JP4793500B2 - Wireless communication system - Google Patents

Description

  The present invention relates to a radio communication apparatus, and preferably to a radio communication apparatus used in a mobile radio communication system or a wireless LAN system that employs a UMTS (WCDMA) communication system.

  In recent years, data transmission using a shared channel (Shared Channel) capable of switching a data transmission destination according to a situation is actively performed, instead of performing communication by allocating a fixed time slot.

  In a data transmission method using a shared channel, a receiving communication device (referred to as a receiving station) cannot predict when data is transmitted from a transmitting communication device (referred to as a transmitting station). Therefore, the receiving station receives the data transmitted by the transmitting station every time and checks whether the data is transmitted to itself. And if it is sent to itself, it takes the received data, processes it (decode etc.) and outputs it, but if it is not sent to itself, it is necessary to perform decoding etc. There is no output.

  In a data transmission system using a shared channel, there is a case where it is desired to use information from a receiving station when transmitting data.

  For example, when data transmission is performed, adaptive modulation and coding (AMC) is performed.

  Adaptive modulation control is control that adaptively changes the transmission format when performing data transmission.

  For example, the receiving station receives a signal transmitted from the transmitting station, measures the radio environment (downlink radio environment) between the transmitting station and the receiving station using the received signal, and measures the measurement. The result is transmitted to the transmitting station, and the transmitting station adaptively changes the transmission format based on the measurement result. As a change in transmission format, for example, the QPSK modulation method is changed to a 16QAM modulation method, the number of spreading codes used at the time of transmission is changed, and the data size (packet length) to be transmitted is changed. This is a typical example.

  Here, HSDPA (High Speed Downlink Packet Access) will be described as an example of a method for performing data transmission using a shared channel. HSDPA is applied to a UMTS (WCDMA) communication system, and is a method that enables a high-speed packet transmission method using a downlink shared channel. Similarly, in a wireless LAN communication system, a high-speed packet transmission method using a shared channel has been proposed.

  HSDPA employs not only data transmission using the shared channel described above, but also adaptive modulation and coding (AMC).

  Furthermore, HSDPA employs an H-ARQ (Hybrid Automatic Repeat reQuest) system. In H-ARQ, when a mobile station detects an error in received data from a base station, it makes a retransmission request to the base station. Since the base station that has received this retransmission request retransmits the data, the mobile station effectively uses both the already received data and the retransmitted received data. In this way, unnecessary transmission is prevented from occurring by effectively using data that has already been received.

  Next, main radio channels used for HSDPA will be described.

  As channels dedicated to HSDPA, there are HS-SCCH (High Speed-Shared Control Channel), HS-PDSCH (High Speed-Physical Downlink Shared Channel), and HS-DPCCH (High Speed-Dedicated Physical Control Channel).

  HS-SCCH and HS-PDSCH are both shared channels in the downlink direction (that is, the direction from the base station to the mobile station), and HS-SCCH is a parameter related to data transmitted on the HS-PDSCH. Is a control channel for transmitting. The various parameters include, for example, modulation type (Modulation Scheme) information indicating which modulation method to use, the number of spreading codes to be assigned (number of codes), a pattern of rate matching processing to be performed before transmission, etc. Information.

  On the other hand, HS-DPCCH is an individual control channel (Dedicated Control Channel) in the uplink direction (that is, the direction from the mobile station to the base station). For example, it is used by a mobile station when transmitting the result of whether data received from a base station via HS-PDSCH is acceptable or not as an ACK signal and a NACK signal (response signal) to the base station. When the mobile station fails to receive data (when the received data is a CRC error, etc.), a NACK signal as a retransmission request is transmitted from the mobile station, so that the base station performs retransmission control. Become. In addition, when the radio base station cannot receive an ACK signal or a NACK signal (in the case of DTX), it also performs retransmission control, so that the mobile station may enter a DTX state in which neither an ACK signal nor a NACK signal is transmitted. One of them.

In addition, the HS-DPCCH is also used to transmit reception quality information (for example, SIR) of a received signal from the base station measured by the mobile station to the base station as CQI information (Channel Quality Indicator). Then, the base station changes the downlink transmission format according to the received CQI information. In other words, if the CQI information indicates that the downlink radio environment is good, the transmission format is switched to a modulation method capable of transmitting data at a higher speed, and conversely, the CQI information is not good in the downlink radio environment. , The transmission format is switched to a modulation scheme that transmits data at a lower speed (that is, adaptive modulation control is performed).
・ "Channel structure"
Next, a channel configuration in HSDPA will be described.
FIG. 1 is a diagram for illustrating a channel configuration in HSDPA. Since W-CDMA employs a code division multiplexing system, each channel is separated by a code.

First, the channels not described will be briefly described.
CPICH (Common Pilot Channel) is a downlink common channel and is transmitted to all mobile stations in a radio zone (cell).

  The CPICH is a channel used for channel estimation, cell search, and a timing reference for other downlink physical channels in the same cell in a mobile station, and is a channel for transmitting a so-called pilot signal.

  Next, channel timing relationships will be described with reference to FIG.

  As shown in FIG. 1, each channel is composed of 3 × 5 = 15 slots (each slot is equivalent to a length of 2560 chips) to form one frame (10 ms). As described above, since CPICH is used as a reference for other channels, the heads of P-CCPCH (not shown) and HS-SCCH frames coincide with the heads of CPICH frames. Here, the head of the HS-PDSCH frame is delayed by 2 slots with respect to HS-SCCH or the like. However, after the mobile station receives the modulation type information via HS-SCCH, the received modulation type is changed to the received modulation type. This is because HS-PDSCH can be demodulated by a corresponding demodulation method. HS-SCCH and HS-PDSCH constitute one subframe with three slots. The mobile station receives the HS-SCCH every subframe, checks whether data is transmitted to itself, and receives (decodes) the HS-PDSCH if data is transmitted. When data transmission is not performed, HS-PDSCH is not received (decoded).

  HS-DPCCH is an uplink channel for transmitting an ACK / NACK signal, which is a response signal for confirming reception, from a mobile station to a base station after about 7.5 slots have elapsed since reception of HS-PDSCH. The slot to be used (1 slot length) is included.

  The HS-DPCCH is also used to periodically transmit CQI information for adaptive modulation control to the base station. Here, the CQI information to be transmitted is calculated based on, for example, a reception environment (for example, a SIR measurement result of CPICH) measured in a period from 4 slots before to 1 slot before CQI transmission.

  The matter regarding HSDPA mentioned above is disclosed by the following nonpatent literature 1, for example.

3G TS 25.212 (3rd Generation Partnership Project: Technical Specification Group Radio Access Network; Multiplexing and channel coding (FDD)) V6.2.0 (June 2004)

  According to the background art described above, the use efficiency of the channel can be increased by using the shared channel. However, when most of the data received each time is not addressed to itself, for the receiving station, Since HS-SCCH is received every subframe, there arises a problem that power is consumed for useless reception processing.

  This will be briefly described with reference to FIG.

  FIG. 2 shows a transmission / reception sequence in the case of HSDPA.

  FIG. 2 shows only signals transmitted and received between the radio base station (BTS) and one mobile station (MS1). Of course, in the blank portions of HS-SCCH and HS-PDSCH, other mobile A signal may be transmitted to the station.

  As shown in the figure, the MS 1 receives the CPICH that is constantly transmitted from the BTS, and periodically transmits the measurement result to the BTS as a CQI.

  For example, when MS1 transmits CQI in A in the figure, and BTS selects this MS1 as the next data transmission destination, it is transmitted to MS1 in B (C) in the figure. HS-SCCH (HS-PDSCH (DSCH)) is data generated based on this CQI.

  That is, the BTS selects a transmission format corresponding to the CQI, transmits the modulation scheme and spreading code information corresponding to the transmission format on the HS-SCCH, and transmits the HS-PDSCH using the modulation scheme and spreading code. As a result, adaptive modulation control is efficiently performed.

  However, there is a case where there is no data to be transmitted to MS1 (when transmission of data to other MS is prioritized), and if this period is continued, a packet is not transmitted to MS1 as shown in the figure. Periods may occur.

  During this time, the MS 1 is forced to perform useless reception processing (HS-SCCH reception and the like) and transmission processing (CQI transmission and the like), and wastes power.

  Accordingly, one of the objects of the present invention is to reduce the processing load on the communication apparatus (mobile station) when performing data transmission using a shared channel. A further object is to perform adaptive modulation control efficiently while reducing the processing load.

  It is to be noted that the present invention is not limited to the above-described object, and is an effect derived from each configuration shown in the best mode for carrying out the invention described later, and has an effect that cannot be obtained by the conventional technique. Can be positioned as one.

In order to solve the above problems, a wireless communication system having a transmitting station and a receiving station, wherein the receiving station receives data via a shared channel and represents a change in the transmission format of the shared channel. A reception unit that intermittently receives information, and reception quality information that affects the transmission format of the data intermittently at a timing set to be a predetermined time before the timing of intermittent reception performed by the reception unit. further comprising a transmission section that transmits to provide wireless communication system according to claim.

  ADVANTAGE OF THE INVENTION According to this invention, when performing the data transmission using a shared channel, the reduction of the processing load of a communication apparatus (mobile station) can be aimed at.

  Furthermore, adaptive modulation control can be efficiently executed while reducing the processing load.

It is a figure for showing the channel structure in HSDPA. It is a figure for showing the transmission / reception sequence in HSDPA. It is a figure which shows the wireless base station which concerns on this invention. It is a figure which shows the mobile station which concerns on this invention. It is a figure for showing the transmission and reception sequence (the 1) concerning the present invention. It is a figure for showing the cycle (the 1) of transmission and reception concerning the present invention. It is a figure for showing the cycle (the 2) of transmission and reception concerning the present invention. It is a figure for showing the period (the 3) of transmission and reception concerning the present invention. It is a figure for showing the cycle (the 4) of transmission and reception concerning the present invention. It is a figure for showing the mode concerning the present invention. It is a figure for showing the cycle (the 5) of transmission and reception concerning the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[A] Description of First Embodiment In this embodiment, reception for determining whether data received via a shared channel is addressed to the own apparatus is intermittently performed, and the timing of the intermittent reception is determined. Information that affects the transmission format of data received via the shared channel is intermittently transmitted a predetermined time before.

  Thus, reception for determining whether the data received via the shared channel is addressed to the own apparatus is intermittently performed to reduce the processing load (power consumption) and to be transmitted via the shared channel. The data transmission format can be precisely controlled.

  As described above, various types of communication devices (for example, wireless communication devices constituting a wireless LAN system) can be used for data transmission using a shared channel. Here, the HSDPA described above is used. A corresponding wireless communication apparatus will be described as an example.

  In this case, the shared channel corresponds to the HS-PDSCH, the determination as to whether the shared channel is addressed to the own apparatus is performed by receiving the HS-SCCH, and the information that affects the transmission format corresponds to the CQI information.

  FIG. 3 shows a configuration of a radio base station corresponding to HSDPA.

  In the figure, 1 is a radio base station, 2 is a radio transmission / reception unit for transmitting / receiving radio signals to / from a mobile station, 3 is a control unit for controlling each unit, and 4 is a routing device (ATM switch, router, base A first interface unit 5 for interfacing with a station control device or the like) indicates a storage unit for storing data to be transmitted to a mobile station via a shared channel.

  The radio transmission / reception unit 2 includes a CPICH transmission unit 6 which is a CPICH transmission unit for transmitting the mobile station so that the mobile station can measure the quality of the downlink radio channel required for performing adaptive modulation control.

  Moreover, the radio | wireless transmission / reception part 2 is provided with the HS-SCCH transmission process part 7 which performs transmission of HS-SCCH for notifying that data are transmitted via HS-PDSCH which is a shared channel.

  As described above, the HS-SCCH is provided because it is also used to notify the mobile station of information (modulation scheme, spreading code information, etc.) necessary for receiving the HS-PDSCH. However, HS-SCCH can be omitted and data can be transmitted via HS-PSCH suddenly.

  Further, the wireless transmission / reception unit 2 is a channel for transmitting data such as packet data at high speed, and performs HS-PDSCH (DSCH) transmission that controls transmission format according to CQI information. A transmission processing unit 8 is provided.

  In addition, the radio transmission / reception unit 2 includes an HS-DPCCH reception processing unit 9 for receiving CQI information, an ACK signal, and a NACK signal transmitted from the mobile station.

  On the other hand, the control unit 3 includes a MAC-hs transmission processing unit 10 for executing H-ARQ, and a mode determination unit that performs mode determination based on transmission data information such as how much transmission data is present for each mobile station. 11. A notification processing unit 12 that generates a signal (notification signal) for notifying the mobile station of the result of mode determination is provided.

  Next, a mobile station compatible with HSDPA will be described with reference to FIG.

  In the figure, 15 is a mobile station, 16 is a radio transmission / reception unit for transmitting / receiving a radio signal to / from the radio base station 1, 17 is a control unit for controlling each unit, 18 is voice, text, various setting information, etc. 19 is a CQI table indicating the correspondence between the CPICH reception quality and the CQI information, and the reception data (HS-PDSCH is detected in order to realize H-ARQ). The memory | storage part for memorize | storing the data received via the.

  In addition, the wireless transmission / reception unit 16 includes a CPICH reception unit 20, an HS-SCCH reception processing unit 21, an HS-PDSCH reception processing unit 22 provided to correspond to each processing unit of the wireless transmission / reception unit 2 of the wireless base station 1, The HS-PDSCH reception processing unit 23 is shown.

  On the other hand, the control unit 17 includes a MAC-hs processing function unit 24 that performs H-ARQ operation control and the like, an RLC layer processing function unit 25, a mode control function unit 26 that has a function of controlling modes, which will be described later, and the like. ing.

  The above is the description of the configuration of the radio base station and the mobile station related to the present embodiment.

  Next, the operation of these apparatuses will be described with reference to FIG.

  As described above, the control unit 17 of the mobile station 15 includes the mode control function unit 26. When the first mode is set to the mobile station 15 by this, the HS-SCCH of the radio transmission / reception unit 16 is set. The reception processing unit 21 and the HS-DPCCH transmission processing unit 23 operate as in mode 1 in FIG.

  That is, in mode 1, the control unit 17 of the mobile station 15 controls the CPICH receiving unit 20 to receive CPICH (pilot signal) at A1 in the figure and measure the reception quality of CPICH obtained by the reception.

  However, since CPICH reception is also required for HS-SCCH and HS-DSCH demodulation processing, reception is continued in the case of HS-SCCH and HS-DSCH reception.

  The control unit 17 obtains the result (for example, reception SIR), reads out the CQI information corresponding to the reception SIR based on the CQI table stored in the storage unit 19, and transmits it in B1 in the figure.

  Then, the mobile station 15 receives the HS-SCCH at C1 in the figure within a predetermined time (T1) from the transmission of B1, and receives the D1 when the transmission addressed to itself is announced.

  Thereafter, the control unit 17 performs control so that the HS-SCCH is transmitted from the radio base station 1 but is not received, and the HS-SCCH reception process is performed so that the next HS-SCCH is received at C2. The unit 21 is controlled.

  However, the control unit 17 similarly controls the HS-DPCCH transmission processing unit 23 to transmit the CQI information before a predetermined time (T1).

  That is, the control unit 17 controls the CPICH reception unit 20 to measure the CPICH reception quality in A2, similarly reads out the CQI information using the CQI table, and transmits the CQI information to the HS-DPCCH transmission processing unit 23.

  As described above, HS-SCCH reception is intermittently performed (the wireless base station 15 does not receive HS-SCCH during the period from C1 to C2), but predetermined for the intermittent reception. Since CQI information that affects the transmission format is intermittently transmitted (transmitted by B1 and B2) via the HS-DPCCH before time (T1), HS- transmitted by C1 (D1) and C2 (D2) The latest CQI information (radio environment information) can be reflected on the SCCH (HS-PDSCH).

  However, as T1, when the CQI information transmitted from the mobile station 15 is received by the radio base station 1 and data for transmission of HS-SCCH is generated, it is set within a time that can reflect the CQI information. desirable. This is because the control unit 3 of the radio base station 1 determines the transmission format of data to be transmitted via the HS-PDSSCH based on the received CQI, and transmits information regarding the transmission format via the HS-SCCH. Of course, when HS-SCCH is omitted, T1 may be set so that CQI information is transmitted in time for determination of the transmission format of HS-PDSCH.

  In addition, when the mobile station 15 is in mode 1, the control unit 3 of the radio base station 1 also sends the HS-SCCH to the mobile station 15 in a cycle shorter than the transmission cycle of the HS-SCCH received by C1 and C2. It is desirable to control the HS-SCCH transmission processing unit 7 so as not to transmit. This is to prevent the HS-SCCH from being transmitted at a timing that the mobile station 15 does not receive.

  However, between C1 and C2, HS-SCCH may be transmitted to other mobile stations in a short cycle.

  In this example, in mode 1, the mobile station 15 uses the same HS-SCCH reception cycle (first cycle) and CQI information transmission cycle (second cycle) via the HS-DPCCH.

  FIG. 6 is a diagram for explaining the transmission / reception cycle in detail.

  As shown in the figure, the first period, which is the HS-SCCH reception period, and the second period, which is the HS-DPCCH (CQI information) transmission period, are set to the same length.

  With such a period relationship, the latest CQI information can be used every time the HS-SCCH is transmitted while suppressing the frequency of transmission of the CQI information as much as possible.

  Of course, as shown in the figure, the CPICH reception cycle (third reception cycle) performed for generating the CQI information can also have the same length as the first cycle and the second cycle. This is to prevent unnecessary measurement even though CQI information is not transmitted.

  It is also possible to lengthen the second period with respect to the first period.

  FIG. 7 is a diagram for explaining the transmission / reception cycle in this case in detail.

  In this example, the mobile station 15 makes the CQI information transmission cycle (second cycle) via the HS-DPCCH longer than the HS-SCCH reception cycle (first cycle).

  In general, the power required for transmission is large with respect to reception, and the radio environment may not change much. Therefore, it is advisable to make the second period relatively long in order to reduce power consumption.

  5, 6, and 7, the CPICH reception cycle (third reception cycle) and CQI information transmission cycle (second cycle) performed for generating CQI information are the same. The third period can be shortened with respect to the two periods.

  FIG. 8 is a diagram for explaining the transmission / reception cycle in this case in detail.

  In this example, the control unit 17 of the mobile station 15 intermittently receives the HS-SCCH at the first cycle and intermittently transmits the CQI information at the second cycle that is the same cycle as the first cycle. The wireless transmission / reception unit 16 is controlled as described above. However, at that time, the control unit 17 controls the CPICH reception cycle (third cycle) to be shorter than the second cycle.

  That is, the CQI information is transmitted in the second period before the predetermined time (T1) from the reception of the HS-SCCH, and the CPICH is received a plurality of times during the period.

  Preferably, the control unit 17 averages the CPICH measurement results (reception SIR, etc.) received a plurality of times (see X in the figure), and refers to the CQI table in the storage unit 19 based on the averaged result. Then, the HS-DPCCH transmission processing unit 23 is controlled so that the CQI information is specified and transmitted via the HS-DPCCH.

  Thereby, the observation accuracy of the reception environment in the mobile station 15 is improved, and adaptive modulation control can be made more suitable for the actual radio environment.

  Now, returning to FIG. 5, the mode 2 will be described.

  As described above, in mode 1, CPICH, HS-SCCH, etc. are intermittently received, but in mode 2, CPICH, HS-SCCH, etc. are received more frequently (with a shorter period). Do. For example, each subframe of HS-SCCH is received (received intermittently).

  When there is a lot of data to be transmitted to the mobile station 15, the HS-PDSCH is assigned to the mobile station 15 more frequently, so the mobile station 15 needs to reduce the number of receptions by intermittent reception. small. Therefore, in this case, the HS-SCCH is received every time (every subframe) in accordance with each transmission timing of the HS-SCCH, and the CQI information is also frequently transmitted in accordance with the HS-SCCH. Here, the CQI information may be transmitted intermittently, but should not be transmitted more frequently than in mode 1.

  The mode control function unit 26 of the mobile station 15 changes the setting to the mode 1 and the mode 2.

  As described above, by having the function of switching between modes 1 and 2, the mobile station 15 can select an appropriate mode according to the situation, and the processing load may be in accordance with the data reception situation. it can.

  For example, when the period during which data is not transmitted to the local station via the HS-PDSCH exceeds a predetermined time, it can be considered that switching to mode 1 is more efficient, so the control unit detects this. Thus, switching from mode 2 to mode 1 is performed. It is desirable to set the mode 2 because the data reception status is unknown at the beginning when the HSDPA service is received.

  Mode 1 is characterized in that it has a longer HS-SCCH reception cycle and CQI transmission cycle than mode 2, but it can also be characterized by a CPICH reception cycle.

  This will be described with reference to FIG.

  FIG. 9 is a diagram for explaining the transmission / reception cycle in detail.

  As shown in the figure, in mode 2, although the CPICH reception period is longer than that in mode 1, the time width for reception is increased.

  At this time, it is desirable to increase the time width within a range in which the total CPICH reception time is shorter than that in mode 1.

  As a result, the mobile station 15 generates CQI information using the CPICH reception quality measured over a relatively long time immediately before transmitting the CQI information while reducing the reception load. It is because it can transmit to.

  Next, mode 3 will be described with reference to FIG.

  FIG. 10 is a diagram for explaining modes related to the present embodiment.

  As described above, the mode control function unit 26 can switch between the modes 1 and 2, but can further switch to the mode 3.

  This mode 3 corresponds to that in which transmission of CQI information is stopped in mode 1 (selection and reception of CPICH for generation of CQI information may be stopped selectively).

  That is, the mode control function unit 26 is initially set to mode 2, and when a time during which no data transmission from the wireless transmission / reception unit 16 to the local station is performed via the HS-PDSCH has passed a predetermined time (T2), Change the setting to 1. Further, after the setting is changed, the setting is changed to mode 3 when a predetermined time (T2) elapses when the data transmission from the wireless transmission / reception unit 16 to the own station via the HS-PDSCH is not performed. However, when data transmission addressed to the local station is performed via HS-PDSCH after the setting change to mode 1 and before T2 elapses, it is desirable to set to return to mode 2.

  In mode 3, when data transmission addressed to the own station via HS-PDSCH is performed, the mode can be returned to either mode 1 or mode 2.

  As a result, the processing load can be reduced step by step according to the reception status of data via the shared channel.

  In this example, the mobile station 15 autonomously switches the mode, but it is also desirable for the radio base station 1 to grasp the change in the mode. Therefore, preferably, the control unit 17 of the mobile station 15 controls the radio transmission / reception unit 16 to transmit a signal for notifying its own mode (notifying mode change), and the mode determination unit of the radio base station 1 11 determines the mode of the mobile station 15 from the signal, and the HS-SC addressed to the mobile station 15 is within the range of the HS-SCCH reception period corresponding to the mode (N times the reception period (N is a natural number)). SCCH transmission and HS-PDSCH transmission are performed. Of course, the control unit 3 controls the HSDPCCH reception processing unit so as to acquire CQI information at a cycle corresponding to the mode.

  Conversely, the mode switching of the mobile station 15 can be performed under the initiative of the radio base station 1. The radio base station 1 obtains the amount of data to be transmitted to the mobile station 15 via the HS-PDSCH based on the storage information in the storage unit 5, and the data addressed to the mobile station 15 is determined by the first interface unit 4. Therefore, the mode determination unit 11 determines the mode of the mobile station 15 according to the monitoring result, and notifies the mobile station 15 of the determined mode by the notification processing unit 12 (for example, , A notification signal can be transmitted from the wireless transmission / reception unit 2 via the HS-SCCH).

  As a condition for mode switching, when data to be transmitted to the mobile station 15 is not held, it is determined as mode 3, and there is data to be transmitted, but the data amount is within a predetermined range, If the transmission priority of the mobile station 15 is lower than a predetermined priority, it can be considered that the mode 1 is determined, and in other cases, the mode 2 is determined.

  The mobile station 15 may give the mode notified by the notification processing unit 12 to the mode control function unit 26, and the mode control function unit 26 may set the notified mode in the mobile station 15.

  Finally, another method for thinning out transmission of CQI information will be described with reference to FIG.

  This method can be applied when it is desired to further reduce the transmission of CQI in both modes 1 and 2.

  That is, in this method, when the reception SIR does not change so much and as a result the CQI information does not change so much, the control unit 17 controls the transmission so as not to be transmitted even if it corresponds to the transmission cycle.

  For example, when the CQI information is the same as the previous time, the control unit 17 performs control so that transmission is not performed, or if the change is within a predetermined range (for example, CQI changes 1 or 2), It is controlled not to transmit.

  It should be noted that it is desirable that the modulation schemes such as QPSK and 16QAM do not change as long as they are regarded as substantially the same. This is because the amount of data that can be transmitted changes greatly, and if it is regarded as the same, the data transmission efficiency is greatly affected.

DESCRIPTION OF SYMBOLS 1 Radio base station 2 Wireless transmission / reception part 3 Control part 4 1st interface part 5 Storage part 6 CPICH transmission part 7 HS-SCCH transmission process part 8 HS-PDSCH transmission process part 9 HS-DPCCH reception process part 10 MAC-hs processing function Unit 11 mode determination unit 12 notification processing unit 15 mobile station 16 wireless transmission / reception unit 17 control unit 18 input / output unit 19 storage unit 20 CPICH reception unit 21 HS-SCCH reception processing unit 22 HS-PDSCH reception processing unit 23 HS-DPCCH transmission processing Unit 24 MAC-hs processing function unit 25 RLC layer processing function unit 26 mode control function unit

Claims (4)

A wireless communication system having a transmitting station and a receiving station,
The receiving station is
A reception unit that receives data via a shared channel and intermittently receives information indicating a change in the transmission format of the shared channel;
A transmission unit that intermittently transmits reception quality information that affects the transmission format of the data at a timing set to be a predetermined time before the timing of intermittent reception performed by the reception unit;
A wireless communication system comprising: The transmitting station is
In addition to transmitting data via the shared channel, the receiving station intermittently receives information indicating a change in the transmission format of the shared channel with respect to a receiving station that can be a destination of the data. A control signal for instructing intermittent transmission of reception quality information that affects the transmission format of the data at a timing set to be a predetermined time before the timing of intermittent reception performed by the reception unit A transmitter to transmit,
Radio communications system of claim 1 comprising the. The first cycle of intermittent reception performed by the receiving unit of the receiving station is the same as the second cycle of intermittent transmission performed by the transmitting unit of the receiving station, or the second cycle is set to be longer than the first cycle. Lengthened,
The radio communication system according to claim 1 or 2. The predetermined time is set reflecting the time at which the reception quality information that affects the transmission format of the data transmitted from the receiving station is received by the transmitting station.
The wireless communication system according to any one of claims 1 to 3.

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