JP5167615B2 - Wireless communication system, base station apparatus and mobile terminal apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable a terminal to receive data even when the terminal can not acquire MAP information of a header. <P>SOLUTION: In a radio communication system where a base station and a plurality of mobile terminals TA communicate data with each other, the base station allocates a communication area in a frame to a mobile terminal in a transmission waiting state, transmits a header including communication area allocation information, and further transmits a transfer data signal to a mobile terminal allocated to each communication area in a frame of a down link in the communication area, and the mobile terminal acquires the communication area allocation information and receives the transfer data in the allocated communication area in the frame of the down link. Further, the base station allocates the same communication area to at least some of mobile terminal devices in transmission waiting states repeatedly for a plurality of frames, and the mobile terminal devices try to receive transmission data in a frame of a down link dFM based on communication area allocation information in a frame having been received when the mobile terminal devices can not acquire the communication area allocation information. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a radio communication system, a base station apparatus, and a mobile terminal apparatus, and more particularly, radio communication capable of receiving and transmitting data even when the mobile terminal apparatus cannot acquire communication area allocation information from a received signal. The present invention relates to a system, a base station apparatus, and a mobile terminal apparatus.

  In wireless communication between a base station apparatus (hereinafter simply referred to as a base station) and a mobile terminal apparatus (hereinafter simply referred to as a terminal), a frequency band for data communication is provided to each terminal so that a plurality of terminals can communicate with each other. A communication area consisting of a time zone is allocated. This communication area allocation is usually performed by the base station for each frame of the downlink from the base station to the terminal and the uplink in the opposite direction. Then, the base station inserts MAP information that is allocation information of the communication area into the header of the frame and transmits it to all terminals in the cell. At the terminal, the MAP information is acquired, the communication area assigned to each terminal is referred to, data of the assigned communication area is received in the downlink frame, and the assigned communication area is received in the uplink frame. Send data.

  The header including the MAP information is transmitted from the base station every 5 milliseconds, for example, and rewritten every frame. The base station selects an appropriate terminal from among the terminals waiting for communication and assigns the communication area to a plurality of communication areas in the frame in order to give equal communication opportunities to the terminals in the cell.

Such a wireless communication system is described in, for example, Patent Documents 1, 2, and 3.
JP 2000-316182 A JP 2000-68985 A JP-A-2005-151383

  The base station transmits the header including the MAP information by a noise-resistant modulation method and a noise-resistant error correction coding method. By doing so, all the terminals in the cell can normally receive the MAP information in the header.

  However, depending on the terminal, the MAP information may not be normally received. If the MAP information cannot be received, the communication area assigned to the user cannot be acquired, and therefore the data addressed to the user included in the frame cannot be received. As a result, communication efficiency is reduced.

  According to a technique called HARQ in wireless communication, when an error is detected after decoding of an error correction code in received data, the same data is transmitted again, and the previously received data and the received data are combined again. Thus, the transmitted data can be recovered even in a noisy environment. However, although this HARQ can be used for a payload (normal data) that is allowed to be retransmitted, the contents of the header including the MAP information are changed every time, so it is not possible to recover the data using the HARQ technology. Can not.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a radio communication system, a base station apparatus, and a mobile terminal apparatus that can increase the possibility of normal reception without discarding the payload even when communication area allocation information cannot be normally received. It is in.

To achieve the above object, according to a first aspect of the present invention, in a wireless communication system for performing data communication between a base station apparatus and a plurality of mobile terminal apparatuses,
The base station apparatus allocates a communication area in a frame to a mobile terminal apparatus waiting for transmission, transmits a header including the communication area allocation information to the plurality of mobile terminal apparatuses, and further transmits each header in a downlink frame. In the communication area, send a transfer data signal to the mobile terminal device assigned to the communication area,
The mobile terminal apparatus receives the header to obtain the communication area allocation information, receives a transfer data signal of the allocated communication area in a downlink frame, and receives the allocated data in an uplink frame. Send data signal in the communication area
Further, the base station apparatus repeatedly allocates the same communication area to at least some of the mobile terminal apparatuses waiting for transmission over a plurality of frames, and the mobile terminal apparatus receives the communication area allocation information when it cannot acquire the communication area allocation information. The transmission data in the downlink frame is attempted to be received based on the communication area allocation information of the completed frame.

  In the first aspect, according to a preferred embodiment, the base station apparatus has a second reception sensitivity that is worse than the first reception sensitivity than the first mobile terminal apparatus having the first reception sensitivity. The same communication area is repeatedly assigned preferentially to the mobile terminal apparatus.

Further, in the first aspect, according to a preferred embodiment, when the base station apparatus repeatedly assigns the same communication area to the mobile terminal apparatus over a plurality of frames, the base station apparatus assigns the repetitive assignment information to the communication area assignment information. Transmitted to the mobile terminal device,
When the mobile terminal apparatus acquires the repetitive allocation information, the mobile terminal apparatus cannot acquire the communication area allocation information in the subsequent header. The transmission data signal is transmitted in the communication area.

  More preferably, the base station apparatus and the at least some of the mobile terminal apparatuses waiting for transmission perform negotiation communication in advance, and decide to repeatedly allocate the same communication area over a plurality of frames, and the base station apparatus The communication area allocation information corresponding to the determined mobile terminal apparatus is not included in the header.

  Further, in the first aspect, according to a preferred embodiment, the base station device, when repeatedly assigning the same communication area to the mobile terminal device waiting for transmission over a plurality of frames, a plurality of frames that are continuous at a predetermined cycle. The same communication area is repeatedly allocated over the entire area.

  Even if a mobile terminal in a noisy environment cannot obtain the MAP information in the header, it can receive the forwarded data signal in the downlink or transmit the transmission data signal in the uplink. It is possible to suppress a decrease in communication efficiency.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the technical scope of the present invention is not limited to these embodiments, but extends to the matters described in the claims and equivalents thereof.

  FIG. 1 is a diagram showing an overall configuration of a radio communication system to which the present embodiment is applied. The base station apparatus MT performs radio communication with a plurality of mobile terminal apparatuses TA, TB, TC, and TD located in a cell CELL that is an area within a predetermined distance from the base station apparatus MT. In order to perform radio communication with a plurality of terminals in a cell, the base station apparatus MT uses a specific frequency band and a specific time band for a terminal that needs communication in a frame having a plurality of frequency bands and a predetermined time length. Allocate a communication area. Thereby, communication can be performed in parallel with a plurality of terminals in one frame period.

  In the cell CELL in FIG. 1, for example, a terminal TB that is far from the base station apparatus MT has a strong noise and an unfavorable communication state. Therefore, the terminal TB may not be able to normally acquire the communication area allocation information (MAP information) in the received header.

  FIG. 2 is a configuration diagram of the base station apparatus according to the present embodiment. The base station apparatus includes a signal processing unit 11 that generates transmission data to be transmitted and processes reception data, error encoding means 12 that encodes transmission data to be transmitted by a predetermined error encoding method, and Modulation means 13 for modulating with a predetermined modulation method such as QPSK or 16QAM, and a transmitting side radio device 14 for transmitting the modulated data signal from the antenna 15 are provided. Furthermore, the base station apparatus receives the radio signal received by the antenna 15, the receiving side radio apparatus 16, the demodulating means 17 for demodulating it with the same modulation system as the transmitting side, and the error coding system same as the transmitting side. Error decoding means 18 for decoding. The signal processing unit 11 communicates with another base station apparatus (not shown) via the communication line 19. The base station apparatus includes a base station control unit 10 that performs overall control, and includes a computer, its control program, a work memory device, and the like.

  The base station control unit 10 performs control for assigning communication areas to a plurality of terminals that require communication within a cell, control for re-transferring data when an error occurs in received data in the terminal device, and other components. Control elements.

  FIG. 3 is a configuration diagram of the mobile terminal apparatus according to the present embodiment. The mobile terminal apparatus has the same configuration as the base station apparatus of FIG. That is, the signal processing unit 21, the error encoding unit 22, the modulation unit 23, the transmission side wireless device 24, the antenna 25, the reception side wireless device 26, the demodulation unit 27, the error encoding unit 28, Terminal control unit 20. The terminal control unit 20 acquires the MAP information in the header transmitted from the base station apparatus, detects the frequency band and time band of the communication area assigned to itself, the modulation scheme, and the error correction scheme, Control the components. Further, when an error is detected in the received data of the payload, the terminal control unit 20 controls to send a signal requesting the base station to transmit the same data again.

  FIG. 4 is a diagram showing a conventional problem. FIG. 4A shows a normal state, and FIG. 4B shows an abnormal state. FIG. 4A shows a communication area when two frames FM1 and FM2 are transmitted and received in time series. The communication area is specified by the frequency band f on the vertical axis and the time band T on the horizontal axis, and a plurality of communication areas are included in each frame. Each frame transmits a header HD that is transmitted from the base station to the terminal and stores management information, a downlink frame dFM that transmits normal data from the base station to the terminal, and normal data from the terminal to the base station. It consists of an uplink frame upFM. FIG. 4A shows a case where the base station and the terminal TA perform wireless communication.

  The base station and a plurality of terminals operate in frame synchronization, and the base station determines the communication area (frequency band and time band) in the downlink frame and the communication area in the uplink frame for terminals that need to communicate. The allocation information is included in the header HD as MAP information MAP and transmitted to the terminals in the cell. This MAP information MAP includes, for example, a frequency band fa, a time band Ta, a modulation scheme a, and an error coding scheme a for the terminal TA as shown in the figure.

  Then, in the downlink frame dFM, the base station transmits a data signal to be transferred to the terminal to which it is assigned in each communication area. Therefore, in the downlink frame dFM, transfer data signals are not redundantly transmitted to different terminals.

  On the other hand, a plurality of terminals in the cell simultaneously receive this header HD. Since the header HD includes management information necessary for wireless communication in the frame, the header HD is transmitted by a noise-resistant modulation method and error correction coding method. Each terminal, in accordance with the communication area allocation information MAP in the header HD, the frequency band and time band in the downlink frame, the modulation scheme, the error correction coding scheme, the frequency band and time band in the uplink frame, and the modulation The system and error correction coding system are detected.

  The terminal TA to which the frequency band is assigned receives a data signal transferred in the communication area in the MAP information in the downlink frame dFM, and transmits a transmission data signal in the communication area in the map information in the uplink frame upFM. To do.

  In order to enable a large number of terminals in a cell to perform wireless communication in a limited communication area, the base station changes the allocation of the communication area in each frame for each frame. For example, when more terminals require communication, each communication area of each frame is assigned to those terminals in consideration of the data amount. Therefore, the same communication area is not always assigned to the same terminal every frame. In FIG. 4A, a communication area is assigned to the terminal TA in the frames FM1 and FM2, but the assigned communication areas are different between the frames FM1 and FM2. Therefore, the terminal needs to receive the header preceding it for each frame and grasp the presence / absence of assignment of the communication area and the assigned communication area. If the information of the communication area assigned to itself cannot be acquired, it is not known which communication area in the downlink frame should receive the transfer data signal and in which communication area in the uplink frame the transmission data signal should be transmitted. Because.

  As shown in FIG. 4B, in the frame FM1, the terminal TA can normally acquire the header information and can receive and transmit the downlink frame dFM and the uplink frame upFM, but the next frame FM2 In this case, the terminal TA cannot normally acquire the header information, and therefore cannot acquire information on the communication area allocated in the subsequent downlink frame dFM and the uplink frame upFM, and cannot receive and transmit in each frame. . For this reason, the terminal TA has to discard the payload of the frame FM2 and needs to redo its communication, leading to a reduction in communication efficiency.

  FIG. 5 is a diagram illustrating the first embodiment. In order to prevent a decrease in communication efficiency shown in FIG. 4, in this embodiment, the base station reduces the frequency of changing the allocation of communication areas to each terminal. In other words, the base station repeatedly allocates the same communication area over a plurality of frames to at least some of the mobile terminal devices waiting for transmission. That is, the communication area assigned to the terminal TA in the frame FM1 in FIG. 5 is assigned to the terminal TA in the next frame FM2. Thus, by reducing the frequency of changing the allocation of the communication area to the terminal, when the terminal fails to decode the MAP information in the header, the terminal transmits the data signal of the same communication area as the previous frame to the data signal addressed to itself. It is possible to increase the possibility of successful reception by assuming that it is received. As a result, communication efficiency can be improved as a whole.

  In FIG. 5, the same communication area is allocated to the terminal TA in the frames FM1 and FM2. In the frame FM1, the terminal TA normally acquires the MAP information in the header HD and normally acquires the transfer data addressed to itself. In this case, if the terminal TA cannot acquire the MAP information in the header HD in the frame FM2, the downlink frame dFM is used in the communication area, the modulation scheme, and the error correction coding scheme based on the MAP information acquired in the frame FM1. The received data signal is received, demodulated, and error correction decoded. As a result of demodulation and error correction decoding, even if an error is not detected in the transfer data, there is a possibility that it is not the transfer data addressed to itself. Therefore, the transfer destination address in the header in the acquired packet 30 is confirmed. It is confirmed whether or not. If it is addressed to itself, the transfer data is acquired, and if it is not addressed to itself, it is discarded.

  As described above, since the base station reduces the frequency of changing the allocation of the communication area to each terminal, the terminal TA can acquire the MAP information in the frame FM2 even if it cannot acquire the MAP information in the frame FM2. Thus, by attempting to receive the transfer data in the downlink frame dFM, the possibility of successful reception is increased, and a decrease in communication efficiency can be suppressed. When the downlink frame dFM attempts to receive the transfer data on the assumption that the same communication area is allocated, and it is confirmed that the transfer data cannot be received successfully even if the reception is not successful. The reception processing is only wasted, and it does not affect other terminals. However, in the uplink frame upFM, if transmission is attempted on the assumption that it is assigned to the same communication area, it will compete with transmissions of other terminals if that assumption is not correct. Therefore, it is not preferable to attempt transmission based on the above assumption in transmission in an uplink frame.

  FIG. 6 is a flowchart of base station transmission area allocation processing. FIG. 6 shows a process of assigning which terminal to one communication area in a predetermined frequency band and time band in the frame. One frame is divided into finite, for example, 16 fixed communication areas.

  First, while there is no transmission waiting data (NO in S12), the waiting state S10 continues. When transmission-waiting data is generated (YES in S12), the base station control unit 10 of the base station selects a transmission-waiting terminal to be allocated to the communication area based on a predetermined priority (S14). For example, a higher priority is given to a terminal having a small amount of transmission data during a certain time, and a lower priority is given to a terminal once selected. By adopting such priorities, wireless communication between a larger number of terminals and base stations is possible in a limited communication area.

  Then, the priority of the selected terminal is changed, for example, changed to the lowest order (S16). When communication is started (S18) and one frame of data is transmitted / received (S20), while there is untransmitted data (YES in S22), until a prescribed number of frames (for example, eight consecutive times) is reached. (NO in S24), the data transmission / reception is executed without changing the selection of the terminal assigned to the communication area (S20). Then, when there is no untransmitted data (NO in S22) or when the specified number of frames is reached (YES in S24), the assignment of the terminal to the communication area is canceled (S26).

  As described above, the base station assigns a terminal waiting for communication to each communication area, and does not cancel the assignment over a predetermined number of frames for the once assigned terminal. Therefore, the frequency of changing the allocation of communication areas to terminals can be reduced. The reception process at the terminal will be described in detail later.

  FIG. 7 is a diagram illustrating HARQ at a terminal. According to HARQ (Hybrid Automatic Repeat reQuest), when an error is detected as a result of error correction decoding of the received data signal and cannot be corrected, the same received data is retransmitted, and the received data received again and the received data received earlier are received. The correct received data is restored by combining the data. In FIG. 7, even if an error (black part) is detected in 4 bits in the first received data string 41 and a 4-bit error is detected in the second received data string 42, a data string 43 obtained by synthesizing them. Only one bit remains in the. An error bit can be eliminated by storing the combined data string 43 in a memory and receiving the same data string again.

  However, since this HARQ technique eliminates error bits by synthesizing the received data transmitted to itself, the result of receiving the transfer data in the same communication area as the previous frame assuming that it is addressed to itself. When an error bit is detected, it is not preferable to store the data string 43 synthesized therefrom in a memory. Therefore, in the present embodiment, the composite data string is not stored in the memory in the HARQ technique.

  FIG. 8 is a diagram illustrating the second embodiment. In the first embodiment described above, the same communication area is repeatedly assigned to at least some terminals in the cell. In the second embodiment, the same communication area is repeatedly allocated over a plurality of frames to a terminal having a poor communication state. Further, the same communication area is repeatedly assigned to a terminal having a poor communication state more times than a terminal having a good communication state. That is, the frequency of changing the communication area is set lower for terminals with poor communication status. As a result, for the terminal having a high probability of not being able to acquire the MAP information in the header due to a poor communication state, an attempt was made to receive the transfer data signal in the communication area of the MAP information acquired in the previous frame when the MAP information could not be acquired. The reception failure rate at the time can be lowered. Therefore, it is possible to suppress the probability that the process of attempting to receive without acquiring the MAP information is wasted.

  In FIG. 8, it is assumed that the reception status of the terminal TB among the terminals TA, TB, and TC in the cell is lower than the other terminals TA and TC. Since the reception sensitivity of the terminal can be measured by a terminal noise reception rate (CINR) or the like, the base station apparatus can know a terminal having poor reception sensitivity. Therefore, the base station repeatedly assigns the same communication area preferentially to the terminal TB having poor reception sensitivity. As shown in FIG. 8, the same communication area is allocated to the terminal TB in the frames FM1 and FM2, but different communication areas are allocated to the other terminals TA and TC. Since the terminals TA and TC have a low probability of not acquiring MAP information, reception and transmission can be successful even if the allocation area is different for each frame, but the terminal TB has a high probability of not acquiring MAP information, but the same Since it is repeatedly assigned preferentially to the area, it can be successfully received by the method according to the first embodiment.

  FIG. 9 is a diagram illustrating a third embodiment. In the first and second embodiments described above, the base station repeats the assignment of the same communication area to at least some terminals a plurality of times to reduce the frequency of changing the communication area. As a result, when the MAP information cannot be acquired, the terminal attempts to receive the MAP information based on the MAP information in the previous frame to improve communication efficiency.

  However, this method can be applied to reception in a downlink frame in which data is transferred from the base station to the terminal, but cannot be applied to transmission in an uplink frame in which data is transferred from the terminal to the base station. This is because in the downlink frame, the base station allocates communication areas to multiple terminals without duplication and only attempts to receive, so even if reception fails, it affects the reception operation of other terminals. It is not given. On the other hand, in an uplink frame, if a terminal that is assumed to have the same MAP information as the previous frame attempts to transmit in a certain communication area, other legitimate terminals to which the communication area is assigned also transmit, so transmission conflicts. Because it will do.

  Thus, in the third embodiment, when the base station repeatedly assigns the same communication area to a terminal over a plurality of frames, the base station adds the repeated information to the MAP information. The repetition information is a parameter bit or a flag bit that guarantees a predetermined number of repetitions of the communication area. Alternatively, it may be repetition number information or infinite repetition allocation information. However, even when infinite repeat assignment is notified, the repeat is canceled within a certain finite time.

  As a result, the terminal can detect in advance that the same communication area is repeatedly assigned, so that even a frame for which MAP information cannot be acquired can transmit a transmission data signal in the same communication area using an uplink frame. . Even so, it is possible to avoid contention with transmissions of other terminals. The terminal also receives the transfer data signal in the same communication area even in the downlink frame.

  As shown in FIG. 9, in the frame FM1, repetition information indicating that the same communication area is assigned to the MAP information in the header HD six consecutive times in the downlink frame dFM and the same communication area four times in the uplink frame upFM. Is added. In that case, even if the terminal TA cannot acquire the MAP information of the header HD in the next frame FM2, the same communication area as the previous frame is allocated in the downlink frame and the uplink frame, and in the subsequent frame, It is guaranteed that the same communication area is allocated for the remaining four times and twice. Therefore, the terminal TA can transmit a data signal even in the uplink frame upFM when the MAP information cannot be acquired.

  When HARQ is adopted between the terminal and the base station, whether or not the base station has been successfully received is added to the MAP information. Therefore, if the terminal cannot acquire the MAP information, it cannot confirm whether the base station has been successfully received. Therefore, it is desirable that the terminal transmits the same data signal as the previous one in the same communication area.

  In the third embodiment described above, the base station does not decide to repeatedly assign the same communication area unilaterally, but performs negotiation communication in advance between the base station and the terminal, so that there is nothing in a session. It may be determined whether to allocate a fixed communication area for a time limit, or to allocate a fixed communication area for a sufficiently long finite number of times (for example, several tens of seconds). When canceling this, negotiation communication is performed again between the base station and the terminal.

  In this way, the negotiation communication enables the terminal to know that the same communication area is repeatedly assigned indefinitely or for a sufficiently long period. Therefore, it is not necessary to include MAP information about the terminal in the HD. By reducing the MAP information, the amount of data that can be included in the payload (normal data) can be increased.

  FIG. 10 is a diagram illustrating a fourth embodiment. In the fourth embodiment, when the same communication area is repeatedly assigned to a terminal over a plurality of frames, the same communication area may be repeatedly assigned over a plurality of frames that are consecutive in a predetermined cycle. As shown in FIG. 10, in the continuous frames FM1 to FM9, the terminals TA, TB, and TC are allowed to communicate with the base station by being assigned a communication area every three frames. On the other hand, the terminal TD is assigned a communication area in every frame. In such a case, the same communication area is repeatedly assigned to the terminal TA in the frames FM1, FM4, FM7. The same applies to the terminals TB and TC. In this way, it is not always necessary to repeatedly assign the same communication area in successive frames.

  When adopting the above-described HARQ to eliminate error bits, it is necessary to transmit and receive a data signal including control information between the base station and the terminal, which may require 2 to 3 frames. Also, the number of terminals that a base station can provide a communication area in one frame is usually smaller than the number of terminals waiting for communication in the cell of the base station. In this case, the base station shifts the frame and allocates a communication area to the terminal waiting for communication. For this reason, a communication area is allocated to a single terminal in frames that are continuous at a certain period. Therefore, the first, second, and third embodiments can be applied even in such a case.

  In that case, it is desirable that the base station adds information on how many frames are allocated to a continuous frame to the MAP information in the header HD and transmits the information to the terminal.

  FIG. 11 is a flowchart showing the control at the terminal in the first to fourth embodiments. When the frame controller succeeds in detecting the synchronization of the frame (YES in S30), the terminal controller 20 demodulates the first header of the frame, performs error correction decoding, and analyzes the MAP information included therein (S32). If no error is detected in the MAP information (YES in S32), the transfer data signal in the communication area defined by the frequency band and time band included in the MAP information is transmitted in the downlink frame according to the normal operation. Demodulation is performed using the modulation method included in the information, and error correction decoding is performed using the error correction coding method included in the information (S34). In addition, the parameter in the MAP information is acquired and updated (S36), and the transmission data is modulated in the communication area included in the MAP information by the uplink frame using the modulation scheme included in the information, and is included in the information. A transmission data signal is transmitted after being encoded by an error correction encoding method.

  If an error is detected in the MAP information and normal information cannot be acquired, the terminal control unit 20 assigns the same communication area in a prior negotiation communication as described in the fourth embodiment. Is determined (S38), and when such fixed area allocation is not determined (NO in S38), the same number of times as described in the third embodiment described above. It is checked whether or not the MAP information indicating that the communication area is repeatedly allocated has been received and within the predetermined number (S40), and if within the effective number (YES in S40), the effective number is updated (reduced). (S42). Further, when fixed allocation is not performed in advance negotiation (NO in S38), and when notification of allocation of the same area is not repeatedly received from the base station (NO in S40), the terminal control unit 20 tries reception with the frame. If it is determined whether or not to try (YES in S44), the process from step S46 is performed. If it is not determined to try (NO in S44), reception in that frame is not performed.

  When the same communication area is fixedly assigned to its own terminal in the negotiation with the base station (YES in S38), or when a predetermined number of repeated assignments are informed from the base station (YES in S40) Or, even if the information is not notified from the base station (YES in S44), the reception process is performed in the current frame based on the MAP information acquired in the previous frame (S48, S56).

  First, when HARQ is not preferentially used (NO in S46), the transfer data signal is received, demodulated, and decoded in the downlink frame in the frequency domain of the previous MAP information, the modulation method, and the error correction coding method. (S48). In particular, when the same communication area is fixedly assigned and when it is repeatedly assigned a predetermined number of times, the terminal succeeds in reception even when the base station has not changed the communication area (YES in S50).

  In addition, when HARQ is preferentially used (YES in S46), the base station may transfer the same data, so the frequency domain of the previous MAP information, the modulation scheme, the error correction coding scheme Then, reception, demodulation, and decoding of the transfer data signal in the downlink frame are performed, and the error is corrected by HARQ combining with the reception data already stored in the memory (S52). That is, a flag indicating that the same data is transferred is included in the MAP information in the header, but since the terminal has not acquired the MAP information, HARQ combining is attempted. If transfer data with no error can be acquired by this HARQ combining, reception is successful (YES in S54). Also, if reception fails in HARQ combining (NO in S54), the base station may not transfer the same data, so the terminal uses the frequency domain, modulation scheme, and error correction coding scheme of the previous MAP information. The transfer data signal is received, demodulated and decoded in the downlink frame (S56).

  As described above, when the base station implicitly assigns the same communication area by decreasing the frequency of change of the communication area for the same terminal as in the first and second embodiments, Even if acquisition of MAP information fails, data reception on the downlink can be successful. Moreover, the possibility of data reception can be further enhanced by combining the fixed allocation of the same communication area and the allocation of the same communication area repeatedly a predetermined number of times as in the third embodiment. In the case of the third embodiment, the terminal can transmit data according to the previous MAP information even in the uplink frame.

  The above embodiment is summarized as follows.

(Supplementary note 1) In a radio communication system that performs data communication between a base station apparatus and a plurality of mobile terminal apparatuses,
The base station apparatus allocates a communication area in a frame to a mobile terminal apparatus waiting for transmission, transmits a header including the communication area allocation information to the plurality of mobile terminal apparatuses, and further transmits each header in a downlink frame. In the communication area, send a transfer data signal to the mobile terminal device assigned to the communication area,
The mobile terminal apparatus receives the header to obtain the communication area assignment information, receives a transfer data signal of the assigned communication area in a downlink frame, and receives the assigned data in an uplink frame. Send data signal in the communication area
Further, the base station apparatus repeatedly allocates the same communication area to at least some of the mobile terminal apparatuses waiting for transmission over a plurality of frames, and the mobile terminal apparatus receives the communication area allocation information when it cannot acquire the communication area allocation information. A wireless communication system, which attempts to receive transmission data in the downlink frame based on communication area allocation information of a completed frame.

(Appendix 2) In Appendix 1,
When the base station apparatus tries to receive the transmission data in the downlink frame based on the communication area allocation information of the received frame, it confirms that the received transfer data is the data addressed to itself. In some cases, the wireless communication system acquires the transfer data.

(Appendix 3) In Appendix 1,
The base station apparatus gives priority to the second mobile terminal apparatus having a second reception sensitivity that is worse than the first reception sensitivity over the first mobile terminal apparatus having the first reception sensitivity. A wireless communication system characterized by repeatedly assigning areas.

(Appendix 4) In Appendix 1,
When the base station apparatus repeatedly assigns the same communication area to the mobile terminal apparatus over a plurality of frames, the base station apparatus adds the repetitive assignment information to the communication area assignment information and transmits it to the mobile terminal apparatus,
When the mobile terminal apparatus acquires the repetitive allocation information, the mobile terminal apparatus cannot acquire the communication area allocation information in the subsequent header. A wireless communication system, wherein a transmission data signal is transmitted in a communication area.

(Appendix 5) In Appendix 4,
The wireless communication system, wherein the repetitive assignment information includes repetitive assignment number information or indefinite repetitive assignment information.

(Appendix 6) In Appendix 4,
The base station apparatus and the at least some of the mobile terminal apparatuses waiting for transmission perform negotiation communication in advance, and decide to repeatedly assign the same communication area over a plurality of frames. A wireless communication system, wherein communication area allocation information corresponding to a mobile terminal apparatus is not included in the header.

(Appendix 7) In Appendix 1,
When the base station apparatus repeatedly assigns the same communication area to a mobile terminal apparatus waiting for transmission over a plurality of frames, the base station apparatus repeatedly assigns the same communication area over a plurality of frames consecutive in a predetermined cycle. Wireless communication system.

(Appendix 8) In Appendix 1,
The base station apparatus assigns the same modulation scheme and the same error correction coding scheme and allocates the same communication area to a plurality of mobile terminal devices waiting for transmission repeatedly over a plurality of frames. A wireless communication system, wherein the transfer data signal is generated by a modulation method and an error correction coding method.

(Supplementary note 9) A wireless communication system for performing data communication between a base station apparatus and a plurality of mobile terminal apparatuses,
The base station apparatus allocates a communication area in a frame to a mobile terminal apparatus waiting for transmission, transmits a header including the communication area allocation information to the plurality of mobile terminal apparatuses, and further transmits each header in a downlink frame. In the communication area, a transfer data signal is transmitted to the mobile terminal apparatus allocated to the communication area, and the mobile terminal apparatus receives the header to acquire the communication area allocation information, and transmits the communication area allocation information in a downlink frame. In the base station apparatus of a wireless communication system that receives a transfer data signal in an assigned communication area and transmits a transmission data signal in the assigned communication area in an uplink frame,
If the same communication area is repeatedly assigned to at least some of the mobile terminal devices waiting for transmission over a plurality of frames and the communication area assignment information cannot be obtained for the mobile terminal apparatus, the communication area assignment information of the received frame is used. A base station apparatus of a wireless communication system, characterized in that, based on this, attempts to receive transmission data in the downlink frame.

(Supplementary Note 10) A wireless communication system that performs data communication between a base station device and a plurality of mobile terminal devices,
The base station apparatus allocates a communication area in a frame to a mobile terminal apparatus waiting for transmission, transmits a header including the communication area allocation information to the plurality of mobile terminal apparatuses, and further transmits each header in a downlink frame. In the communication area, a transfer data signal is transmitted to the mobile terminal apparatus allocated to the communication area, and the mobile terminal apparatus receives the header to acquire the communication area allocation information, and transmits the communication area allocation information in a downlink frame. In the mobile terminal device of a wireless communication system for receiving a transfer data signal in an assigned communication area and transmitting a transmission data signal in the assigned communication area in an uplink frame,
The base station apparatus repeatedly assigns the same communication area to at least some mobile terminal apparatuses waiting for transmission over a plurality of frames,
A mobile terminal apparatus of a wireless communication system, wherein when the communication area allocation information cannot be acquired, the transmission data in the downlink frame is tried to be received based on the communication area allocation information of the received frame.

It is a figure which shows the whole structure of the radio | wireless communications system to which this Embodiment is applied. It is a block diagram of the base station apparatus in this Embodiment. It is a block diagram of the mobile terminal apparatus in this Embodiment. It is a figure which shows the conventional subject. It is a figure which shows 1st Embodiment. It is a flowchart figure of the allocation process of the transmission area of a base station. It is a figure which shows HARQ in a terminal. It is a figure which shows 2nd Embodiment. It is a figure which shows 3rd Embodiment. It is a figure which shows 4th Embodiment. It is a flowchart figure which shows the control in the terminal in 1st-4th embodiment.

Explanation of symbols

FM1, FM2: Frame f: Frequency dFM: Downlink frame upFM: Uplink frame HD: Header

Claims (5)

In a wireless communication system that performs data communication between a base station device and a plurality of mobile terminal devices,
The base station apparatus allocates a communication area in a frame to a plurality of mobile terminal apparatuses waiting to be transmitted by changing each frame, and transmits a header including the communication area allocation information to the plurality of mobile terminal apparatuses, Further, in each communication area in the downlink frame, a transfer data signal to the mobile terminal device assigned to the communication area is transmitted,
The mobile terminal apparatus receives the header to obtain the communication area assignment information, receives a transfer data signal of the assigned communication area in a downlink frame, and receives the assigned data in an uplink frame. Send data signal in the communication area
Further, the base station apparatus repeatedly assigns the same communication area to some of the mobile terminal apparatuses over a plurality of frames, and the mobile terminal apparatus cannot acquire the communication area allocation information wireless communication system wherein an attempt to receive the transfer data signal in the frame of the downlink, characterized that you get the transfer data if addressed to itself based on the communication region allocation information of the received frame. In claim 1,
The base station apparatus gives priority to the second mobile terminal apparatus having a second reception sensitivity that is worse than the first reception sensitivity over the first mobile terminal apparatus having the first reception sensitivity. A wireless communication system characterized by repeatedly assigning areas. In claim 1,
When the base station apparatus repeatedly assigns the same communication area to the mobile terminal apparatus over a plurality of frames, the base station apparatus adds the repetitive assignment information to the communication area assignment information and transmits it to the mobile terminal apparatus,
When the mobile terminal apparatus acquires the repetitive allocation information, the mobile terminal apparatus cannot acquire the communication area allocation information in the subsequent header. A wireless communication system, wherein a transmission data signal is transmitted in a communication area. In claim 3,
The base station apparatus and the part of the mobile terminal apparatuses waiting for transmission perform negotiation communication in advance, and decide to repeatedly allocate the same communication area over a plurality of frames, and the base station apparatus A wireless communication system, wherein communication area allocation information corresponding to a terminal device is not included in the header. In claim 1,
When the base station apparatus repeatedly assigns the same communication area to a part of the mobile terminal apparatuses waiting for transmission over a plurality of frames, the base station apparatus repeatedly assigns the same communication area over a plurality of frames consecutive in a predetermined cycle. A wireless communication system.

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