JP2004104461A - Communication control method in mobile communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a communication control method and a communication controller, which assigns channels to a plurality of mobile stations without deteriorating a transmission quality characteristic in an up link of a mobile communication system of a CDMA-TDD system. <P>SOLUTION: The communication control method is in the mobile communication system (100) comprising a base station (111) and a plurality of the mobile stations (13n). The method is composed of a stage for measuring respective timings when up signals from a plurality of the mobile stations reach the base station (140) or obtaining position information of the respective mobile stations, a stage (141) for classifying a plurality of the mobile stations into the prescribed number of groups based on the respective timings or position information and a stage for assigning the channels for up link to the respective mobile stations in accordance with the group. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention generally relates to a communication control method in a mobile communication system, and a mobile communication system, a base station, and a control station. More particularly, the present invention relates to a communication control for allocating an uplink channel to a base station to a plurality of mobile stations in a CDMA-TDD mobile communication system. About the method.
[0002]
[Prior art]
For example, in a CDMA-TDD mobile communication system, how to allocate channels to uplinks from a plurality of mobile stations to a base station is important in system design. Hereinafter, a general method of allocating channels to a plurality of mobile stations in a CDMA-TDD mobile communication system will be described. First, in the CDMA-TDD system, as shown in FIG. 1, one frame (10 ms) is divided into 15 slots on a time axis (horizontal axis), and an uplink channel / downlink channel is assigned to each slot. Then, in each slot, the communication channel is code-multiplexed using the spreading code. That is, when channels are allocated to a plurality of mobile stations, channels are allocated to each mobile station using time 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 scheme will be described in detail with reference to FIG. In FIG. 1, communication channels are allocated 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 two slots are used to accommodate four mobile stations in the uplink channel, the mobile station 001 and the mobile station 002 are code-multiplexed in TS # 3, and the mobile station 003 and the mobile station are used in TS # 4. 004 is code-multiplexed.
[0004]
In a case where a plurality of mobile stations are code-multiplexed in the uplink, a process called timing advance (Timing Advance) is performed to match the timing at which the uplink signals of the respective mobile stations reach the radio base station. Timing advance refers to a mobile station in which the base station measures the timing of an uplink signal transmitted from the mobile station, and based on the measurement result, the timing at which the mobile station signal reaches the base station is code-multiplexed. The transmission timing is instructed to the mobile station so that the stations match each other, and the mobile station transmits an 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 four chips, it is not possible to correct a timing deviation smaller than four chips such as one chip and two chips.
[0005]
[Patent Document 1]
JP-A-2000-341746.
[0006]
[Problems to be solved by the invention]
However, when a plurality of mobile stations are code-multiplexed in the uplink of the CDMA-TDD scheme, when the timings at which the signals from the respective mobile stations reach the radio base station do not match, only a single mobile station is used. It is known that the transmission quality characteristics deteriorate in comparison.
[0007]
FIG. 2 shows that in the uplink in one time slot, i. If a single mobile station transmits, ii. When transmitting from a plurality of mobile stations and the signals from the plurality of mobile stations reach the radio base station at the same timing, iii. FIG. 9 shows simulation results for three cases in which a signal is transmitted by a plurality of mobile stations and the signals from the plurality of mobile stations reach the radio base station at different timings. The horizontal axis shows the bit energy / noise energy, and the vertical axis shows the bit error rate. According to this, i. → ii. → iii. In the order of iii. It can be seen that the characteristics are significantly deteriorated in the case of.
[0008]
Conventionally, in order to match the timing at which signals from a plurality of users reach the radio base station, a timing advance (Timing Advance) for controlling the transmission timing from each user is performed, but the control step unit is as large as 4 chips. It is not possible to cope with finer timing deviation compensation.
[0009]
Therefore, the present invention has been made in view of the above points, and a communication control method and communication method for allocating channels to a plurality of mobile stations without deteriorating transmission quality characteristics in an uplink of a CDMA-TDD mobile communication system. It is an object to provide a control device.
[Means for Solving the Problems]
A communication control method in a mobile communication system including a base station and a plurality of mobile stations according to one feature of the present invention for achieving the above object, wherein each uplink signal from the plurality of mobile stations reaches the base station Measuring the timing of each mobile station; classifying a plurality of mobile stations into a predetermined number of groups based on each timing; and 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, comprising the steps of: acquiring position information of each of the plurality of mobile stations; Classifying the mobile stations into a predetermined number of groups; and allocating an uplink channel to each mobile station according to the group.
[0011]
According to another aspect of the present invention, there is provided a communication control method for performing HSDPA 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. Measuring the timing; classifying the plurality of mobile stations into a predetermined number of groups based on each timing; and determining the time of transmitting the HS-SICH of each mobile station according to the group. Is done.
[0012]
According to another aspect of the present invention, there is provided a communication control method for performing HSDPA in a mobile communication system including a base station and a plurality of mobile stations, comprising the steps of: obtaining respective position information of a plurality of mobile stations; Categorizing the plurality of mobile stations into a predetermined number of groups based on the grouping; and determining a time to transmit the HS-SICH of each mobile station according to the group.
[0013]
According to another feature 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. The timing at which each uplink signal from a plurality of mobile stations reaches the base station is measured, and based on each timing, the plurality of mobile stations are classified into a predetermined number of groups. A mobile communication system characterized by allocating an uplink channel.
[0014]
According to another feature 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 the plurality of mobile stations reaches the base station, classifies the plurality of mobile stations into a predetermined number of groups based on each timing, and sets each mobile station according to the group. Is assigned to an uplink channel.
[0015]
According to another feature of the present invention, a base station in a mobile communication system performs wireless communication with a plurality of mobile stations; means for measuring 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 group.
[0016]
According to another feature of the present invention, a control station in a mobile communication system performs wireless communication with a plurality of mobile stations; means for measuring timing when each uplink signal from the plurality of mobile stations reaches a 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 group.
[0017]
According to another feature 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. Acquiring position information of each of the plurality of mobile stations, classifying the plurality of mobile stations into a predetermined number of groups based on each position information, and allocating an uplink channel to each mobile station according to the group; It is characterized by.
[0018]
According to another feature 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 obtains each position information of the plurality of mobile stations, classifies the plurality of mobile stations into a predetermined number of groups based on each position information, and sets a channel for uplink to each mobile station according to the group. Assigning;
[0019]
According to another feature of the present invention, a base station in a mobile communication system includes: a unit that performs wireless communication with a plurality of mobile stations; a unit that obtains position information of each of 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 group.
[0020]
According to another feature of the present invention, a control station in a mobile communication system includes: a unit that performs wireless communication with a plurality of mobile stations; a unit that obtains position information from 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 group.
[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, mobile stations having the same timing at which an uplink signal reaches a radio base station are code-multiplexed with each other, so that time is Since there is no chip shift in the uplink signal of the mobile station multiplexed in the slot, it is possible to prevent degradation of uplink transmission quality characteristics.
BEST MODE FOR CARRYING OUT 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 of 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 a cell 120 of the control station 110 and communicate with the control station 110. Be composed. The control station 110 communicates with the mobile stations 130, 131, 132,..., 13n using the IMT-2000 CDMA-TDD scheme (hereinafter, simply referred to as “TDD scheme”).
[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. 4A, or may be controlled only by the radio base station 111 as shown in FIG. It may be controlled, or may be 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 uplink channels 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 at which the respective uplink signals of the mobile stations 130, 131, 132,... 13n that are in the cell 120 and communicating with the control station 110 reach the radio base station ( Step 140). Next, the control station 110 divides the mobile stations 130, 131, 132,... 13n into a predetermined number of groups based on the timing at which the respective 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. The control station 110 communicates with nine mobile stations, that is, mobile stations 130, 131, 132,... 138. Then, as shown in FIG. 6, the control station 110 uses slots # 3, # 4, # 5, and # 5 as uplink slots to be allocated as uplink channels to the mobile stations 130, 131, 132,. Suppose that four slots # 6 are used. In addition, it is assumed that the mobile communication system 100 according to the present embodiment is executing a timing advance (Timing Advance). Therefore, the deviation of the timing at which the uplink signal of the mobile station reaches the radio base station from 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 timing of the uplink signal 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, the timing advance (Timing Advance) is controlled so as to be later than the absolute timing of the control station 110. For example, when the timing of the uplink signal of a certain mobile station is earlier than the absolute timing of the control station 110 by one chip, the timing advance (Timing Advance) is performed so that the timing is controlled to be three chips later than the absolute timing of the control station 110.
[0025]
The control station 110 measures the timing at which the respective uplink signals of the mobile stations 130, 131, 132,... 138 reach the radio base station in Step 140. According to the measurements, the mobile station 130 has a 0-chip delay, the mobile station 131 has a 1-chip delay, the mobile station 132 has a 2-chip delay, the mobile station 133 has a 0-chip delay, the mobile station 133 has a 2-chip delay, and the mobile station 134 has a 2-chip delay with respect to the absolute timing of the control station 110. Suppose that the result obtained is 2 chip delay, the mobile station 136 obtains 3 chip delay, the mobile station 137 obtains 2 chip delay, and the mobile station 138 obtains 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 into a groove 150 (not shown) as a 0-chip delay group, the mobile stations 131 and 138 are classified into a group 151 as a 1-chip delay group, and the mobile stations 132 and 134 are classified as a 2-chip delay group. 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 allocates # 3 as an uplink slot to the mobile stations 130 and 133 belonging to the 0-chip delay group 150 and uplinks to the mobile stations 131 and 138 belonging to the 1-chip delay group 151. # 4 is assigned as a slot for link, and # 5 is assigned as a slot for uplink to mobile stations 132, 134, 135, and 137 belonging to group 152 with two chip delays, and mobile station 136 belongs to group 153 with three chip delays. Is assigned as # 6 as an uplink slot. With the above control, in the uplink, since the uplink signal of each mobile station is code-multiplexed with the signal of the mobile station having the same timing, it is possible to prevent degradation of the uplink transmission quality characteristics.
[0027]
Further, 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 into a group 150 as a 0-chip delay group, classifies the mobile station 131 into a group 151 as a 1-chip delay group, and moves as a 2-chip delay group. Assume that stations 132, 134, 135, and 137 have been classified into group 152, and mobile station 136 has been classified into group 153 as a 3-chip delay group. When there are only three slots for uplink, for example, # 3, # 4, and # 5, the mobile stations 132, 134, 135, and 137 of the largest group 152 including four mobile stations On the other hand, slot # 3 is preferentially allocated. Next, the slot # 4 is assigned with next priority to the mobile stations 130, 133, and 138 belonging to the group 150 having the largest number of mobile stations. Further, the mobile station 131 of the group 151 and the mobile station 136 of the group 153 are allocated to the remaining slot # 5. According to the above control, in the uplink, the probability that the uplink signal of each mobile station is code-multiplexed with the signal of the mobile station having the same timing is increased, and deterioration of the uplink transmission quality characteristic can be prevented. Further, when the number of slots for uplink is smaller than the number of groups to be classified, as a selection method of selecting a group to which a slot is to be preferentially assigned, the number of mobile stations in the group is selected as described above. Not only that, but also the service type may be selected. That is, there is a selection method of preferentially allocating a slot that can be used alone to a group including mobile stations for packet data service or to a group including many mobile stations for packet data service. A selection method of preferentially allocating slots to a group including a mobile station of voice service or a group including many mobile stations of the voice service, or including a mobile station of high-speed packet service such as 384 kbps, or A selection method of preferentially allocating slots to a groove or the like including many mobile stations of a high-speed bucket service such as 384 kbps may be used.
[0028]
In the above example, in Step 141, the unit of grouping is 1 chip, but it may be classified into smaller units, for example, 1/4 chip unit, 1/3 chip unit, 1/2 chip unit.
[0029]
FIG. 7 shows a sequence of operation of typical mobile station 130, base station 111, and control station 110. The mobile station 130 performs wireless communication with the base station 111. The mobile station 130 transmits an uplink signal to the base station 111. The control station 110 measures the timing at which this uplink signal reaches the base station 111. The control station 110 also measures the arrival timing of uplink signals from other mobile stations 131-13n. 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
Second Embodiment A second embodiment according to the present invention will be described with reference to FIGS. In the present 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, which is an uplink common control channel thereof, will be briefly described. HSDPA is a technology for performing higher-speed packet transmission using various technologies such as AMC and HARQ. As a feature of channel assignment in HSDPA, there is a feature that one physical channel is time-shared by a plurality of mobile stations and shared. Hereinafter, a channel allocation method including a common control channel for uplink and downlink 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 of requesting communication, and determines the mobile station to which the HS-DSCH is to be allocated. As signaling information for demodulating the HS-DSCH, an HS-SCCH, which is a downlink common control channel, is transmitted to the mobile station, and after a predetermined time interval has elapsed, the HS-DSCH is transmitted.
[0031]
On the other hand, the mobile station that has received the HS-SCCH acquires the signaling information of the HS-DSCH assigned to itself, and receives the HS-DSCH transmitted after a predetermined time interval has elapsed. Then, after a predetermined time interval has elapsed since the reception of the HS-DSCH, the mobile station transmits uplink signaling information, that is, information on the state of the radio communication channel and whether the HS-DSCH has been successfully received ( ACK / NACK) and the like are transmitted on the HS-SICH, which is an uplink common control channel. In HSDPA using the TDD scheme, a TTI is one frame (15 slots). In general, the number of slots used for the HS-SICH is as small as at most one or two slots. Therefore, when transmitting the HS-DSCH to a plurality of mobile stations in one TTI, the HS for the plurality of mobile stations is required. -SICH is code-multiplexed. In addition, a time interval from when the HS-DSCH is received to when the HS-SICH is transmitted 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, in the mobile communication system 100 in which HSDPA is performed using the TDD scheme, attention is paid to consecutive frames #n, # n + 1, # n + 2, and # n + 3. In each frame, there is only one slot for transmitting the HS-SICH. In the present embodiment, HS-DSCH # 1, # 2, and # 3 are allocated to mobile stations 001, 002, and 003, respectively, in frame #n. In frame # n + 1, HS-DSCH # 4, # 5, and # 6 are assigned to mobile stations 001, 004, and 005, respectively. Then, the mobile station to which the HS-DSCH is assigned transmits the 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, the HS-SICH associated with the HS-DSCH of frame #n is transmitted in frame # n + 2 using a fixed time interval, and the HS-SICH associated with the HS-DSCH of frame # n + 1 is transmitted. The SICH is transmitted in frame # n + 3.
[0033]
A control method for 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. The configuration of the control station 110 according to the second embodiment of the present invention is also substantially the same as that of the first embodiment, and as shown in FIG. 4, a radio base station 111 that provides communication using the TDD scheme and 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. 4A, or only the radio base station 111 as shown in FIG. May be controlled by the wireless control station 112 as shown in FIG. 4C.
[0034]
The control station 110 according to the second embodiment is an uplink common control channel for the mobile stations 130, 131, 132,..., 13n that are in the cell 120 and perform HSDPA communication with the control station 110. The operation of assigning is 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 respective uplink signals of the mobile stations 130, 131, 132,..., 13n that are located in the cell 120 and performing HSDPA communication with the control station 110 reach the radio base station. The measurement is performed (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 at which each uplink signal reaches 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 assigned based on the classified group, and notifies each mobile station of the time interval (Step 242). Then, each mobile station to which the HS-DSCH is assigned transmits the HS-SICH to the radio base station based on the determined time interval between the HS-DSCH and the HS-SICH. The operation of the control station 110 will be described in more detail using a specific example. As shown in FIG. 10, in the mobile communication system 100 in which HSDPA is performed using the TDD scheme, attention is paid to consecutive frames #n, # n + 1, # n + 2, and # n + 3. Then, there are three HS-DSCHs in each of frame #n and frame # n + 1, and for each mobile station to which the HS-DSCH is assigned, the uplink signaling information related to the HS-DSCH is transmitted in frame # n + 2. Transmission is performed using HS-SICH slots, each of which has one slot at # n + 3. Now, as shown in the figure, the mobile station 130 is on HS-DSCH # 1, the mobile station 131 is on HS-DSCH # 2, the mobile station 132 is on HS-DSCH # 3, and the mobile station 133 is on HS-DSCH # 4. , HS-DSCH # 5 and mobile station 135 are assigned to HS-DSCH # 6. On the other hand, the timing at which the uplink signal of each mobile station measured at Step 240 reaches the radio base station is based on the absolute timing at the control station 110, with the mobile station 130 having a 0-chip delay, the mobile station 131 having a 1-chip delay, and the mobile station 132 having a The 0-chip delay, the 1-chip delay of the mobile station 133, the 0-chip delay of the mobile station 134, the 0-chip delay of the mobile station 135, and the 0-chip delay of the mobile station 136. At this time, in Step 241, the control station 110 classifies the mobile stations 130, 132, 134, 135, and 136 into a group 150 (not shown) as a 0-chip delay group, and classifies the mobile stations 131 and 133 into a group 151 as a 1-chip delay group. Classify into. Then, in Step 242, the control station 110 transmits the HS-DSCH and the HS-DSCH to the mobile stations 130, 132, 134, and 135 belonging to the group 150 so that the respective HS-SICHs are transmitted in the frame # n + 2. -Set a time interval with the SICH and notify each of the mobile stations 130, 132, 134 and 135. On the other hand, for the mobile stations 131 and 133 belonging to the group 151, the time interval between each HS-DSCH and the HS-SICH is set so that each HS-SICH becomes the frame # n + 3, and the mobile station 131 and 133 are notified.
[0035]
Further, when the number of slots for transmitting the HS-SICH is smaller than the number of groups to be classified, a slot for transmitting the HS-SICH is preferentially allocated to a group including the largest number of mobile stations. Processing may be performed. For example, in Step 241 of the flowchart, the control station 110 classifies the mobile stations 130, 133, and 135 into a group 150 as a 0-chip delay group, classifies the mobile station 131 into a group 151 as a 1-chip delay group, and moves as a 2-chip delay group. It is assumed that the station 132 is classified into a group 152 and the mobile station 134 is classified into a group 153 as a 3-chip delay group. In this case, the time interval between the HS-DSCH and the HS-SICH is generally at most about 2 or 3 frames, so that the HS-DSCH and the HS-SICH are not code-multiplexed with mobile stations in different groups. -It is difficult to determine the time interval between SICH. Therefore, the mobile stations in group 150 having the largest number of mobile stations are controlled to transmit the HS-SICH in frame # n + 2, and the mobile stations in the remaining groups 151, 152, and 153 transmit the HS-SICH in frame # n + 3. To control.
[0036]
Further, in the above example, the unit of grouping is 1 chip in Step 241, but it may be classified into smaller units, for example, 1/4 chip unit or 1/3 chip unit. Further, in the present embodiment, the case where HSDPA is performed in IMT-2000 CDMA-TDD is considered, but the present embodiment can be applied to the case where HSDPA is performed in IMT-2000 CDMA-FDD or the like. Further, the present embodiment may be applied to a case where communication is performed using not only HSDPA but also a common channel other than HSDPA, for example, a DSCH.
[0037]
Example 3
In the first and second embodiments, the timing at which the signal of the mobile station reaches the radio base station is used as a method of classifying the mobile stations into groups. The position information of each mobile station may be used instead of the timing. That is, in Step 141 or Step 241, the mobile stations are classified into predetermined groups based on the position information, and the uplink channels of the mobile stations are allocated according to the groups, or the time interval between the HS-DSCH and the 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 the like, or may be information indicating that the mobile station exists in a certain cell or sector, or a wide range such as indoor or outdoor. And 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 timings at which the uplink signals of both mobile stations reach the radio base station are high. Therefore, by using this embodiment, the same effect as in the first and second embodiments is obtained. 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 the signals of a plurality of mobile stations code-multiplexed in the uplink reach the radio base station is transmitted. Are the same, and since there is no chip shift between them, it is possible to prevent degradation of the uplink transmission quality characteristics.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram showing an example of a conventional method for allocating channels to a plurality of mobile stations.
FIG. 2 is a graph showing BER characteristics when code-multiplexing uplink signals from a plurality of mobile stations.
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 the first and second embodiments of the present invention.
FIG. 5 is a flowchart illustrating an 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 the first embodiment 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 illustrating an 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 (16)

A communication control method in a mobile communication system including a base station and a plurality of mobile stations, comprising:
Measuring each timing when each uplink signal from the plurality of mobile stations reaches a base station;
Classifying the plurality of mobile stations into a predetermined number of groups based on each of the timings; and allocating an uplink channel to each of the mobile stations according to the groups;
Communication control method composed of: A communication control method in a mobile communication system including a base station and a plurality of mobile stations, comprising:
Obtaining position information of each of the plurality of mobile stations;
Classifying the plurality of mobile stations into a predetermined number of groups based on the position information; and allocating an uplink channel to each mobile station according to the group;
Communication control method composed of: A communication control method for performing HSDPA in a mobile communication system including a base station and a plurality of mobile stations, comprising:
Measuring each timing when each uplink signal from the plurality of mobile stations reaches a base station;
Classifying the plurality of mobile stations into a predetermined number of groups based on the respective timings; and determining a timing of transmitting the HS-SICH of each of the mobile stations according to the groups;
Communication control method composed of: A communication control method for performing HSDPA in a mobile communication system including a base station and a plurality of mobile stations, comprising:
Obtaining position information of each of the plurality of mobile stations;
Classifying the plurality of mobile stations into a predetermined number of groups based on the respective location information; and determining a time of transmitting the HS-SICH of each of the mobile stations according to the groups;
Communication control method composed 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. 4. The communication control method according to claim 1, wherein mobile stations having the same timing are classified into the same group. 5. The communication control method according to claim 2, wherein mobile stations located at substantially the same distance from the base station are classified into the same group. Mobile communication system:
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;
Consisting of
The base station measures the timing at which each uplink signal from the plurality of mobile stations reaches the base station, classifies the plurality of mobile stations into a predetermined number of groups based on each timing, and Allocating an uplink channel to each mobile station accordingly;
A mobile communication system, comprising: Mobile communication system:
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;
Consisting of
The control station measures a timing at which each uplink signal from the plurality of mobile stations reaches a base station, classifies the plurality of mobile stations into a predetermined number of groups based on each timing, and according to the group. Assigning an uplink channel to each of the mobile stations;
A mobile communication system, comprising: A base station in a mobile communication system, comprising:
Means for performing wireless communication with a plurality of mobile stations;
Means for measuring the timing at which each uplink signal from the plurality of mobile stations reaches the base station;
Means for classifying the plurality of mobile stations into a predetermined number of groups based on each of the timings;
Means for assigning an uplink channel to each mobile station according to the group;
A base station consisting of A control station in a mobile communication system, comprising:
Means for performing wireless communication with a plurality of mobile stations;
Means for measuring the timing at which each uplink signal from the plurality of mobile stations reaches a base station;
Means for classifying the plurality of mobile stations into a predetermined number of groups based on each of the timings;
Means for assigning an uplink channel to each mobile station according to the group;
Control station consisting of Mobile communication system:
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;
Consisting of
The base station obtains each location information of the plurality of mobile stations, classifies the plurality of mobile stations into a predetermined number of groups based on each location information, and goes up to each of the mobile stations according to the group. Assign a channel for the link;
A mobile communication system, comprising: Mobile communication system:
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;
Consisting of
The control station obtains each position information of the plurality of mobile stations, classifies the plurality of mobile stations into a predetermined number of groups based on each position information, and goes up to each of the mobile stations according to the group. Assign a channel for the link;
A mobile communication system, comprising: A base station in a mobile communication system, comprising:
Means for performing wireless communication with a plurality of mobile stations;
Means for acquiring position information of each of the plurality of mobile stations;
Means for classifying the plurality of mobile stations into a predetermined number of groups based on the position information;
Means for assigning an uplink channel to each mobile station according to the group;
A base station consisting of A control station in a mobile communication system, comprising:
Means for performing wireless communication with a plurality of mobile stations;
Means for obtaining location information from the plurality of mobile stations;
Means for classifying the plurality of mobile stations into a predetermined number of groups based on the position information;
Means for assigning an uplink channel to each mobile station according to the group;
Control station consisting of

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