JP3788963B2 - Communication control method in mobile communication system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
TECHNICAL FIELD The present invention generally relates to a communication control method and a mobile communication system, a base station, and a control station in a mobile communication system, and more particularly to a communication control for assigning uplink channels to a base station to a plurality of mobile stations in a CDMA-TDD mobile communication system. Regarding the method.
[0002]
[Prior art]
For example, in a CDMA-TDD mobile communication system, how to allocate a channel to uplinks from a plurality of mobile stations to a base station is important in system design. A general method for assigning channels to a plurality of mobile stations in a CDMA-TDD mobile communication system will be described below. First, in the CDMA-TDD system, as shown in FIG. 1, one frame (10 ms) is divided into 15 slots on the time axis (horizontal axis), and an uplink channel / downlink channel is assigned to each slot. In each slot, the communication channel is code-multiplexed using a spreading code. That is, when allocating channels to a plurality of mobile stations, channels are allocated to each mobile station using time-division multiplexing by slots and code multiplexing by codes in the same slot.
[0003]
An example of a general mobile station multiplexing method in the CDMA-TDD system will be described in detail with reference to FIG. In FIG. 1, communication channels are assigned to four mobile stations, that is, mobile station 001, mobile station 002, mobile station 003, and mobile station 004. The mobile station 001 is assigned TS # 3 as an uplink channel and TS # 5-7 as a downlink channel. The mobile station 002 is assigned TS # 3 as an uplink channel and TS # 8-11 as a downlink channel. The mobile station 003 is assigned TS # 4 as an uplink channel and TS # 12-13 as a downlink channel. The mobile station 004 is assigned TS # 4 as an uplink channel and TS # 14-15 as a downlink channel. In this case, since only 2 slots are used to accommodate 4 mobile stations in the uplink channel, mobile station 001 and mobile station 002 are code-multiplexed in TS # 3, and mobile station 003 and mobile station are transmitted in TS # 4. 004 is code-multiplexed.
[0004]
In the uplink, when a plurality of mobile stations are code-multiplexed, a process called timing advance is performed in order to match the timing at which the uplink signal of each mobile station reaches the radio base station. Timing advance is a movement in which the radio base station measures the timing of the uplink signal transmitted from the mobile station, and the timing at which the mobile station signal reaches the radio base station is code-multiplexed based on the measurement result. The transmission timing is instructed to the mobile station so that the stations match each other, and the mobile station transmits the uplink signal at the timing instructed by the radio base station. However, in the timing advance currently specified in 3GPP [3GPPTS25.224v5.0.0 (2002-3)], the minimum control unit is 4 chips. That is, since the transmission timing is controlled in units of 4 chips, timing deviation smaller than 4 chips such as 1 chip and 2 chips cannot be corrected.
[0005]
[Patent Document 1]
Japanese Patent Laid-Open No. 2000-341746.
[0006]
[Problems to be solved by the invention]
However, when multiple mobile stations are code-multiplexed in the uplink of the CDMA-TDD scheme, when the timing when the signals from the respective mobile stations reach the radio base station does not match, It is known that the transmission quality characteristic is deteriorated as compared with it.
[0007]
In FIG. 2, in the uplink in one time slot, i. When a single mobile station transmits, ii. Transmits from a plurality of mobile stations, and signals from the plurality of mobile stations are transmitted to the radio base station at the same timing. In the case of arrival, iii. Shows simulation results for three cases where transmission is performed by a plurality of mobile stations and signals from the plurality of mobile stations arrive at the radio base station at different timings. The horizontal axis represents the bit energy / noise energy, and the vertical axis represents the bit error rate. According to this, it can be seen that the characteristics deteriorate in the order of i. → ii. → iii. In particular, in the case of iii.
[0008]
Conventionally, timing advance (Timing Advance) for controlling the transmission timing from each user is performed in order to match the timing when signals from a plurality of users arrive at the radio base station, but the control step unit is as large as 4 chips, It cannot cope with finer timing deviation compensation.
[0009]
Accordingly, the present invention has been made in view of the above points, and in the uplink of a CDMA-TDD mobile communication system, a communication control method and communication for allocating channels to a plurality of mobile stations without degrading transmission quality characteristics An object is to provide a control device.
[Means for Solving the Problems]
According to one aspect of the present invention for achieving the above object, a communication control method in a mobile communication system including a base station and a plurality of mobile stations, wherein each uplink signal from the plurality of mobile stations reaches the base station. A step of measuring each timing; a step of classifying a plurality of mobile stations into a predetermined number of groups based on each timing; and a step of allocating an uplink channel to each mobile station according to the group; Is done.
[0010]
According to another aspect of the present invention, there is provided a communication control method in a mobile communication system including a base station and a plurality of mobile stations, obtaining each position information of the plurality of mobile stations; Categorizing the mobile stations into a predetermined number of groups; and allocating an uplink channel to each mobile station according to the groups.
[0011]
According to another aspect of the present invention, a communication control method when performing HSDPA in a mobile communication system including a base station and a plurality of mobile stations is provided for each uplink signal from a plurality of mobile stations reaching the base station. A step of measuring timing; a step of classifying a plurality of mobile stations into a predetermined number of groups based on each timing; and a step of determining when to transmit HS-SICH of each mobile station according to the group; Is done.
[0012]
According to another aspect of the present invention, a communication control method for performing HSDPA in a mobile communication system including a base station and a plurality of mobile stations is the step of acquiring each position information of the plurality of mobile stations; And a step of classifying a plurality of mobile stations into a predetermined number of groups; and a step of determining when to transmit the HS-SICH of each mobile station according to the group.
[0013]
According to another aspect of the present invention, a mobile communication system includes: a base station; and a plurality of mobile stations that perform radio communication with the base station and transmit uplink signals to the base station; Measure the timing at which each uplink signal from a plurality of mobile stations arrives at the base station, classify the plurality of mobile stations into a predetermined number of groups based on each timing, and assign each mobile station according to the group A mobile communication system characterized by assigning an uplink channel.
[0014]
According to another aspect of the present invention, a mobile communication system includes: a control station; a base station; and a plurality of mobile stations that perform radio communication with the base station and transmit uplink signals to the base station; The station measures the timing at which each uplink signal from a plurality of mobile stations arrives at the base station, and classifies the plurality of mobile stations into a predetermined number of groups based on each timing, and each mobile station according to the group An uplink channel is assigned to the;
[0015]
According to another aspect of the present invention, a base station in a mobile communication system comprises: means for performing wireless communication with a plurality of mobile stations; means for measuring a timing at which each uplink signal from a plurality of mobile stations reaches the base station Means for classifying a plurality of mobile stations into a predetermined number of groups based on each timing; means for allocating an uplink channel to each mobile station according to the groups;
[0016]
According to another aspect of the present invention, the control station in the mobile communication system comprises: means for performing wireless communication with a plurality of mobile stations; means for measuring timing at which each uplink signal from the plurality of mobile stations reaches the base station; Means for classifying a plurality of mobile stations into a predetermined number of groups based on each timing; means for allocating an uplink channel to each mobile station according to the groups;
[0017]
According to another aspect of the present invention, a mobile communication system includes: a base station; and a plurality of mobile stations that perform radio communication with the base station and transmit uplink signals to the base station; Obtaining location information of a plurality of mobile stations, classifying the plurality of mobile stations into a predetermined number of groups based on the location information, and allocating uplink channels to the mobile stations according to the groups; It is characterized by.
[0018]
According to another aspect of the present invention, a mobile communication system includes: a control station; a base station; and a plurality of mobile stations that perform radio communication with the base station and transmit uplink signals to the base station; The station acquires each position information of the plurality of mobile stations, classifies the plurality of mobile stations into a predetermined number of groups based on the position information, and sets an uplink channel to each mobile station according to the group. It is characterized by assigning.
[0019]
According to another aspect of the present invention, a base station in a mobile communication system comprises: means for performing wireless communication with a plurality of mobile stations; means for acquiring position information of a plurality of mobile stations; Means for classifying the mobile stations into a predetermined number of groups; means for allocating an uplink channel to each mobile station according to the groups;
[0020]
According to another aspect of the present invention, a control station in a mobile communication system includes: means for performing wireless communication with a plurality of mobile stations; means for acquiring position information from the plurality of mobile stations; Means for classifying the mobile stations into a predetermined number of groups; means for allocating an uplink channel to each mobile station according to the groups;
[Action]
According to the communication control method according to one aspect of the present invention, when channels are allocated to a plurality of mobile stations in the uplink, the mobile stations having the same timing when the uplink signal reaches the radio base station are code-multiplexed. Since there is no chip shift in the uplink signal of the mobile station multiplexed in the slot, it is possible to prevent deterioration in uplink transmission quality characteristics.
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0021]
Example 1
Embodiment 1 according to the present invention will be described with reference to FIG. FIG. 3 is a schematic configuration diagram of the mobile communication system 100 according to the present embodiment. The mobile communication system 100 of the present embodiment includes a control station 110 and a plurality of mobile stations 130, 131, 132,... 13n that are located in the cell 120 of the control station 110 and communicate with the control station 110. Composed. The control station 110 communicates with the mobile stations 130, 131, 132,... 13n using the IMT-2000 CDMA-TDD system (hereinafter simply referred to as “TDD system”).
[0022]
As shown in FIG. 4A, the control station 110 includes a plurality of radio base stations 111 that provide communication using the TDD scheme, and a radio control station 112 that controls them. The communication control method according to the present invention may be controlled by both the radio base station 111 and the radio control station 112 as shown in FIG. 4 (a), or only by the radio base station 111 as shown in FIG. 4 (b). It may be controlled, and may be further controlled only by the radio control station 112 as shown in FIG. An operation in which the control station 110 according to the first embodiment allocates an uplink channel to the mobile stations 130, 131, 132,... 13n that are located in the cell 120 and communicate with the control station 110 will be described below.
[0023]
FIG. 5 is a flowchart illustrating the operation of the control station 110 according to the first embodiment. First, the control station 110 measures the timing when each uplink signal of the mobile stations 130, 131, 132,... 13n located in the cell 120 and communicating with the control station 110 reaches the radio base station ( Step140). Next, the control station 110 assigns the mobile stations 130, 131, 132,... 13n to a predetermined number of groups based on the timing at which the uplink signals of the mobile stations 130, 131, 132,. (Step 141). Then, the control station 110 allocates an uplink slot to each mobile station based on the classified group (Step 142).
[0024]
The operation of the control station 110 will be described in more detail using a specific example with reference to FIG. Consider a case where the control station 110 communicates with nine mobile stations, that is, mobile stations 130, 131, 132,. Then, as shown in FIG. 6, the control station 110 uses the slots # 3, # 4, # 5, as slots for uplink to be assigned to the mobile stations 130, 131, 132,. Suppose you use 4 slots of # 6. In addition, it is assumed that the mobile communication system 100 according to the present embodiment is executing timing advance. Therefore, the deviation of the timing at which the uplink signal of the mobile station reaches the radio base station with respect to the absolute timing at the control station 110 is considered to be within 3 chips. Further, in this embodiment, in order to reduce the number of groups to be classified, it is assumed that the uplink signal timing of the mobile station is always delayed with respect to the absolute timing of the control station 110. That is, when the timing of the uplink signal of the mobile station is earlier than the absolute timing of the control station 110, control is performed so as to be delayed with respect to the absolute timing of the control station 110 by timing advance. For example, when the timing of an uplink signal of a certain mobile station is one chip earlier than the absolute timing of the control station 110, control is performed so as to be 3 chips later than the absolute timing of the control station 110 by timing advance.
[0025]
In Step 140, the control station 110 measures the timing at which the uplink signals of the mobile stations 130, 131, 132, ... 138 arrive at the radio base station. According to the measurement, the mobile station 130 is 0-chip delay, the mobile station 131 is 1-chip delay, the mobile station 132 is 2-chip delay, the mobile station 133 is 0-chip delay, the mobile station 134 is 2-chip delay, and the mobile station 135 is relative to the absolute timing of the control station 110. Suppose that the result is 2 chip delay, the mobile station 136 is 3 chip delay, the mobile station 137 is 2 chip delay, and the mobile station 138 is 1 chip delay.
[0026]
At this time, in Step 141, the control station 110 classifies each mobile station into a groove according to the number of delay chips. That is, the mobile stations 130 and 133 are classified as a groove 150 (not shown) as a 0-chip delay group, the mobile stations 131 and 138 are classified as a group 151 as a 1-chip delay group, and the mobile stations 132, 134, 135 and 137 are classified into a group 152, and the mobile station 136 is classified into a group 153 as a 3-chip delay group. Then, in Step 142, the control station 110 assigns # 3 as an uplink slot to the mobile stations 130 and 133 belonging to the 0 chip delay group 150 and the uplink to the mobile stations 131 and 138 belonging to the 1 chip delay group 151. # 4 is assigned as a slot for the link, # 5 is assigned as a slot for uplink to the mobile stations 132, 134, 135, and 137 belonging to the 2-chip delay group 152, and the mobile station 136 that belongs to the group 153 of 3-chip delay. # 6 is assigned as a slot for uplink. With the above control, in the uplink, the uplink signal of each mobile station is code-multiplexed with the signal of the mobile station having the same timing, so that it is possible to prevent deterioration in uplink transmission quality characteristics.
[0027]
In addition, when the number of uplink slots is smaller than the number of groups to be classified, a process of preferentially allocating slots to a group including the largest number of mobile stations may be performed. For example, in Step 141 of the flowchart, the control station 110 classifies the mobile stations 130, 133, and 138 as the 0 chip delay group into the group 150, classifies the mobile station 131 as the 1 chip delay group, and moves as the 2 chip delay group. Assume that stations 132, 134, 135, and 137 are classified into group 152, and mobile station 136 is classified into group 153 as a 3-chip delay group. When there are only 3 slots for uplink such as # 3, # 4, and # 5, the mobile station 132, 134, 135, 137 of the largest group 152 including 4 mobile stations is assigned. On the other hand, slot # 3 is preferentially assigned. Next, slot # 4 is assigned to the mobile stations 130, 133, and 138 belonging to the group 150 having the next largest number of mobile stations in the next priority. Furthermore, the mobile station 131 of the group 151 and the mobile station 136 of the group 153 are allocated to the remaining slot # 5. With the above control, in the uplink, the uplink signal of each mobile station has a high probability of being code-multiplexed with the signal of the mobile station having the same timing, and it is possible to prevent deterioration in uplink transmission quality characteristics. Further, when the number of uplink slots is smaller than the number of groups to be classified, as a selection method for selecting a group to which slots are preferentially selected, the number of mobile stations in the group as described above is selected. Not only the service type but also the service type may be selected. That is, there is a selection method in which a slot that can be used independently is preferentially assigned to a group that includes mobile stations that serve packet data or a group that includes many mobile stations that serve packet data. In addition, a selection method of preferentially allocating a slot to a group including a voice service mobile station or a group including a plurality of voice service mobile stations, or including a mobile station of a high-speed packet service such as 384 kbps, or A selection method in which slots are preferentially allocated to a groove or the like including many mobile stations for high-speed bucket service such as 384 kbps may be used.
[0028]
In the above example, in Step 141, the grouping unit is set to 1 chip. However, the unit may be classified into smaller units, for example, 1/4 chip unit, 1/3 chip unit, or 1/2 chip unit.
[0029]
FIG. 7 shows a sequence of operations of typical mobile station 130, base station 111, and control station 110. The mobile station 130 performs wireless communication with the base station 111. An uplink signal is transmitted from the mobile station 130 to the base station 111. The control station 110 measures the timing at which this uplink signal reaches the base station 111. The arrival timing of the uplink signal from the mobile station 131-13n as well as the control station 110 is also measured. According to each timing obtained by the measurement, the control station 110 classifies the mobile stations 130-13n into a predetermined number of groups. Next, the control station 110 allocates an uplink slot to the mobile station 130 based on the classified group. The mobile station 130 performs uplink communication with the base station 111 using the assigned slot.
[0030]
Example 2
Embodiment 2 according to the present invention will be described with reference to FIGS. In this embodiment, a case is considered in which the radio communication control method according to the present invention is applied to HS-SICH, which is an uplink common control channel when HSDPA is performed using the TDD scheme. First, an outline of HSDPA using the TDD scheme and HS-SICH that is an uplink common control channel will be briefly described. HSDPA is a technology that performs higher-speed packet transmission using various technologies such as AMC and HARQ. A feature of channel assignment in HSDPA is that one physical channel is time-shared by a plurality of mobile stations. Hereinafter, a channel assignment method including uplink and downlink common control channels in HSDPA will be described. First, the control station performs scheduling using information such as the status of the wireless communication channel of the mobile station performing HSDPA communication or the order in which communication is requested, and determines a mobile station to which the HS-DSCH is allocated. As signaling information for demodulating the HS-DSCH, HS-SCCH, which is a downlink common control channel, is transmitted to the mobile station, and after a predetermined time interval elapses, HS-DSCH is transmitted.
[0031]
On the other hand, the mobile station that has received HS-SCCH acquires HS-DSCH signaling information assigned to itself, and receives HS-DSCH that is transmitted after a predetermined time interval has elapsed. Then, after a predetermined time interval has elapsed since receiving the HS-DSCH, the mobile station transmits uplink signaling information, that is, information on the status of the radio communication channel and whether the HS-DSCH has been successfully received ( ACK / NACK) and the like are transmitted on HS-SICH, which is an uplink common control channel. In HSDPA using the TDD scheme, the TTI is one frame (15 slots). In general, since the number of slots used for HS-SICH is as small as 1 or 2 slots, when transmitting HS-DSCH to multiple mobile stations in 1 TTI, HS for multiple mobile stations is used. -SICH is code multiplexed. In addition, the time interval from the reception of HS-DSCH to the transmission of HS-SICH is generally determined by the control station.
[0032]
A specific example of a channel allocation method in general HSDPA will be described with reference to FIG. As shown in FIG. 8, attention is paid to consecutive frames #n, # n + 1, # n + 2, and # n + 3 in the mobile communication system 100 performed by HSDPA using the TDD scheme. In each frame, there is only one slot for transmitting HS-SICH. In this embodiment, HS-DSCH # 1, # 2, and # 3 are allocated to mobile stations 001, 002, and 003 in frame #n, respectively. In frame # n + 1, HS-DSCH # 4, # 5, and # 6 are allocated to mobile stations 001, 004, and 005, respectively. Then, the mobile station assigned the HS-DSCH transmits HS-SICH in frames # n + 2 and # n + 3. The time interval between HS-DSCH and HS-SICH is determined by the control station. In general, as shown in FIG. 8, using a fixed time interval, an HS-SICH related to the HS-DSCH of frame #n is transmitted in frame # n + 2, and the HS-DSCH of frame # n + 1 is transmitted. The associated HS-SICH is transmitted in frame # n + 3.
[0033]
A control method related to HS-SICH transmission when the present invention is applied in the second embodiment will be described. The configuration diagram of the mobile communication system of the second embodiment according to the present invention is essentially the same as the mobile communication system of the first embodiment, and is shown in FIG. Further, the configuration of the control station 110 of the second embodiment according to the present invention is essentially the same as that of the first embodiment, and the radio base station 111 that provides communication using the TDD scheme as shown in FIG. And a radio control station 112 that controls. The communication control method according to the present invention may be controlled by both the radio base station 111 and the radio control station 112 as shown in FIG. 4 (a), or only the radio base station 111 as shown in FIG. 4 (b). Or may be controlled only by the radio control station 112 as shown in FIG. 4 (c).
[0034]
HS-SICH which is an uplink common control channel for mobile stations 130, 131, 132,..., 13n in which the control station 110 according to the second embodiment is located in the cell 120 and performs HSDPA communication with the control station 110. The operation of assigning will be described. FIG. 9 is a flowchart illustrating the operation of the control station 110 according to the second embodiment. First, the control station 110 determines the timing at which the uplink signals of the mobile stations 130, 131, 132,..., 13n that are located in the cell 120 and perform HSDPA communication with the control station 110 reach the radio base station. Measure (Step 240). Next, the control station 110 classifies the mobile stations 130, 131, 132,..., 13n into a predetermined number of groups based on the timing of each uplink signal reaching the radio base station (Step 241). Then, the control station 110 determines a time interval between the HS-DSCH and the HS-SICH for each mobile station to which the HS-DSCH is allocated based on the classified group, and notifies each mobile station (Step 242). Then, each mobile station to which the HS-DSCH is assigned transmits HS-SICH to the radio base station based on the determined time interval between HS-DSCH and HS-SICH. The operation of the control station 110 will be described in more detail using a specific example. As shown in FIG. 10, attention is paid to consecutive frames #n, # n + 1, # n + 2, and # n + 3 in the mobile communication system 100 in which HSDPA is performed using the TDD scheme. Then, three HS-DSCHs exist in each of frame #n and frame # n + 1, and for each mobile station to which the HS-DSCH is assigned, uplink signaling information related to the HS-DSCH is transmitted as frame # Transmission is performed using slots for HS-SICH, each having one slot for each of n + 2 and # n + 3. As shown in the figure, the mobile station 130 is in HS-DSCH # 1, the mobile station 131 is in HS-DSCH # 2, the mobile station 132 is in HS-DSCH # 3, and the mobile station 133 is in HS-DSCH # 4. It is assumed that the mobile station 134 is allocated to HS-DSCH # 5 and the mobile station 135 is allocated to HS-DSCH # 6. On the other hand, the timing at which the uplink signal of each mobile station arrives at the radio base station measured in Step 240 is 0 chip delay for the mobile station 130, 1 chip delay for the mobile station 131, and the mobile station 132 for the absolute timing in the control station 110. The 0-chip delay, the mobile station 133 is a 1-chip delay, the mobile station 134 is a 0-chip delay, the mobile station 135 is a 0-chip delay, and the mobile station 136 is a 0-chip delay. At this time, in Step 241, the control station 110 classifies the mobile stations 130, 132, 134, 135, 136 as a 0-chip delay group into a group 150 (not shown), and groups the mobile stations 131, 133 as a group 151 as a 1-chip delay group. Classify into: In Step 242, the control station 110 transmits each HS-DSCH for the mobile stations 130, 132, 134, 135 belonging to the group 150 so that each HS-SICH is transmitted in frame # n + 2. And a time interval between the mobile station 130, 132, 134, and 135 are set. On the other hand, for the mobile stations 131 and 133 belonging to the group 151, the time interval between each HS-DSCH and HS-SICH is set so that each HS-SICH becomes frame # n + 3. Notification is made to each of the mobile stations 131 and 133.
[0035]
In addition, when the number of slots for transmitting HS-SICH is smaller than the number of groups to be classified, a slot for transmitting HS-SICH is preferentially allocated to the group including the largest number of mobile stations. Processing may be performed. For example, in Step 241 of the above flowchart, the control station 110 classifies the mobile stations 130, 133, and 135 as a 0-chip delay group into the group 150, classifies the mobile station 131 as the 1-chip delay group, and moves as a 2-chip delay group. Consider a case where station 132 is classified into group 152 and mobile station 134 is classified into group 153 as a 3-chip delay group. In this case, since the time interval between HS-DSCH and HS-SICH is generally about 2 frames or 3 frames at most, HS-DSCH and HS are set so as not to code-multiplex mobile stations of different groups. -It is difficult to determine the time interval with SICH. Therefore, control is performed so that the mobile stations in the group 150 having the largest number of mobile stations transmit HS-SICH in frame # n + 2, and the mobile stations in the remaining groups 151, 152, and 153 are in HS in frame # n + 3. -Control to send SICH.
[0036]
Further, in the above example, the grouping unit is set to 1 chip in Step 241, but the units may be classified into smaller units, for example, 1/4 chip units or 1/3 chip units. In this embodiment, the case of performing HSDPA in IMT-2000CDMA-TDD has been considered. However, the present embodiment can also be applied to the case of performing HSDPA in IMT-2000CDMA-FDD. Furthermore, this embodiment may be applied not only to HSDPA but also to communication using a common channel other than HSDPA, such as DSCH.
[0037]
Example 3
In the first and second embodiments described above, as a method for classifying mobile stations into groups, the timing at which the mobile station signals reach the radio base station is used. The location information of each mobile station may be used instead of the timing. That is, in Step 141 or Step 241, the mobile station is classified into a predetermined group based on the location information, and the uplink channel of the mobile station is assigned according to the group, or the time interval between HS-DSCH and HS-SICH is set. You may decide. Here, the position information of the mobile station may be coordinate position information displayed using, for example, GPS, or may be information that exists in a certain cell or sector, or may be indoor or outdoor. The position information may include position information in various meanings. When the positions of the two mobile stations are the same, there is a high probability that the timing at which the uplink signals of both mobile stations will reach the radio base station is high. It is considered that an effect can be obtained.
【The invention's effect】
As described above, according to the embodiment of the present invention, when communication is performed using the TDD scheme, each timing at which signals of a plurality of mobile stations that are code-multiplexed in the uplink arrive at a radio base station Since there is no mutual chip shift, it is possible to prevent deterioration of uplink transmission quality characteristics.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram showing an example of a method for assigning channels to a plurality of mobile stations according to the prior art.
FIG. 2 is a graph showing BER characteristics when uplink signals of a plurality of mobile stations are code-multiplexed.
FIG. 3 is a schematic configuration diagram of a mobile communication system 100 according to Embodiments 1 and 2 of the present invention.
FIG. 4 is a configuration diagram of a control station 110 and the like according to Embodiments 1 and 2 of the present invention.
FIG. 5 is a flowchart showing the operation of the control station 110 according to the first embodiment of the present invention.
FIG. 6 shows an example of a frame configuration in uplink channel allocation according to Embodiment 1 of the present invention.
FIG. 7 is a sequence chart showing operations of a mobile station, a base station, and a control station according to the first embodiment of the present invention.
FIG. 8 is a diagram illustrating an HS-SICH transmission method.
FIG. 9 is a flowchart showing the operation of the control station 110 according to the second embodiment of the present invention.
FIG. 10 is a diagram illustrating an example of an HS-SICH transmission method according to Embodiment 2 of the present invention.
[Explanation of symbols]
100 Mobile communication system
110 Control station
111 base station
112 Radio control station
120 cells
131-13n mobile station

Claims (14)

A communication control method in a mobile communication system including a base station and a plurality of mobile stations, comprising:
Measuring each timing at which each code-multiplexed uplink signal from the plurality of mobile stations arrives at a base station based on a chip ;
Based on the timing of measurement of the so mobile stations having the same timing are classified into the same group, the step classifying the plurality of mobile stations into groups of a predetermined number; to assign each and the groups Allocating an uplink channel to each mobile station;
A communication control method comprising: The communication control method according to claim 1, wherein each of the timings is set. chip The step of measuring based on chip A communication control method comprising the step of measuring timing in units of. A communication control method for performing HSDPA in a mobile communication system including a base station and a plurality of mobile stations:
Measuring each timing at which each code-multiplexed uplink signal from the plurality of mobile stations arrives at a base station based on a chip ;
On the basis of the respective timing, as mobile station having the same timing are classified into the same group, the plurality of mobile stations stages classified into a predetermined number of groups; to assign each and the groups, each Determining when to send the mobile station's HS-SICH;
A communication control method comprising: The communication control method according to claim 3, wherein each of the timings is set. chip The step of measuring based on chip A communication control method comprising the step of measuring timing in units of.   A control station capable of implementing the communication control method according to any one of claims 1 to 4.   A base station capable of implementing the communication control method according to any one of claims 1 to 4. A mobile communication system:
A base station; and a plurality of mobile stations that perform radio communication with the base station and transmit code-multiplexed uplink signals to the base station;
Consisting of
The base station measures the timing at which each uplink signal from the plurality of mobile stations arrives at the base station based on the chip, and based on each timing, mobile stations having similar timing are classified into the same group It said plurality of mobile stations classified into a predetermined number of groups so as to assign a channel for the uplink to each mobile station to allocate for each said group;
A mobile communication system. A mobile communication system:
Control station;
A base station; and a plurality of mobile stations that perform radio communication with the base station and transmit code-multiplexed uplink signals to the base station;
Consisting of
The control station measures the timing at which each uplink signal from the plurality of mobile stations arrives at the base station based on the chip, and based on each timing, mobile stations having similar timing are classified into the same group wherein the plurality of mobile stations classified into a predetermined number of groups, assigning a channel for the uplink to each mobile station to allocate for each said group;
A mobile communication system. A base station in a mobile communication system:
Means for wireless communication with a plurality of mobile stations;
Means for measuring , based on a chip , the timing at which each code-multiplexed uplink signal from the plurality of mobile stations arrives at the base station;
Means for classifying the plurality of mobile stations into a predetermined number of groups so that mobile stations having similar timings are classified into the same group based on the measured timings;
Means for allocating an uplink channel to each mobile station so as to be allocated for each group;
A base station consisting of A control station in a mobile communication system:
Means for wireless communication with a plurality of mobile stations;
Means for measuring the timing at which each code-multiplexed uplink signal from the plurality of mobile stations arrives at the base station based on a chip ;
Means for classifying the plurality of mobile stations into a predetermined number of groups so that mobile stations having similar timings are classified into the same group based on the measured timings;
Means for allocating an uplink channel to each mobile station so as to be allocated for each group;
A control station consisting of The mobile communication system according to claim 7, wherein chip Timing measurement based on chip A mobile communication system, characterized in that the timing measurement is performed in units. 9. A mobile communication system according to claim 8, wherein chip Timing measurement based on chip A mobile communication system, characterized in that the timing measurement is performed in units. A base station according to claim 9, wherein said base station chip Timing measurement based on chip A base station, characterized in that the timing is measured in units. The control station according to claim 10, wherein the control station chip Timing measurement based on chip A control station characterized in that it is a timing measurement in units.

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