transmit random data unique to each mobile station for a combination of mobile stations to be space-division multiplexed. The mobile station may further include a step of transmitting its own random data according to the above, and a step of performing weight learning of the adaptive array antenna based on the random data.
[0024]
In the step of transmitting the received power data to the base station, only a predetermined mobile station may transmit. The predetermined mobile station is, for example, a mobile station that attempts to transmit or receive data, or a mobile station that has undergone a predetermined change in its own received power measurement result.
[0025]
An arrival direction estimation method according to the present invention is an arrival direction estimation method for estimating the arrival directions of signals from a plurality of mobile stations having omnidirectional transmission / reception antennas in a base station having a transmission / reception antenna capable of adjusting directivity. Rotating a beam having directivity by 360 degrees from the base station; and simultaneously performing a reception power measurement by a plurality of mobile stations during a period in which the beam from the base station rotates by 360 degrees; Determining the received power data of each mobile station, transmitting the own received power data from each mobile station to the base station, and setting each base station based on the received power data transferred from each mobile station. Estimating the direction of arrival of a signal from the.
[0026]
Each mobile station receives a beam radiated by 360 degrees from the base station and measures the received power. At each mobile station, the strength of the received power can be simultaneously adjusted according to the angle viewed from the base station. The distribution state can be obtained, and the base station can collect the received power data of each mobile station and estimate the arrival direction including the multipath propagation state of each mobile station based on the collected power data.
[0027]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0028]
FIG. 1 shows a system configuration according to the present embodiment. This system includes one base station (BS) 10 and a plurality of mobile stations (MS-A, B) 100 located in a micro cell 50 centered on the base station. Before describing the operation of this system, the configurations of the base station 10 and the mobile station 100 will be described.
[0029]
FIG. 2 shows a configuration of a base station used in the present system.
[0030]
The base station 10 includes an array antenna section in which a plurality of antennas 11a, 11b, ... 11n are arranged, switches 13a, 13b, ... 13n for switching each antenna for transmission and reception, and reception RF sections 12rxa, 12rxb connected to each switch. ,... 12rxn, and the transmission RF units 12txa, 12txb,... 12txn, the adaptive array antenna signal processing unit 14 connected to the reception RF unit and the transmission RF unit, and connected to the adaptive array antenna signal processing unit 14. , And a control unit 15 that processes transmission / reception signals and controls each unit of the system. The configuration itself of such a base station 10 is known.
[0031]
FIG. 3 shows an example of the internal configuration of the receiving system of the adaptive array antenna signal processing unit 14. In this example, the adaptive array antenna signal processing unit 14 has eight weight processing units 140-1 to 140-8 having the same configuration and operating simultaneously. These weight processing units are controlled by the control unit 15, and outputs thereof are given to the control unit 15.
[0032]
Each weight processing unit has a weight coefficient calculation and storage unit 143, a plurality of multipliers 141a to 141n that multiply the output of each reception RF unit by a weight coefficient, and an adder 142 that adds these outputs. The weighting factor calculation and storage unit 143 determines the weighting factor to be given to each multiplier based on the received signal and the reference signal 145 at the time of initialization described later, and as shown in FIG. (W1a to W1n, W2a to W2n,..., W8a to W8n) are stored as the data table 30. The reference signal is a signal unique to each mobile station, and is known data used for weight learning of the mobile station. As such known data, for example, mutually different random pattern data can be used. The eight weight processing units 140-1 to 140-8 mean that up to eight mobile stations can be handled simultaneously. The weight coefficients shown in FIG. 4 are also used in the transmission system of the adaptive array antenna signal processing unit 14 (not shown).
[0033]
FIG. 5 shows a configuration of mobile station 100 according to the present embodiment. The mobile station 100 is a mobile communication terminal. Here, a mobile phone will be described as an example. The mobile station 100 has one antenna 200 and uses the antenna for both transmission and reception. The reception RF unit 202 and the transmission RF unit 203 are connected to the antenna 200 via a switch (SW) 201, and these RF units are further connected to a digital signal processing unit DSP (Digital Signal Processor) 204 that performs modulation and demodulation. ing. The DSP 204 is connected to a speaker 205, a microphone 206, an ear receiver 207, and a control unit 208. The control unit 208 is further connected to the display unit 209, the input operation unit 211, the ROM 213, the RAM 214, and the like. The control unit 208 includes a central processing unit (CPU) and the like. The input operation unit 211 corresponds to various keys and buttons, a jog dial, and the like of the mobile terminal. The ROM 213 stores a control program for realizing the operation of the present embodiment described later. The ROM 213 may include a writable memory such as a flash ROM.
[0034]
Now, a specific operation in this embodiment in such a system configuration will be described.
[0035]
FIG. 6 shows a frame format used in the present embodiment. The frame 60 includes a frame synchronization signal area 61, a received power measurement area 62, a received power data transfer area 63, and a plurality of data communication areas 64-1 to 64-7 in order from the top. In this example, seven data communication areas 64-1 to 64-7 (seven slots) are prepared, but the present invention is not limited to this. Each data communication area 64 includes a polling area 641, a known signal area 642, an uplink data area 643, and a downlink data area 644. In this example, the length of the frame 60 is 2 ms. However, the present invention is not limited to this.
[0036]
The frame synchronization signal area 61 is an area where the base station transmits a reference signal for each mobile station to perform frame synchronization. The reception power measurement area 62 is an area in which the base station scans a beam for reception power measurement from −180 degrees to +180 degrees in this area. Since each mobile station performs frame synchronization, all mobile stations measure the received power in this same area 62, sample the transition of power on the time axis, and save the result. This measurement of the received power is performed by the digital signal processing unit 204 in the mobile station 100 shown in FIG. The reception power data transfer area 63 is an area for transmitting reception power data measured by each mobile station to the base station. The antenna directivity of the base station in this area 63 is temporarily made non-directional, and data transmission from each mobile station to the base station is performed in a time-division manner. Which mobile station performs transmission in which divided time domain can be determined in advance. Alternatively, if it is not determined in advance, a person who "loses" as "first come, first served" may retry. The area 64 includes a polling area 641, a known signal transmission area 642, an uplink data area, and a downlink data area (sub-areas). The operation in each of these sub-regions will be described later.
[0037]
Here, a specific example of the 360-degree scan of the reception power measurement beam at the base station in the reception power measurement area 62 will be described. The control unit 15 determines the weight of the adaptive array for the eight weight processing units 140-1 to 140-8 of the base station 10 shown in FIG. Beam can be formed. It is also possible to freely direct this beam in a desired direction. FIG. 7 is an example of a beam of a circular array antenna when 30 antennas are used, and corresponds to a case where the beam is directed in the 0 degree direction. At the time of transmission, almost no radio waves are emitted in directions other than 0 degrees. At the time of reception, the reception sensitivity from the direction of 0 degrees reaches a peak. As described above, this beam is scanned at a constant speed and 360 degrees using the time of the reception power measurement area 62 (FIG. 6). In the example of FIG. 1, the beam 52 is scanned counterclockwise from the illustrated direction of 0 degrees. However, the rotation direction may be clockwise. From the perspective of base station 10, mobile station A is in a 90 degree direction and mobile station B is in a 270 degree direction. Therefore, the received power data at both mobile stations A and B are as shown in the graphs of FIGS. In this graph, the horizontal axis represents the angle (corresponding to the passage of time in the received power measurement area), and the vertical axis represents the received power [dB] of the mobile station. In the graph of FIG. 8, it can be seen that there is a peak 81 of the received power at the position of 90 degrees, and in the graph of FIG. 9, there is a peak 82 of the received power at the position of 270 degrees.
[0038]
Each mobile station samples the received power data measured in the received power data measurement area at a predetermined resolution (for example, in units of 1 degree), digitizes the value, and temporarily stores the value. Further, as schematically shown in FIG. 10A, a mobile station ID, which is identification information of the mobile station, is added to this data and transmitted to the base station. Instead of this, only the characteristic angle of the power value together with the mobile station ID and the power value data may be transmitted. The example shown in FIG. 10B shows the data structure in the case of transmitting the angle (not limited to one) of the peak (maximum) of the received power and the peak value together with the mobile station ID. . If the base station knows from which mobile station data is to be received in which time division area in the reception power data transfer area 63, transmission of the mobile station ID from the mobile station is not always necessary.
[0039]
In the received power data transfer area, not all mobile stations in the cell have to transmit their own received power data. For example, when the current reception power measurement result is almost the same as the previous reception power measurement result, the mobile station may omit transmission of the current reception power measurement result. Also, transmission of measurement results can be omitted for mobile stations that do not need to transmit and receive.
[0040]
When the base station obtains the received power data from each mobile station as described above, the base station determines a combination of mobile stations capable of space division multiplexing (SDMA) in the polling area, and Then, the base station transmits polling information to perform the uplink. This polling information includes the numbers of the mobile stations of the combination to be space division multiplexed. Such a mobile station number is assigned to each mobile station by a known method. Each mobile station refers to the polling information, and if it is applicable, transmits a reference signal for learning the weight of the adaptive array antenna (random data unique to each mobile station) and uplink data. The base station receives the reference signal of each mobile station, learns the weight of the array antenna by the above-described RLS algorithm based on the MMSE standard, and receives the uplink data of each mobile station using the weight. Also, the downlink data is transmitted from the base station to each mobile station in the downlink downlink region using the same weight.
[0041]
As can be seen from the frame format shown in FIG. 7, in the present embodiment, for example, seven slots (that is, seven data communication areas 64-1 to 64-7) are prepared for this SDMA in one frame. Therefore, space-division multiplexing of different combinations can be performed seven times in one frame.
[0042]
Next, a method in which the base station determines a combination of mobile stations capable of space division multiplexing in a multipath environment will be described.
[0043]
The simplest method for determining a combination that can be space-division multiplexed is, for example, a method in which a peak value obtained from received power data is converted into an angle, and a method in which peak values are separated from each other by a predetermined angle (for example, 10 degrees) or more is a space. A criterion that division multiplexing is possible is used. Furthermore, in order to cope with a multipath environment, a condition may be added that there is an angle difference of 10 degrees or more from a peak having a power equal to or more than a certain value which is considered to be caused by the multipath. For example, in the example shown in FIG. 11A, the received power data (dashed line) of a certain mobile station has peaks 91 and 92 in two directions around 90 degrees and 270 degrees due to the influence of multipath, and the other ones have different peaks. The received power data (solid line) of the mobile station has a peak 93 near 90 degrees. In this case, the peak 93 of the solid-line mobile station is likely to be spatially split from the largest peak 92 of the dotted-line mobile station since the angle difference is more than 10 degrees, but both mobile stations are likely to be spatially divided. Both have peaks 91 and 93 near 90 degrees and no angle difference of 10 degrees or more from each other. Therefore, it is determined that both mobile stations cannot be subjected to space division multiplexing in the same slot. On the other hand, even if a plurality of peaks occur in the reception power of each mobile station in a multipath environment, if there is an isolated peak having an angle difference of 10 degrees or more, the direction is used to perform space division multiplexing. It can be performed. For example, as shown in FIG. 11B, consider a case where the graph of the mobile station indicated by the solid line has a peak 94 near 180 degrees. In this case, since the peak 94 is isolated from any of the peaks 91 and 92 of the other mobile stations (the angle difference is 10 degrees or more), the two mobile stations are spatially divided using the directions of the peaks 94 and 92. Multiplexing is possible.
[0044]
Although the preferred embodiment of the present invention has been described above, various modifications and changes are possible. For example, the specific configuration of the frame shown in FIG. 6 is merely an example for describing the present invention, and the present invention is not limited to the details. Further, the specific numerical values given for the description are merely examples.
[0045]
【The invention's effect】
According to the present invention, the mobile station side simultaneously measures the received power with respect to the beam rotated by 360 degrees from the base station, and the received power data is counted and determined by the base station side, thereby arriving in a short time. The direction can be determined. In particular, since the direction of arrival estimation including the multipath propagation state can be performed, the combination of mobile stations capable of space division multiplexing can be determined more quickly and appropriately. As a result, it is suitable for application to a communication system that handles packet data. That is, a combination of mobile stations capable of space division multiplexing can be instantaneously selected in short packet units, and as a result, it is possible to contribute to an increase in the capacity of the microcell / cellular system.
[Brief description of the drawings]
FIG. 1 is a diagram showing a system configuration according to an embodiment of the present invention.
FIG. 2 is a block diagram showing a configuration example of a base station used in the system of FIG.
FIG. 3 is a diagram illustrating an example of an internal configuration of a receiving system of an adaptive array antenna signal processing unit in the base station illustrated in FIG. 2;
4 is a diagram showing a weight coefficient data table for each mobile station held by a weight coefficient calculation and storage unit in FIG. 3;
FIG. 5 is a diagram illustrating a configuration example of a mobile station in the system of FIG. 1;
FIG. 6 is a diagram showing a frame format used in the embodiment of the present invention.
FIG. 7 is an explanatory diagram of a beam having directivity by an adaptive array of a base station according to an embodiment of the present invention.
FIG. 8 is a graph showing received power data of mobile station A in a received power measurement area according to the embodiment of the present invention.
FIG. 9 is a graph showing received power data of mobile station B in a received power measurement area according to the embodiment of the present invention.
FIG. 10 is a diagram showing a configuration example (a) and (b) of data transferred to a base station in a reception power data transfer area according to an embodiment of the present invention.
FIG. 11 is a graph for explaining a method for determining a mobile station capable of spatial multiplexing according to an embodiment of the present invention.
[Explanation of symbols]
Reference Signs List 10: base station (BS), 11a to 11n: antenna, 13a to 13n: switch, 12rxa, 12rxb,. , 15 ... Control unit, 30 ... Data table, 52 ... Beam, 100 ... Mobile station (MS)

Claims (12)

In a base station having a transmit / receive antenna capable of adjusting directivity, and a plurality of mobile stations having a non-directional transmit / receive antenna and a space division multiplex communication system,
The base station comprises:
A plurality of transmitting and receiving antennas, a receiving circuit and a transmitting circuit selectively connected to the antenna,
An adaptive array antenna signal processing unit connected to the reception circuit and the transmission circuit;
A control unit for controlling the adaptive array antenna signal processing unit,
The mobile station comprises:
Transmitting and receiving antennas,
Power measurement means for simultaneously performing reception power measurement during a period in which the beam from the base station rotates 360 degrees to obtain reception power data in a predetermined angle unit;
Means for transmitting its own received power data to the base station,
A space division multiplexing communication system, wherein the control unit of the base station determines a combination of mobile stations to be space division multiplexed based on received power data transferred from each mobile station. A base station in a space division multiplex communication system,
A plurality of transmitting and receiving antennas, a receiving circuit and a transmitting circuit selectively connected to the antenna,
An adaptive array antenna signal processing unit connected to the reception circuit and the transmission circuit;
A control unit for controlling the adaptive array antenna signal processing unit,
The base station determines a combination of mobile stations to be space-division multiplexed based on received power data transferred from each mobile station. 3. The base station according to claim 2, wherein it is determined that mobile stations having a received power peak angle difference equal to or larger than a predetermined value equal to or larger than the predetermined angle can be space-division multiplexed. The adaptive array antenna signal processing unit has a plurality of weight processing units that add a signal weighted to the reception signals of the plurality of transmission and reception antennas, after the combination of mobile stations to be space division multiplexed by the control unit is determined A unique reference signal is simultaneously generated for the mobile station, and at this time, one weight processing unit increases the received signal strength of only a specific mobile station among the received signals from a plurality of mobile stations to be space division multiplexed. 3. The base station according to claim 2, wherein a weighting process is performed. A mobile station that transmits and receives data to and from a base station in a space division multiplex communication system,
Transmitting and receiving antennas,
Power measuring means for measuring received power during a period in which the beam from the base station rotates 360 degrees and obtaining received power data in a predetermined angle unit;
Means for transmitting its own received power data to the base station,
Means for transmitting and receiving data within a given period when permitted by the base station. A space division multiplex communication method in a communication system including a base station having a transmit / receive antenna capable of adjusting directivity and a plurality of mobile stations having an omnidirectional transmit / receive antenna,
Rotating a directional beam from the base station by 360 degrees;
A step in which each mobile station performs reception power measurement simultaneously during a period in which the beam from the base station rotates 360 degrees, and obtains reception power data in a predetermined angle unit;
Transmitting own received power data from each mobile station to the base station;
Based on the received power data transferred from each mobile station, the base station determines a combination of mobile stations to perform space division multiplexing,
A space division multiplexing method comprising: 7. The space division multiplexing method according to claim 6, wherein it is determined that mobile stations having an angle difference of a received power peak equal to or larger than a predetermined value are equal to or larger than a predetermined angle can be space division multiplexed. The transmit / receive antenna capable of adjusting the directivity is an adaptive array antenna,
Requesting that the base station transmit random data unique to each mobile station for a combination of mobile stations to be space division multiplexed;
8. The space according to claim 7, further comprising: a step in which the mobile station transmits its own random data in response to the request; and a step of performing weight learning of an adaptive array antenna based on the random data. Division multiplex method. 7. The space division multiplexing method according to claim 6, wherein in the step of transmitting the received power data to the base station, only a predetermined mobile station performs transmission. 10. The space division multiplexing method according to claim 9, wherein the predetermined mobile station is a mobile station that attempts to transmit or receive data. The space division multiplexing method according to claim 9, wherein the predetermined mobile station is a mobile station having a predetermined change in the result of its own received power measurement. In a base station having a transmit / receive antenna whose directivity can be adjusted, a direction-of-arrival estimation method for estimating directions of arrival of signals from a plurality of mobile stations having a non-directional transmit / receive antenna,
Rotating a directional beam from the base station by 360 degrees;
A plurality of mobile stations simultaneously perform reception power measurement during a period in which the beam from the base station rotates 360 degrees, and obtain reception power data in a predetermined angle unit;
Transmitting own received power data from each mobile station to the base station;
The base station estimates the direction of arrival of a signal from each mobile station based on the received power data transferred from each mobile station,
An arrival direction estimating method, comprising:

Images