JP2000068959A - Radio transmission device and radio communication equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simultaneously transmit data to a plurality of terminals with one slot and to improve transmission efficiency by hierarchizing data and hierarchy-multiplexing/transmitting data through the use of a hierarchy modulation system when data is transmitted to a plurality of radio terminals from the radio base station by a TDMA system. SOLUTION: Whenever a radio transmission/reception part 12 receives a signal from a radio terminal, a reception level measurement part 13 measures a signal level and stores it in a terminal information storage part 16 with transmission source terminal information taken in a demodulation circuit 17. On the other hand, transmission data to the radio terminal is once accumulated in a transmission buffer 18 and a buffer control part 19 decides the hierarchizing of output data based on terminal information of the terminal information storage part 16. Transmission data is sent from the transmission buffer 18 to a hierarchy modulation circuit 15. Resistance against noise is improved by allocating data to the hierarchy of the signal of high quality in order from the smallest reception level. Hierarchy is modulated and the radio transmission/reception part 12 transmits data as a transmission frequency. Thus, transmission success probability is improved and transmission efficiency is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for wireless communication between one wireless base station and a plurality of terminals. The present invention is a technique developed for a wireless LAN (Local Area Network) used at a short distance such as in one room or in one building, but can be widely used in other areas. The present invention relates to multiplex modulation for simultaneously modulating information of a plurality of lines destined for a plurality of terminals on one carrier wave, and more particularly to a technique of providing a grade (layer) of communication quality to a plurality of multiplex-modulated lines. Modulation with different qualities according to the importance of information is expressed in the field of image processing technology as "hierarchical modulation". In this specification, the communication quality of a plurality of lines is graded (hierarchy). And performing multiplex modulation on one carrier is referred to as “hierarchical modulation”.

[0002]

2. Description of the Related Art Conventionally, a wireless LAN has been used as one of systems for performing communication between a plurality of wireless terminals and one wireless base station.
There is. In this wireless LAN system, a plurality of wireless terminals share a certain communication line allocated for communication with one wireless base station to perform communication.
The communication line is divided by frequency and time, and the divided communication line is allocated to communication with one wireless terminal to perform communication. At this time, the method of dividing the frequency is called frequency multiplex access (FDMA), and the method of dividing time is called time multiplex access (TDMA).

In the above system, in order to improve the efficiency of use of communication lines, communication lines divided by frequency or time are not fixedly allocated to each wireless terminal, but data to be transmitted is generated. To assign a communication line to each destination wireless terminal each time it is performed (called a reservation method)
There is. This allows one wireless base station to efficiently communicate with more wireless terminals using a limited band.

FIG. 8 shows an example of a transmission frame for transmitting data between a wireless base station and each wireless terminal when the TDMA method is used and the above-described reservation method is used.
The reserved slot is used for reserving a communication line used by the wireless terminal for the wireless base station or for notifying the wireless terminal of the communication line used for the wireless terminal. The permission slot is used by the wireless base station to allow the wireless terminal to transmit. The data slot is used for transmitting data. The confirmation slot is used for confirming whether data transmission to the wireless base station and the wireless terminal has been correctly performed.
The reservation, permission, data, and confirmation slots are further divided into a plurality of minislots as shown in a data minislot in FIG. 8 for temporal multiplexing.

[0005] When transmitting a data packet from a wireless base station to a wireless terminal, the wireless base station broadcasts a wireless terminal as a destination using a reserved slot prior to data transmission. Thereafter, the wireless base station sequentially transmits data packets addressed to each wireless terminal using the data minislot divided by time. Then, the wireless terminal that has been notified of the data transmission earlier receives the data packet transmitted from the wireless base station in the notified data mini-slot, and if this is correctly received, the wireless terminal transmits the confirmation signal to the data slot that has received the confirmation signal. Send in the corresponding confirmation mini-slot.

[0006]

In recent years, with the spread of computers and the increase in multimedia communication, wireless LAN
In a wireless packet communication system represented by a system, an increase in the number of wireless terminals capable of communicating with one wireless base station, an improvement in transmission efficiency, and an increase in transmission capacity are desired.

As described above, in the TDMA system,
Since the communication line divided by time is shared and used by a plurality of terminals, as can be seen from the configuration of the transmission frame in FIG.
At most one data packet can be transmitted in one slot, and it cannot be simultaneously transmitted to a plurality of wireless terminals in one slot. For this reason, when the number of wireless terminals communicating with one wireless base station increases, the number of data packets waiting to be transmitted to the wireless base station increases, resulting in a decrease in transmission quality such as an increase in transmission delay. In addition, the transmission efficiency may be reduced due to packet collision or the like. Further, there arises a problem that the capacity of a buffer for storing data packets to be transmitted in the wireless base station must be increased.

[0008] The present invention has been made in such a background, and a TD is transmitted from one radio base station to a plurality of radio terminals.
An object of the present invention is to provide a wireless transmission device and a wireless communication device that enable simultaneous transmission of data to a plurality of wireless terminals when transmitting data in the MA system. An object of the present invention is to provide a wireless transmission device and a wireless communication device capable of improving transmission efficiency and increasing transmission capacity. An object of the present invention is to provide a wireless transmission device and a wireless communication device that can increase the transmission success probability of transmission data. An object of the present invention is to provide a wireless transmission device and a wireless communication device that can improve signal transmission quality. An object of the present invention is to provide a wireless transmission device and a wireless communication device that can reduce the capacity of a transmission buffer of a wireless base station that stores data to be transmitted. An object of the present invention is to provide a wireless transmission device and a wireless communication device capable of increasing the number of wireless terminals capable of communicating with one wireless base station.

[0009]

SUMMARY OF THE INVENTION The present invention uses a hierarchical modulation scheme to transmit data addressed to a plurality of wireless terminals from a wireless base station using different modulation symbols. Hierarchical multiplexing with signals of different qualities and transmission are performed by assigning layers to bits. Thereby, the wireless base station can simultaneously transmit to a plurality of wireless terminals in one slot. Further, the wireless base station, when layering data addressed to a plurality of wireless terminals, based on the reception level of a signal transmitted last from a wireless terminal that has been measured in advance, to a wireless terminal having a small reception level. , And the data is sequentially allocated to a higher-quality signal hierarchy and transmitted.

Generally, a radio terminal having a low received signal level is located at a point far from the radio base station, and a radio terminal having a large reception signal level is located at a point near the radio base station. Data for a wireless terminal having a low reception level and generally located far from the wireless base station is allocated to a high-quality signal and transmitted with high resistance to noise. Even if the transmission path is somewhat poor, the transmission success probability can be increased.

In addition, data to a radio terminal having a high reception level and generally located near a radio base station has a relatively low quality because the transmission path between the radio terminal and the radio base station is relatively good. , The transmission success probability does not decrease.

As a result, the transmission success probability of the data transmitted from the radio base station is improved, and not only the capacity of the buffer of the radio base station for storing the data to be transmitted can be reduced, but also the data transmission delay can be reduced, and Transmission efficiency can be improved.

In the case where each wireless terminal has the required communication quality, the transmission quality is assigned in the order of the required quality, so that the transmission success probability of the data is improved. Not only can the buffer capacity of the wireless base station storing the waiting data be reduced, but also the data transmission delay can be reduced and the transmission efficiency can be improved.

That is, a first aspect of the present invention is a radio transmitting apparatus, which comprises a modulating means for simultaneously multiplex modulating information of N lines on which individual communication information for a plurality of N destination terminals is transmitted to one carrier. Wireless transmission device provided.

Here, a characteristic of the present invention is that a plurality of types of lines having different communication qualities are set in the modulating means, and a means for allocating a line to each destination terminal according to the required communication quality is provided. Including.

The required communication quality is set in accordance with the distance between the destination terminal and the own radio transmitting apparatus. At this time, means for detecting a signal level received from the destination terminal, and means for detecting Means for estimating the distance in accordance with the received signal level obtained.

That is, for a destination terminal that is far from the own radio transmitting apparatus, it is expected that the received signal level at the destination terminal will decrease and the C / N (carrier-to-noise ratio) will decrease. Allocating a line with good communication quality is necessary to improve the transmission success probability. On the other hand, for a destination terminal that is short in distance from its own wireless transmission device, the received signal level at the destination terminal is expected to be large and the C / N is also expected to be large, so a line with relatively poor communication quality is allocated. However, the transmission success probability does not decrease. Therefore, it is preferable to estimate the distance between the own wireless transmission device and the destination terminal based on the level of the received signal from the destination terminal, and to allocate a line having a required communication quality according to the estimated distance.

Further, the required communication quality may be set according to a request from the destination terminal. That is, since the required communication quality differs depending on the type of data handled by the destination terminal, such as voice, image, data, etc., the wireless transmission device side grasps this, and accordingly, a line of the required communication quality is obtained. May be assigned.

The modulating means includes a multi-level QAM modulating means, and the distance between adjacent signal points on the IQ plane is unevenly arranged to provide a difference in the discrimination quality on the receiving side, thereby improving the communication quality. Different lines can be set up.

In the multi-level QAM modulating means, the arrangement of the signal points on the IQ plane is such that the inter-quadrant distance d1 between the quadrants on the plane is set larger than the inter-quadrant distance d2 within the quadrant, and the quadrant is identified. It is desirable to include means for allocating bits for performing communication to a line having high communication quality and allocating bits for distinguishing signal points within a quadrant to a line having low communication quality. The multi-level QAM modulator may be a 16QAM modulator. As a result, the receiving side can easily distinguish between a line with high communication quality and a line with low communication quality.

[0021] A second aspect of the present invention is a radio communication apparatus, comprising: one radio base station; and a plurality of radio terminals that communicate with the radio base station.
A wireless transmitting apparatus of the present invention, a wireless receiving apparatus that receives a signal from the wireless terminal, and automatically assigns a line assignment for each communication quality according to signal quality from the plurality of wireless terminals received by the wireless receiving apparatus. And means for performing the following.

This makes it possible to transmit data to a plurality of wireless terminals at the same time when transmitting data from one wireless base station to a plurality of wireless terminals by the TDMA method. Therefore, transmission efficiency can be improved and transmission capacity can be increased. Further, the transmission success probability of transmission data can be increased. Thereby, the signal transmission quality can be improved. Further, it is possible to reduce the capacity of the transmission buffer of the wireless base station that stores the transmission waiting data. Further, the number of wireless terminals that can communicate with one wireless base station can be increased.

A third aspect of the present invention is a hierarchical modulation method in which individual information addressed to a plurality of terminals is logically assigned to lines having different communication qualities and multiplexed and modulated simultaneously on one carrier.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a block diagram of a main part of a wireless base station according to an embodiment of the present invention. Figure 2 shows hierarchical 16QAM
FIG. 3 is a diagram showing a signal point arrangement of FIG.

In the embodiment of the present invention, the radio transmitting apparatus of the present invention is applied to a radio base station. That is, as shown in FIG. 1, the present invention relates to a radio base station, which is a modulation means for simultaneously multiplex-modulating information of N lines on which individual communication information for a plurality of N destination radio terminals is transmitted to one carrier. The wireless base station includes a certain hierarchical modulation circuit 15.

Here, a feature of the present invention is that a plurality of types of lines having different communication qualities are set in the hierarchical modulation circuit 15, and a line is allocated to each destination wireless terminal according to the required communication quality. Receiving level measuring unit 13 as a means,
It includes a terminal information storage unit 16 and a buffer control unit 19.

The required communication quality is set according to the distance between the destination wireless terminal and the own wireless base station, and includes a reception level measuring unit 13 which is means for detecting a signal level received from the destination wireless terminal. The terminal information storage unit 16 estimates the distance based on the reception signal level detected by the reception level measurement unit 13. Alternatively, the required communication quality is set according to a request of the destination wireless terminal.

At this time, the buffer control unit 19 automatically performs channel assignment for each communication quality according to the signal qualities from a plurality of terminals.

The hierarchical modulation circuit 15 performs multi-level QAM modulation, arranges the distance between adjacent signal points on the IQ plane non-uniformly, and provides a difference in the discrimination quality on the receiving side to thereby improve the communication quality. A different line is set.

As shown in FIG. 2, in the arrangement of the signal points on the IQ plane, the inter-quadrant distance d1 between the quadrants on the plane is set to be larger than the inter-signal distance d2 within the quadrant, and the quadrant is identified. Bits for high-quality communication,
Bits for discriminating signal points in the quadrant are allocated to a line having low communication quality. Also, the multi-level QAM modulation is 16
QAM modulation.

[0031]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described. FIG. 3 is a diagram showing a configuration example of a transmission frame used for transmitting data between the radio base station and the radio terminal according to the embodiment of the present invention. This example corresponds to the transmission frame in the conventional TDMA system shown in FIG. 8 described above, and shows an example in which a wireless base station can simultaneously transmit to two wireless terminals. is there. Data addressed to the two wireless terminals is hierarchically multiplexed into two signals of a high quality channel and a low quality channel having different qualities realized by the hierarchical modulation scheme, and is transmitted simultaneously.

The number of wireless terminals that can transmit simultaneously is determined by the number of layers of the applied hierarchical modulation scheme. When the number of multiplexes is equal to or more than the number of layers of the hierarchical modulation scheme, a time-divided slot configuration is adopted as in the conventional TDMA scheme as shown in FIG. Here, the data slot is divided into two according to the hierarchy, and is further divided temporally into two, thereby forming a total of four slots.

Next, the hierarchical modulation method will be described. The hierarchical modulation scheme is a modulation scheme capable of hierarchically multiplexing and transmitting signals having different transmission qualities. FIG. 4 is a diagram showing an example of the signal point arrangement of the hierarchical 16QAM.
The four-digit number in FIG. 4 indicates a 4-bit code assigned to each signal point. The upper two bits of each number correspond to the quadrant in which each signal point is located, and the lower two bits correspond to the position of the signal point in each quadrant.

In general, the greater the distance between signal points, the higher the resistance to noise. Therefore, for the upper two bits, the distance between codes is large, resistance to noise is high, and transmission at a low C / N is possible, but for the lower two bits, the distance between codes is small, and A higher C / N is required as compared with 2 bits. Therefore, by assigning the information on the high quality channel side to the upper 2 bits and the information on the low quality channel side to the lower 2 bits, the number of layers 2
Can be hierarchically modulated.

As described above, the hierarchical modulation scheme has a different noise immunity depending on the bit to which the information is assigned, thereby enabling a signal of different transmission quality to be hierarchically multiplexed and transmitted. It is. By devising the signal point arrangement and the bit allocation method, 3
It is also possible to have the above number of layers.

As shown in FIG. 1, the radio base station includes a radio transmission / reception section 12 for receiving a signal transmitted by a radio terminal, a reception level measurement section 13 for measuring a reception level of a signal received by the radio transmission / reception section 12, and A demodulation circuit 17 for demodulating source terminal information and data from a signal received by the radio transmission / reception unit 12
A terminal information storage unit 16 for storing the source terminal information demodulated by the demodulation circuit 17 and the reception level of the signal including the transmission terminal information measured by the reception level measurement unit 13; A buffer control unit 19 for determining the transmission quality of the transmission data addressed to the wireless terminal; a transmission buffer 18 for temporarily storing the transmission data addressed to the wireless terminal and layering and outputting the transmission data according to the transmission quality determined by the buffer control unit 19; It comprises a hierarchical modulation circuit 15 that hierarchically modulates data output from the transmission buffer 18 and a radio transmission / reception unit 12 that transmits a modulation signal output from the hierarchical modulation circuit 15.

The transmission buffer 18 has the same output as the number of layers of the hierarchical modulation scheme to be applied, and the buffer control unit 19 in the data in the buffer in order from the data input first.
Is output to the hierarchical modulation circuit 15 so as to be modulated with the transmission quality determined by the above.

FIG. 4 is a block diagram of a main part of the hierarchical modulation circuit 15. The hierarchical modulation circuit 15 includes, for example, a mapping circuit 31 and a quadrature modulator 32 as shown in FIG.

FIG. 5 is a block diagram of a main part of a wireless terminal according to an embodiment of the present invention. The radio terminal includes a radio transmission / reception unit 22 for receiving radio waves transmitted by the radio base station, a hierarchical demodulation circuit 24 for demodulating a signal received by the radio transmission / reception unit 22, a temporary storage of demodulated data destination information and data, and a data destination. A reception buffer 26 for outputting only data addressed to the own wireless terminal based on the information, a transmission buffer 28 for temporarily storing transmission data and adding transmission source terminal information to the transmission data and outputting the data, and a data output from the transmission buffer 28 And a radio transmission / reception unit 22 for transmitting a modulation signal output from the modulation circuit 25.

The source terminal information addressed to the radio base station to be added to the data in the transmission buffer 28 is, when there is information identifying the radio terminal in the radio base station or information on the communication quality required by the radio terminal, the information. is there.

FIG. 6 is a block diagram of a main part of the hierarchical demodulation circuit 24. The hierarchical demodulation circuit 24 includes a quadrature demodulator 33 and a discrimination circuit 34, as shown in FIG.

FIG. 7 is a flowchart showing a data transmission procedure according to the embodiment of the present invention. The data transmission procedure according to the embodiment of the present invention will be described with reference to FIGS. In the wireless base station, the reception level measurement unit 13 measures the signal level each time the radio transmission / reception unit 12 receives a signal from a wireless terminal, and outputs the signal level to the terminal information storage unit 16. The demodulation circuit 17 demodulates the received signal, extracts source terminal information included in the demodulated signal, and outputs this to the terminal information storage unit 16. The terminal information storage unit 16 updates the latest reception level and terminal information for each wireless terminal (S1 to S5).

The transmission buffer 18 receives and temporarily stores data to be transmitted from the radio base station to the radio terminal, and outputs the data to the hierarchical modulation circuit 15. However, the output to the hierarchical modulation circuit 15 is based on a command from the buffer control unit 19.

The buffer control unit 19 includes the hierarchical modulation circuit 15
The destination wireless terminal of the data to be output to the terminal information storage unit 16 is recognized, and the hierarchy of the output data is determined based on the terminal information stored in the terminal information storage unit 16, and the hierarchical modulation circuit 15 Instruct the transmission buffer 18 to output.

Here, the first method of layering is to use the latest signal reception level as terminal information and assign the data to the high-quality signal layer in order from the data addressed to the wireless terminal having the lower reception level. It is. Generally, a wireless terminal having a low received signal level is located at a point far from the wireless base station, and a large wireless terminal is located at a point near the wireless base station. The reception level is low, and data for a wireless terminal generally located far from the wireless base station is allocated to a high-quality signal and transmitted with high resistance to noise, whereby the transmission path between the wireless terminal and the wireless base station is increased. Is somewhat poor, the transmission success probability can be increased.
In addition, data to a wireless terminal having a high reception level and generally located near a wireless base station can be converted to a signal of a somewhat low quality because the transmission path between the wireless terminal and the wireless base station is relatively good. Even if assignment transmission is performed, the probability that the transmission success probability decreases is small.

The second method of layering is that, when the communication quality required for each wireless terminal differs, such as voice, image, and data, information on the communication quality requested by the wireless terminal is transmitted to the wireless base station. This is hierarchization in which a station manages the information and uses the information as wireless terminal information, and assigns it to a layer of a high quality signal in the order of the required quality.

The hierarchical modulation circuit 15 has the configuration shown in FIG. 4, and uses the data output from the transmission buffer 18 to
The mapping circuit 31 performs hierarchical mapping on a complex plane including the I and Q axes, and quadrature modulates the signal output from the mapping circuit 31 with the quadrature modulator 32.

The signal output from the hierarchical modulation circuit 15 is
After being frequency-converted into a transmission frequency band by the radio transmission / reception unit 12, the radio wave is transmitted from the antenna 11 to the radio terminals in the communication zone of the radio base station as radio waves (S6 to S9).

In the wireless terminal, a radio wave from the radio base station is received by the antenna 21, a signal of a required frequency band is extracted by the radio wave transmitting / receiving section 22, and output to the hierarchical demodulation circuit 24.

The hierarchical demodulation circuit 24 has the configuration shown in FIG. 6, and demodulates the signal input by the quadrature demodulator 33, inputs the demodulated signal to the discrimination circuit 34, and demodulates the hierarchically multiplexed data. Then, the data is output to the reception buffer 26.

The reception buffer 26 temporarily stores the demodulated data, and outputs the data in accordance with an instruction from the buffer control unit 27. The buffer controller 27 recognizes the destination wireless terminal of the data stored in the reception buffer 26, and instructs the reception buffer 26 to output only the data addressed to the terminal itself (S10 to S13). Data transmission from the wireless base station to the wireless terminal is performed as described above.

[0052]

As described above, according to the present invention,
In the case where data is transmitted from one wireless base station to a plurality of wireless terminals by the TDMA method, the problem that conventionally only data addressed to only one wireless terminal can be transmitted at the same time has been solved. By assigning data addressed to a plurality of wireless terminals to different bits of a modulation symbol to form a hierarchy and superimposing and transmitting the signals with signals of different qualities, it is possible to simultaneously transmit to a plurality of terminals in one slot.

Further, according to the present invention, in the radio base station, based on the stored reception level of the signal transmitted last from the radio terminal and information on the communication quality required by each radio terminal, By layering the transmission data and transmitting it to the wireless terminal, the transmission success probability of the transmission data can be increased, the signal transmission quality such as data transmission delay and transmission quality can be improved, and the transmission efficiency can be improved. There is an effect that it can be improved. Further, there is an effect that it is possible to reduce the capacity of the transmission buffer of the wireless base station for storing the transmission waiting data.

According to the present invention, the number of wireless terminals capable of communicating with one wireless base station can be increased and the transmission capacity can be increased due to the effects described above. is there.

[Brief description of the drawings]

FIG. 1 is a block diagram of a main part of a wireless base station according to an embodiment of the present invention.

FIG. 2 is a diagram showing a signal point arrangement of hierarchical 16QAM.

FIG. 3 is a diagram showing a configuration example of a transmission frame used for transmitting data between a radio base station and a radio terminal according to the embodiment of the present invention.

FIG. 4 is a diagram showing a signal point arrangement of hierarchical 16QAM.

FIG. 5 is a block diagram of a main part of the wireless terminal according to the embodiment of the present invention.

FIG. 6 is a block diagram of a main part of a hierarchical demodulation circuit.

FIG. 7 is a flowchart showing a data transmission procedure according to the embodiment of the present invention.

FIG. 8 is a diagram showing an example of a transmission frame for transmitting data between a wireless base station of the TDMA scheme and the reservation scheme and each wireless terminal.

[Explanation of symbols]

 11, 21 Antenna 12, 22 Radio wave transmitting / receiving unit 13 Reception level measuring unit 14, 23 Switch 15 Hierarchical modulation circuit 16 Terminal information storage unit 17 Demodulation circuit 18, 28 Transmission buffer 19, 27 Buffer control unit 20, 26 Reception buffer 24 Hierarchical demodulation Circuit 25 Modulation circuit 31 Mapping circuit 32 Quadrature modulator 33 Quadrature demodulator 34 Discrimination circuit

Claims (7)

[Claims] 1. A radio transmitting apparatus comprising: a modulator for simultaneously multiplex-modulating information on N lines on which individual communication information for a plurality of N destination terminals is transmitted to one carrier wave; A wireless transmission apparatus comprising: means for setting lines having different communication qualities; and allocating a line for each destination terminal according to the required communication quality. 2. The required communication quality is set in accordance with a distance between the destination terminal and the own radio transmitting apparatus, and is detected by a means for detecting a signal level received from the destination terminal, and by the detecting means. 2. The radio transmitting apparatus according to claim 1, further comprising: means for estimating the distance based on the received signal level. 3. The wireless transmission device according to claim 1, wherein the required communication quality is set according to a request from the destination terminal. 4. The communication means according to claim 1, wherein said modulating means includes a multi-level QAM modulating means, and the distance between adjacent signal points on an IQ plane is unevenly arranged to provide a difference in identification quality on a receiving side. The wireless transmission device according to claim 1, wherein lines of different qualities are set. 5. The multi-level QAM modulating means, wherein arrangement of signal points on the IQ plane is such that a signal distance d1 between quadrants on the plane is set to be larger than a signal distance d2 within the quadrant. 5. The radio transmitting apparatus according to claim 4, further comprising means for allocating a bit for identifying a channel to a line with high communication quality and allocating a bit for distinguishing a signal point in a quadrant to a line with low communication quality. 6. The multi-level QAM modulating means comprises 16 QAM
The wireless transmission device according to claim 5, which is a modulation unit. 7. A wireless base station, comprising: a plurality of wireless terminals that mutually communicate with the wireless base station; wherein the wireless base station includes a wireless transmission device according to claim 1;
A wireless receiving device that receives a signal from the wireless terminal; and a unit that automatically performs channel allocation for each communication quality according to signal quality from the plurality of wireless terminals received by the wireless receiving device. A wireless communication device characterized by the above-mentioned.