JP2012015682A - Radio communication system, base station device and radio communication method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radio communication system which includes a plurality of base station devices 11-13 and mobile station devices 21-23 for receiving a signal wirelessly transmitted from a base station device, and which prevents interference.SOLUTION: Each of a plurality of base station devices comprises generation means for generating a plurality of mutually orthogonal data sequences from a common data sequence, which is a transmission target, by way of STBC or DSTBC, and a plurality of antennas for forming different radio communication areas. Each of the base station devices transmits signals of data sequences generated by the generation means from the antennas wirelessly. Two adjacent base station devices are set so that each of an antenna of one base station device and an antenna of the other base station device, where those antennas have an overlapped radio communication area, transmits a signal of a mutually orthogonal different data sequence.

Description

  The present invention relates to a radio communication system, a base station apparatus, and a radio communication method, and particularly to a technique for preventing interference.

  For example, as in a train radio system, a single radio area is constructed by a plurality of base station devices using the same frequency, and signals are broadcasted by a plurality of moving radio station devices (mobile station devices). In a wireless communication system, unless the ranges where radio waves from a plurality of base station devices reach are overlapped, a position where reception is not possible at each intermediate point of each base station device is created. However, if it is arranged so that radio waves from a plurality of base station apparatuses can be received at a level satisfying each other, an area in which radio waves from the plurality of base station apparatuses interfere with each other is generated. In a place where such interference occurs, a problem that reception data cannot be reproduced accurately, that is, a problem called “same wave interference” or “beat interference” occurs.

  Furthermore, the radio waves used by such systems have been forced to transmit in a narrow frequency band in response to recent radio wave conditions, and the moving body is running at a high speed of about 160 km / h from a stationary state. For example, in a stationary state, radio waves from a plurality of base station apparatuses disappear due to cancellation due to opposite phases, and in a high-speed traveling state, high-speed fading due to Doppler shift occurs, so that the propagation path state fluctuates at a considerable speed. As described above, the system cannot be constructed by uniquely determining the reception status. Furthermore, in the case of broadcast radio in which there are a plurality of mobile bodies, each reception state varies for each mobile body, and individual measures such as changing the antenna beam are difficult.

FIG. 4 shows a configuration example of a train radio system as an example of the broadcast radio system.
The system of this example includes a central device 101, a plurality of base station devices 111 to 113 that are arranged along the track 102, and are respectively separated from each other, and a plurality of mobile station devices 121 that are trains that travel on the track 102. To 123.
Here, the central apparatus 101 is connected to each base station apparatus 111-113. Each base station apparatus 111 to 113 has two antennas ANT111-1, ANT111-2 to ANT113-1, and ANT113-2, and the line 102 is in the radio area of the plurality of base station apparatuses 111 to 113. Covers the entire area along the line. Moreover, the track | line is generally comprised from the straight line and the curve.

An example of the operation in the system of this example will be shown.
The central apparatus 101 generates a data string S to be transmitted to the mobile station apparatuses 121 to 123 and transmits the data string S to the base station apparatuses 111 to 113. Here, the data string S is, for example, data obtained by converting voice into data or data including meaningful information.
Each base station apparatus 111 to 113 converts (for example, modulates) the data string S received from the central apparatus 101 into a data string for transmission, and transmits the same data to each antenna ANT111-1, ANT111-2 to ANT113-. 1. Wireless transmission from ANT113-2.
Each of the mobile station apparatuses 121 to 123 receives a signal (radio wave) wirelessly transmitted from the base station apparatuses 111 to 113 in a broadcast manner.

Here, the mobile station apparatus 121 is present at a position where the radio wave of the base station apparatus 111 is mainly received, the mobile station apparatus 123 is present at a position where the radio wave of the base station apparatus 113 is mainly received, and the mobile station apparatus 122 is the base station. It exists in the position which receives what added the radio wave of the apparatus 111 and the radio wave of the base station apparatus 112. FIG.
In this example, each of the mobile station apparatus 121 and the mobile station apparatus 123 can receive radio waves from a single base station apparatus and reproduce data.
On the other hand, since the mobile station device 122 receives two synthesized radio waves, for example, when the intensity of each radio wave is the same and the phase shift due to the spatial delay is reversed by 180 degrees, the received signal is canceled. Occurs. Also, if the frequencies are not the same but different, the combined received signal has a periodic drop in electric field strength, which again makes it impossible to receive data.

This will be described in detail with reference to FIGS.
FIG. 5 shows an example of radio wave interference from two adjacent base station apparatuses 111 and 112.
FIGS. 6A and 6B show an example of combining two signals (radio waves).
The mobile station apparatus 132 and the mobile station apparatus 133 shown in FIG. 5 receive only radio waves from one base station apparatus, and thus no interference occurs. However, the mobile station apparatus 131 has radio waves from two base station apparatuses 111 and 112. Interference occurs, and the phenomenon shown in FIGS. 6A and 6B occurs.

As shown in FIG. 6 (a), when the frequency is different between the signal from the first base station apparatus and the signal from the second base station apparatus, the electric field strength is periodically generated in the synthesized received signal. Will occur.
As shown in FIG. 6 (b), when the frequency is the same between the signal from the first base station apparatus and the signal from the second base station apparatus, In the combined received signal, the electric field strength may drop.

  As an example of a known countermeasure against such a phenomenon, for example, in a plurality of base station apparatuses that are respectively tuned, radio wave interference can be achieved by intentionally shifting transmission timing between base station apparatuses that interfere adjacent to each other. There has been proposed a method of preventing and reproducing inter-symbol interference generated by shifting transmission timing by using an equalizer prepared on the receiving side. However, in this method, since interference is intentionally generated from the beginning, complicated processing is required on the receiving side, and there is a drawback that efficient demodulation cannot always be performed for the complexity.

IEICE TRANSACTIONS on Communications, VOL. E92-B, NO. 6. JUNE 2009

As described above, conventionally, in a broadcast type radio system such as a train radio system, further development has been required in terms of preventing interference.
The present invention has been made in view of such a conventional situation. For example, in a broadcast type radio system in which signals are transmitted from a plurality of base station apparatuses using a single frequency, interference can be prevented. It is an object of the present invention to provide a wireless communication system, a base station apparatus, and a wireless communication method.

(Configuration example of wireless communication system)
In order to achieve the above object, in the present invention, a radio communication system having a plurality of base station apparatuses and a mobile station apparatus that receives signals transmitted from the base station apparatuses by radio is configured as follows.
That is, in each of the plurality of base station apparatuses, the generation unit uses a space-time block code (STBC) or a differential space-time block code (DSTBC) to generate a plurality of data orthogonal to each other from a common data sequence to be transmitted. A sequence is generated, and a plurality of antennas forming different radio communication areas are used, and a signal of the data sequence generated by the generation unit is transmitted from the antenna by radio.
Further, in the wireless communication system, for two adjacent base station apparatuses, signals of different data strings orthogonal to each other are received from each of the antennas of one base station apparatus and the antenna of the other base station apparatus with overlapping wireless communication areas. It is set to be sent.

  Therefore, for two adjacent base station apparatuses, even in an area where the radio communication areas of the antenna of one base station apparatus and the antenna of the other base station apparatus overlap, signals of different data strings orthogonal to each other are transmitted from each antenna. Since the data is transmitted, the mobile station apparatus can receive the synthesized signal and reproduce the original data string. Thus, for example, in a broadcast radio system that transmits signals from a plurality of base station devices using a single frequency, interference can be prevented.

Here, any of STBC and DSTBC may be used in the system.
Further, for example, a data string (common data string) to be transmitted is simultaneously distributed (transmitted) from a predetermined common device (for example, a central device) to each of a plurality of base station devices.

In addition, for example, signals of the same frequency are transmitted by radio in each antenna of a plurality of base station apparatuses, but a plurality of different frequencies may be used as another configuration example.
Further, regarding the formation of different wireless communication areas by a plurality of antennas provided in one base station apparatus, for example, an arbitrary two antennas may have areas where the wireless communication areas overlap.
Moreover, as each antenna of a base station apparatus, a directional antenna can be used, for example.
For example, when one base station apparatus includes three or more antennas, the present configuration may be applied to some (two or more) antennas.

(Configuration example of base station device)
In order to achieve the above object, in the present invention, a base station apparatus that transmits signals to a mobile station apparatus by radio is configured as follows.
That is, the generation unit generates a plurality of data sequences orthogonal to each other from the data sequence to be transmitted using STBC or DSTBC, and uses a plurality of antennas forming different wireless communication areas. And it is set so that signals of different data sequences generated by the generating means may be transmitted from each of the plurality of antennas.

  Therefore, since signals of different data strings orthogonal to each other are transmitted from each of the plurality of antennas of the base station apparatus, signals from these antennas may arrive, for example, directly below the base station apparatus. Even in such a region, the receiving side can reproduce the original data string from the received signal. In this way, it is possible to prevent interference.

Here, any of STBC and DSTBC may be used.
Moreover, in each antenna of the base station apparatus, for example, signals of the same frequency are transmitted wirelessly, but as another configuration example, a plurality of different frequencies may be used.
In addition, regarding the formation of different wireless communication areas by a plurality of antennas provided in the base station apparatus, for example, an arbitrary two antennas may have areas where the wireless communication areas overlap.
Moreover, as each antenna of a base station apparatus, a directional antenna can be used, for example.
Further, for example, when the base station apparatus includes three or more antennas, this configuration may be applied to some (two or more) of the antennas.

(Configuration example of a wireless communication method corresponding to the above-described wireless communication system)
To achieve the above object, the present invention provides a radio communication method in which signals are transmitted from a plurality of base station apparatuses by radio, and a mobile station apparatus receives signals transmitted from the base station apparatus by radio as follows. Perform proper processing.
That is, each of the plurality of base station apparatuses generates a plurality of data sequences orthogonal to each other from a common data sequence to be transmitted using STBC or DSTBC, and uses the plurality of antennas that form different wireless communication areas. The data string signal generated by the generation means is transmitted by radio. In this case, for two adjacent base station apparatuses, the antenna of one base station apparatus and the antenna of the other base station apparatus with overlapping radio communication areas Are transmitted with signals of different data sequences orthogonal to each other.

  Therefore, for two adjacent base station apparatuses, even in an area where the radio communication areas of the antenna of one base station apparatus and the antenna of the other base station apparatus overlap, signals of different data strings orthogonal to each other are transmitted from each antenna. Since the data is transmitted, the mobile station apparatus can receive the synthesized signal and reproduce the original data string. Thus, for example, in a broadcast radio system that transmits signals from a plurality of base station devices using a single frequency, interference can be prevented.

  As described above, according to the present invention, it is possible to prevent interference in a broadcast radio system in which signals are transmitted from a plurality of base station apparatuses using a single frequency, for example.

It is a figure which shows the structural example of the broadcast type radio | wireless system which concerns on one Example of this invention. It is a figure which shows an example of the mode of the interference of the electromagnetic wave from two adjacent base station apparatuses. (A) is a figure which shows the structural example regarding the modulation process in a base station apparatus, (b) is a figure which shows the structural example regarding the demodulation process in a mobile station apparatus. It is a figure showing an example of composition of a broadcast type radio system. It is a figure which shows an example of the mode of the interference of the electromagnetic wave from two adjacent base station apparatuses. (A), (b) is a figure which shows the example of a synthesis | combination of two signals (radio waves).

Embodiments according to the present invention will be described with reference to the drawings.
As one of MIMO (Multi-Input Multi-Output) which is a wireless transmission method that has been attracting attention recently, a modulation signal is calculated by a base station apparatus on the transmission side, and a plurality of modulation signals orthogonal to each other from one modulation signal sequence A method has been proposed in which a sequence is generated, transmitted by separate antennas, and demodulated on the receiving side to obtain a diversity effect in time and space (for example, Alamouti space-time code (STBC : Space Time Block Code)).

Here, the above-described method has a drawback that training is not in time in an environment of fast fading (fast fading) in which propagation path parameters change every moment.
Therefore, as an application, a differential space-time block code (DSTBC: Differential STBC) that delays a transmission symbol and encodes a difference before space-time coding on the transmission side has been proposed (for example, Traohh's). Differential STBC).

In these transmission diversity systems, it is possible to generate a plurality of transmission sequences from one signal sequence, and since these are orthogonal, a data error occurs even if a plurality of transmission sequences are combined and received. It is known that the original signal sequence can be demodulated without it.
In this example, two orthogonal data sequences generated by STBC and DSTBC are used to develop from arranging and transmitting two antennas in a single base station apparatus which is a basic use example of MIMO. Each of the two antennas has directivity so that different series of transmission waves interfere in a radio wave interference region generated between adjacent base station apparatuses. As a result, for example, data that conventionally cannot be received due to a data error in the interference region can be received correctly.

FIG. 1 shows a configuration example of a train radio system as an example of a broadcast radio system according to an embodiment of the present invention.
The system of this example includes a central device 1, a plurality of base station devices 11 to 13 that are arranged along the track 2, and installed at positions separated from each other, and a plurality of mobile station devices 21 that are trains that travel on the track 2. To 23.
Here, the central apparatus 1 is connected to each base station apparatus 11-13. Each of the base station apparatuses 11 to 13 has two antennas ANT11-1, ANT11-2 to ANT13-1, and ANT13-2, and a line 2 is provided in the radio area of the plurality of base station apparatuses 11 to 13. Covers the entire area along the line. Moreover, the track | line is generally comprised from the straight line and the curve.

An example of the operation in the system of this example will be shown.
The central apparatus 1 generates a data string S to be transmitted to the mobile station apparatuses 21 to 23 and transmits the data string S to the base station apparatuses 11 to 13. Here, the data string S is, for example, data obtained by converting voice into data or data including meaningful information.
Each base station apparatus 11-13 converts (for example, modulates) the data string S received from the central apparatus 1 into a data string for transmission, and then each antenna ANT11-1, ANT11-2 to ANT13-1, ANT13- 2 is transmitted wirelessly.
Each mobile station apparatus 21-23 receives the signal (radio wave) transmitted by radio from the base station apparatuses 11-13 in a broadcast manner.

  In this example, each of the base station apparatuses 11 to 13 receives the data string S to be transmitted from the central apparatus 1, and performs data string A and orthogonal to each other from the transmission source data (data string S) by STBC conversion or DSTBC conversion. A data string B is generated. And each base station apparatus 11-13 converts one produced | generated data sequence A into a radio wave, transmits it from one antenna ANT11-1 to 13-1, and also produced | generated the other produced data sequence B by radio | wireless. It converts into a radio wave and transmits from the other antenna ANT11-2 to 13-2.

In the example of FIG. 1, the base station apparatus 11 transmits the data string A from the antenna ANT11-1, and transmits the data string B from the antenna ANT11-2. Further, the base station apparatus 12 adjacent to the base station apparatus 11 transmits the data string A in the antenna ANT12-1 that interferes with the radio wave (data string B) from the antenna ANT11-2 of the base station apparatus 11, and the antenna ANT12. -2 transmits the data string B. Similarly, the base station apparatus 13 adjacent to the base station apparatus 12 transmits the data string A through the antenna ANT13-1, and transmits the data string B through the antenna ANT13-2.
The antennas ANT11-1, 11-2 to ANT13-1, 13-2 are arranged in consideration of directivity so that transmission waves of the same data string do not overlap each other.

In this example, as each antenna ANT11-1, 11-2 to ANT13-1, 13-2 of each base station apparatus 11-13, for example, a directional antenna is used. Moreover, in each base station apparatus 11-13, the radio area of one antenna ANT11-1 to 13-1 and the radio area of the other antenna ANT11-2 to 13-2 may overlap, but are different. It is set to be an area.
Further, in this example, the frequencies of radio signals transmitted from the antennas ANT11-1, 11-2 to ANT13-1, 13-2 of the base station apparatuses 11 to 13 are the same, but other configurations As an example, a configuration in which a plurality of different frequencies are properly used may be used.

  Thus, in this example, when the radio area formed by each of the antennas ANT11-1, 11-2 to ANT13-1, 13-2 of the plurality of base station apparatuses 11 to 13 is viewed, it is caused by STBC conversion or DSTBC conversion. Two or more data series (in this example, two data strings A and B) are alternately assigned to adjacent wireless areas.

  Here, the mobile station device 21 is present at a position that mainly receives radio waves of the data string A from the base station apparatus 11, and the mobile station device 23 is located at a position that mainly receives radio waves of the data string B from the base station device 13. The mobile station device 22 exists at a position to receive the sum of the radio wave of the data string B from the base station device 11 and the radio wave of the data string A from the base station device 12.

In this example, each of the mobile station device 21 and the mobile station device 23 can receive a single radio wave from a single base station device and reproduce data. That is, when only the data string A or the data string B is received, there is no interference, so that the original transmission signal (data string S) can be demodulated.
Further, in this example, the data strings A and B to be transmitted for each antenna of each base station apparatus 11 to 13 are devised and arranged, so that an area directly below each base station apparatus 11 to 13 or an adjacent base station In the radio wave interference area with the device, the mobile station device (for example, the mobile station device 22) receives a signal in which the data string A and the data string B are combined. In this case, the mobile station apparatus (for example, mobile station apparatus 22) can demodulate the original transmission signal (data sequence S) by using the decoding of the code (STBC or DSTBC) on the transmission side.

This will be described in detail with reference to FIG.
FIG. 2 shows an example of radio wave interference from two adjacent base station apparatuses 11 and 12.
The mobile station apparatus 32 shown in FIG. 2 receives only one radio wave of the data string B from one base station apparatus 11, so no interference occurs. In the mobile station apparatus 33, one mobile station apparatus 32 receives one radio wave from one base station apparatus 12. Since only the radio wave of the data string A is received, no interference occurs. Further, since the mobile station apparatus 31 receives radio waves of different orthogonal data strings B and A from the two base station apparatuses 11 and 12, the original data string S can be demodulated.

  FIG. 3 (a) shows a configuration example regarding the modulation processing in the base station apparatus, and FIG. 3 (b) shows a configuration example regarding the demodulation processing in the mobile station apparatus. 3A and 3B show a configuration example in the case where the DSTBC is used, but STBC may be used as another configuration example.

  In the example of FIG. 3A, in the base station apparatus, the data string S to be transmitted is temporarily stored by the serial / parallel converter 41 and output to the symbol calculator 42 for each symbol. The symbol calculation unit 42 outputs the data to be output to the space-time coding (STBC) unit 44 and also outputs it to the delay unit 43. Then, the symbol calculation unit 42 calculates the difference data of the data input from the serial / parallel conversion unit 41 with the previous data based on the input from the delay unit 43, and performs space-time coding ( (STBC) unit 44 and delay unit 43. The delay unit 43 delays the data input from the symbol calculation unit 42 and outputs the delayed data to the symbol calculation unit 42. The space-time encoding (STBC) unit 44 generates two orthogonal data strings A and B by space-time encoding the difference data calculated in this way, and outputs them to the corresponding antennas. .

  As another configuration example, a selector is provided at the subsequent stage of the space-time coding (STBC) unit 44, and two orthogonal data sequences A input from the space-time coding (STBC) unit 44 by the selector. , B may be used to output to a predesignated antenna.

Here, the arrangement of the data strings A and B is converted in time sequence so that they do not cancel each other even if they are added when viewed in a moment. As a result, since the data A and B received and added by the mobile station apparatus do not cancel each other, even if radio wave interference occurs, the data is decoded from the difference from the data received immediately before by differential decoding. The desired data string S can be reproduced by the code determination.
In the example of FIG. 3B, the mobile station apparatus decodes the received data string A or data string B or their combined data by the differential decoding unit 51 and determines the code by the code determination unit 52. A desired data string S is obtained.

For this reason, in FIG. 1, the mobile station apparatus 21 that receives only the data string A can sufficiently obtain the ratio (D / U) of the desired wave and the undesired wave. Similarly, the mobile station device 23 that receives only the data string B can also expect the line quality of a single wave of the data string B.
Further, in the mobile station device 22 (for example, as shown in FIG. 4, a mobile station device that has been in a radio interference area and has deteriorated line quality as shown in FIG. 4) in which the data sequence A and the data sequence B are combined, Due to the diversity effect caused by the above, an effect more than the conventional one can be expected.

Here, such a thing has an advantage that, for example, the receiving side is possible with a single antenna arrangement (for example, a minimum antenna arrangement), and there is no need to perform complicated processing by an equalizer or the like. ing.
Furthermore, in the system in which the line design that minimizes the radio wave interference area is performed in the past, in this example, the radio wave interference rather improves the reception efficiency, so that the line design is facilitated. .

As described above, in this example, the central device 1, the plurality of base station devices 11 to 13, and the mobile station devices 21 to 23 that perform radio communication with the base station devices 11 to 13 while moving are provided. 1 broadcast type radio system in which a plurality of base station apparatuses 11 to 13 simultaneously transmit voice and data transmitted from 1 at the same frequency and receive the signals by a plurality of mobile station apparatuses 21 to 23 that move at different positions. The following configuration was adopted.
That is, the base station apparatuses 11 to 13 encode the original bit string (in this example, the data string S) with a space-time block code (STBC) or a differential space-time block code (DSTBC), and generate a plurality of encodings. Bit strings (in this example, data strings A and B) are transmitted from a plurality of antennas, respectively, and arranged so that different encoded bit strings interfere with each other in adjacent base station apparatuses.

  Further, in the broadcast type wireless system of this example, the reception side (in this example, the mobile station devices 21 to 23) decodes the signals that are space-time block coded, thereby receiving signals received from a plurality of antennas. The original transmission bit string (in this example, data string S) is reproduced from the synthesized wave.

  Thus, in this example, each base station apparatus 11-13 encodes a transmission signal with STBC or DSTBC, and assigns a plurality of generated encoded sequences (data series) to a plurality of antennas, respectively. By selecting the directivity of the antenna so that different encoded sequences are transmitted in adjacent base station devices, transmission waves of different encoded sequences interfere in an interference region between adjacent base station devices. On the receiving side, for example, the space-time block code can be decoded from the synthesized signal, and the original transmission data sequence can be reproduced.

  Therefore, in this example, for example, in a broadcast radio system in which a single frequency signal is transmitted from a plurality of base station apparatuses 11 to 13, received data can be reproduced even in an interference area between the base station apparatuses. it can. As a result, even in a radio wave interference area that occurs when radio waves are broadcast from a plurality of base station apparatuses 11 to 13 using a single frequency, the influence of the radio wave interference is removed and the reliability is improved. Can provide a high line.

  In the broadcast type radio system (an example of a radio communication system) of this example, the processing units 41 to 44 (when using DSTBC) as shown in FIG. Thus, the generating means is configured by the function of generating a plurality of data sequences A and B orthogonal to each other from the data sequence S to be transmitted, and a plurality of antennas ANT11-1 and 11 that form different wireless communication areas. -2 to ANT13-1, 13-2.

  Here, in this example, the configuration example in which each base station apparatus wirelessly transmits signals of different data sequences orthogonal to each other from two antennas is shown. However, as another configuration example, each base station apparatus has one data In a system that wirelessly transmits a sequence of signals, two adjacent base station apparatuses use different orthogonal data sequences (for example, data sequences A and B) generated by STBC or DSTBC from the data sequence S from the central device. It is also possible to implement a configuration in which one signal is transmitted from one base station apparatus and the other signal is transmitted from the other base station apparatus. In this case, for example, conventionally, when a system is operated with a plurality of base station apparatuses using the same frequency, radio wave interference has occurred in the overlapping areas in the communication areas of adjacent base station apparatuses. On the other hand, in this configuration example, each base station apparatus encodes a transmission signal by STBC or DSTBC, and selects a transmission data sequence for each base station apparatus so that a different encoded sequence is transmitted by the adjacent base station apparatus. By doing so, interference with the same wave can be prevented.

Here, the configuration of the system and apparatus according to the present invention is not necessarily limited to the configuration described above, and various configurations may be used. The present invention can also be provided as, for example, a method or method for executing the processing according to the present invention, a program for realizing such a method or method, or a recording medium for recording the program. It is also possible to provide various systems and devices.
The application field of the present invention is not necessarily limited to the above-described fields, and the present invention can be applied to various fields.
In addition, as various processes performed in the system and apparatus according to the present invention, for example, the processor executes a control program stored in a ROM (Read Only Memory) in hardware resources including a processor and a memory. A controlled configuration may be used, and for example, each functional unit for executing the processing may be configured as an independent hardware circuit.
The present invention can also be understood as a computer-readable recording medium such as a floppy (registered trademark) disk or a CD (Compact Disc) -ROM storing the control program, and the program (itself). The processing according to the present invention can be performed by inputting the program from the recording medium to the computer and causing the processor to execute the program.

  1, 101 ··· Central device, 2, 102 ·· Line, 11 to 13, 31 to 33, 111 to 113 ·· Base station device, 21 to 23, 121 to 123, 131 to 133 ·· Mobile station device, ANT11 -1 to ANT13-1, ANT11-2 to ANT13-2, ANT1111-1 to ANT113-1, ANT111-2 to ANT113-2, antenna 41, serial / parallel conversion unit 42, symbol calculation unit, 43 ... Delay unit 44 ... Space-time coding (STBC) unit 51 ... Differential decoding unit 52 ... Code determination unit

Claims (3)

In a radio communication system having a plurality of base station apparatuses and a mobile station apparatus that receives signals transmitted from the base station apparatus by radio,
Each of the plurality of base station apparatuses includes a generation unit that generates a plurality of data sequences orthogonal to each other from a common data sequence to be transmitted using STBC or DSTBC, and a plurality of antennas that form different wireless communication areas. And wirelessly transmitting a signal of the data string generated by the generating means from the antenna,
In the radio communication system, signals of different data strings orthogonal to each other are transmitted from two antennas of one base station apparatus and the antennas of the other base station apparatus, which have overlapping radio communication areas, for two adjacent base station apparatuses. Set to
A wireless communication system. In a base station device that wirelessly transmits a signal to a mobile station device,
A generating unit that generates a plurality of data sequences orthogonal to each other from a data sequence to be transmitted using STBC or DSTBC, and a plurality of antennas that form different wireless communication areas,
Each of the plurality of antennas is set to transmit signals of different data sequences orthogonal to each other generated by the generation unit,
A base station apparatus. In a wireless communication method in which signals are transmitted from a plurality of base station devices by radio, and a mobile station device receives signals transmitted from the base station devices by radio,
Each of the plurality of base station apparatuses generates a plurality of data sequences orthogonal to each other from a common data sequence to be transmitted using STBC or DSTBC, and generates the generation means from a plurality of antennas forming different radio communication areas Wirelessly transmit the data string signal generated by
In this case, for two adjacent base station apparatuses, signals of different data sequences orthogonal to each other are transmitted from each of the antennas of one base station apparatus and the antennas of the other base station apparatus with overlapping wireless communication areas.
A wireless communication method.

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