JP3749249B2 - Mobile station, base station, communication system, and transmission control method - Google Patents

Description

  The present invention relates to a mobile communication system, a base station, a mobile station, and a transmission control method for performing wireless data communication at high speed.

As mobile radio communication systems represented by mobile phones, a plurality of communication systems called third generations have been adopted as IMT-2000 in the ITU (International Telecommunication Union), of which W-CDMA (Wideband Code Division Multiple Access). Regarding the system, commercial service was started in Japan in 2001.
The purpose of the W-CDMA system is to obtain a communication speed of about 2 Mbps (bit per second) at the maximum per mobile station. 3GPP (3rd Generation Partnership Project; ), The first standard specification has been determined and published as a release 99 (Release 1999) version, which is a version of the standard compiled in 1999. Note that Non-Patent Document 1 is available as a detailed explanation for the W-CDMA FDD system in general.

W-CDMA mobile communication system; supervised by Keiji Tachikawa; Maruzen Co., Ltd. 3GPP standard document TR25.858v1.1.2 (2002-02) “High Speed Downlink Packet Access: Physical Layer Aspects (Release 5)”

  FIG. 1 is a general conceptual diagram showing a conventional W-CDMA communication system. In FIG. 1, 1 is a base station (BS), and 2 is a mobile station that performs wireless communication with the base station 1. MS (Mobile Station), 3 is a downlink, 3a is individually assigned to mobile station 2 in downlink 3 used when base station 1 transmits data to mobile station 2 3b is a channel that is transmitted in common to a plurality of mobile stations 2 in the downlink 3 (a common channel), and 4 is when the mobile station 2 transmits data to the base station 1. It is the uplink (dedicated channel) used.

  As a W-CDMA system, a frequency division multiplexing (FDD) system that assigns downlink 3 and uplink 4 to different radio frequencies is separated from downlink 3 and uplink 4 in time using the same radio frequency. Although there is a time division multiplexing (TDD) method, the FDD method will be described here.

Next, the operation will be described.
The downlink 3a includes a DPDCH (Dedicated Physical Data Channel) that is a data channel and a DPCCH (Dedicated Physical Control Channel) that is a control channel, and both channels are time-multiplexed and transmitted.
The downlink 3 b is a CPICH (Common Pilot Channel) that transmits a pilot signal for synchronizing with the base station 1 in the mobile station 2.
Each of the downlink 3a and the downlink 3b is subjected to a separation process between channels by applying different spreading codes to transmission data, and then a base station identification code (so-called scramble code) assigned to the base station 1 is applied. Sent.

The uplink 4 includes a DPDCH (Dedicated Physical Data Channel) that is a data channel and a DPCCH (Dedicated Physical Control Channel) that is a control channel, and is transmitted after being IQ-multiplexed.
In the uplink 4, each transmission data is subjected to a different spreading code and subjected to a separation process between channels, then IQ multiplexed, and further a mobile station identification code (so-called scramble code) assigned to the mobile station 2 is applied. Sent.

  On the other hand, in a method of use in which the transmission speed of the downlink 3 is faster than the transmission speed of the uplink 4 represented by the Internet in recent years and a large amount of packet data is transmitted, the base station 1 is connected to the mobile station 2. In addition to the conventional downlink, HSDPA (High Speed Downlink Packet Access) in which a downlink dedicated for high-speed packet transmission is newly added has been proposed and studied in order to realize further speed-up of downlink data transmitted to (For example, refer nonpatent literature 2). FIG. 2 is a configuration diagram showing HSDPA. In the figure, 5 is a downlink dedicated to high-speed packet transmission, and 6 is an uplink. The other components are the same as in FIG.

Next, the operation will be described.
The downlink 5 is transmitted using a so-called shared channel shared by a plurality of mobile stations 2, and HS-DSCH (High Speed-Downlink Shared Channel) that is a data channel and HS-SCCH (High) that is a control data channel. Speed-Shared Control Channel).
In HS-DSCH, AMC (Adaptive Modulation and Coding) that can adaptively change a modulation scheme (for example, QPSK, 16QAM) and an error correction coding rate according to a downlink environment (quality) is adopted. It has been decided. Further, since packet transmission is performed, retransmission control (ARQ: Auto Repeat reQuest) is performed for reception errors.

  Further, both the channels (HS-DSCH, HS-SCCH) are subjected to channel separation and base station identification in the same manner as other downlink (downlink 3a, 3b) channels.

  In addition, when the downlink 5 is newly added, the mobile station 2 transmits response data (ACK / NACK) for downlink high-speed packet data and downlink quality information (QI: Quality Indicator) to the base station 1. As shown in FIG. 2, a dedicated control channel (uplink 6) for transmitting the response data is added.

  The uplink 6 has been studied in the direction of additional IQ multiplexing on the conventional uplink 4 after being separated and identified by a channel separation spreading code in the same manner as the conventional uplink channel. In TR25.858, this dedicated control channel is described as “HS-DPCCH” (High Speed-Dedicated Physical Control Channel).

  The ACK / NACK is transmitted from the mobile station 2 when data is transmitted from the base station 1 on the downlink 5, but the QI is periodically examined in the direction of transmission from the mobile station 2 to the base station 1. ing. Therefore, transmission is performed independently.

  The transmission cycle and timing offset of QI are designated in advance from the base station 1 as parameters, and their values (cycle: k, offset: offset) are described in TR25.858. However, the value and its range are not yet determined and are assumed values for discussion. The assumed value of k is 0, 1, 5, 10, 20, 40, 80, 160, and the range of offset at each k can be 0 ≦ offset ≦ k−1. Further, since k and l are parameters, they can be changed according to the fluctuation speed of the downlink environment during communication.

FIG. 3 is a diagram showing the format of the HS-DPCCH. The HS-DPCCH format will be described below.
An ACK / NACK data area and a QI data area are separated in terms of time, and it has been studied that QI is allocated twice as long as ACK / NACK. Together, both are defined as a unit (subframe) of 2 ms. Subframe is also a transmission unit of HSDPA downlink 5.
The values of the period k and offset are expressed with this Subframe as a unit.

FIG. 4 is a diagram showing extracted QI transmission timing. Here, an example is shown in which there are three mobile stations (MS) assigned with the period k = 5 and one mobile station (MS) assigned with k = 1. Different offsets (= 0, 1, 2) are given to k = 5 mobile stations, and offset = 0 is given to k = 1 mobile stations.
Currently, 0, 1, 5, 10, 20, 40, 80, and 160 are assumed as values of the period k, but no particular basis is shown. It is assumed that k = 0 means no transmission.

  FIG. 5 is a diagram illustrating an example of an assumed internal block diagram of a base station that enables HSDPA, and FIG. 6 is a diagram illustrating an example of an assumed internal block diagram of a mobile station that enables HSDPA. In FIG. 5, 200a, 200b, and 200c are spectrum spreaders, 201a, 201b, and 201c are scramblers, 202 is an adder, 203 is a frequency converter (for transmission), and 204 is a transmission / reception antenna. 205 is an ARQ controller that performs AMC operation and retransmission timing, 206 is a frequency converter (for reception), 207 is a descrambler, 208a and 208b are despreaders, and 209 is a (time) division. 210 is a table for selecting MCS from QI, and 211 is an MCS controller. MCS will be described later.

  In FIG. 6, 300a and 300b are spectrum spreaders, 301a and 301b are scramblers, 302 is an adder, 303 is a frequency converter (for transmission), 304 is a transmission / reception antenna, 305 Is a (time) combiner, 306 is a frequency converter (for reception), 307 is a descrambler, 308a, 308b, and 308c are despreaders, and 309 is a QI transmission controller. , 310 are converters, 311 is a QI transmission timing controller, 312 is a data decision unit, and 313 is an ACK / NACK transmission timing controller.

  5 and 6, parameters (k, offset) for determining the QI transmission timing are transmitted as a part of DPDCH, which is data of a conventional channel, and are notified to the mobile station. Also, as a downlink quality evaluation method, it is assumed here that the CPICH SN ratio evaluated in the mobile station is used. This is because the CPICH is always transmitted with a constant transmission power and the downlink quality can be evaluated.

Next, the transmission operation from the base station and the reception operation at the base station will be described.
The data of CPICH, which is a common channel, and DPDCH / DPCCH, which is a dedicated channel, are spectrum-spread by a known general technique using different channel spreading codes in the spread spectrum spreader 200a and the spread spectrum spreader 200b, respectively. In the unit 201b, a mobile station identification code (scramble code) is multiplied by a known general technique and input to the adder 202.

  The data of HS-DDSCH / HS-SCCH, which is an HSDPA channel, is transmitted from the ARQ controller 205 because the HSDPA channel is a shared channel for transmitting downlinks to a plurality of mobile stations and packet data is transmitted. The transmission timing is controlled. The output of the ARQ controller 205 is spread by a known general technique by the spreader 200c, and then multiplied by a known general technique in the scrambler 201c and input to the adder 202 by a known general technique. The

  The data added by the adder 202 is converted into a radio frequency signal by a known general technique by a frequency converter 203 (for transmission) as a so-called baseband frequency signal, and then transmitted from the transmission / reception antenna 204 to the mobile station. Sent as downlink.

  On the other hand, the radio frequency signal from the mobile station received by the transmission / reception antenna 204 is converted into a baseband signal by a known general technique by the frequency converter 206 (for reception). The baseband signal is multiplied by a scramble code, which is the identification number of the received mobile station, by a known general technique in a descrambler 207.

  The HS-DPCCH is despread by a known general technique by the despreader 208a and extracted as original transmission data, and the (time) divider 209 separates the ACK / NACK data and the QI information data from each other. ACK / NACK data which is a packet response is input to the ARQ controller 205, and retransmission and timing control are performed according to the response.

  The QI data separated by the (time) divider 209 is converted into modulation / coding scheme (MCS) information for packet transmission according to downlink quality (QI) in Table 210. The MCS information output from the table 210 is input to the MCS controller 211. A signal for controlling the AMC operation is input from the MCS controller 211 to the ARQ controller 205, and the AMC operation is performed.

  DPDCH / DPCCH, which is an uplink conventional channel, is despread in despreader 208b and returned to the original transmission data.

Next, the operation of the mobile station will be described with reference to FIG.
First, a transmission operation from the mobile station and a reception operation in the mobile station will be described.
The DPDCH / DPCCH data, which is a conventional channel transmitted from the mobile station, is spread spectrum by a known general technique using a spread code for channel separation in the spread spectrum device 300a, and is then used for identifying the mobile station in the scrambler 301a. The sign is multiplied by a known general technique and input to the adder 302.

HS-DPCCH data (ACK / NACK and QI), which is an HSDPA channel, is time-multiplexed and combined in a (time) synthesizer 305 so as to conform to the format when there is transmission data. After the spectrum is spread by a known general technique using the channel spreading code, the mobile station identification code is multiplied by the known general technique in the scrambler 301b and input to the adder 302.
The outputs of the scrambler 301a and the scrambler 301b added by the adder 302 are converted into radio frequency signals by a known general technique by a frequency converter 303 (for transmission) as a so-called baseband frequency signal. After that, it is transmitted as an uplink from the transmission / reception antenna 304 to the base station.

  On the other hand, the radio frequency signal from the base station received by the transmission / reception antenna 304 is converted into a baseband signal by a known general technique by a (for reception) frequency converter 306. The baseband signal is multiplied by a scramble code which is an identification number of the received base station by a known general technique in a descrambler 307.

The DPDCH / DPCCH, which is a conventional channel, is extracted as original data by being despread by a known general technique by the despreader 308a, and simultaneously input to the QI transmission controller 309 to extract the QI transmission parameters. Hold.
CPICH, which is a common channel, is despread by a general technique known by the despreader 308b. Based on the output of the despreader 308b, the converter 310 calculates the SN ratio of CPICH and creates the QI information data to be transmitted. The QI transmission timing controller 311 uses the parameters of the QI transmission controller 309 based on the parameters. The timing is controlled and transmitted as HS-DPCCH.

As an example of correspondence between the SN ratio of CPICH and QI information data, for example, the base station and the mobile station transmit and receive AMC-controlled data only with QI data by prescribing the relationship shown in Table 1 below in advance in the standard. It is possible.

  HS-SDCH / HS-SCCH, which is an HSDPA channel, is despread by a known general technique by a despreader 308c to extract data. The data determination unit 312 determines whether or not there is an error in the extracted packet data. If there is no error, an ACK is generated. If there is an error, an NACK is generated. The ACK / NACK data is an ACK / NACK transmission timing controller 313. The timing is controlled by and transmitted as HS-DPCCH.

FIG. 7 is a diagram illustrating an example of QI transmission timing in a conventional communication system.
In FIG. 7, three mobile stations with k = 5 have different offset values (offset = 0, 1, 2), and one mobile station with k = 10, with offset = 0, each transmits QI. It shows the state.
The values of k and offset may be different for each mobile station because different values are reported from the base station due to downlink environmental changes and quality for each mobile station.

In this way, when there are mobile stations having different k, if the possible values of k are in a multiple relationship such as 5 and 10, the transmission timing overlaps in a specific combination of mobile stations depending on how offset is given. The probability increases (in FIG. 7, two mobile stations (MS # 1, MS # 4) with offset = 0 overlap).
Further, when the mobile stations are at a short distance, the interference between the mobile stations is increased.

  Since the conventional communication system is configured as described above, there is a problem that interference occurs because possible values (other than 0 and 1) of the QI transmission cycle parameter are in a multiple relationship.

  The present invention has been made to solve the above-described problems, and reduces the probability of transmission collision in a specific combination of mobile stations in a communication system in which the mobile station reports downlink quality information in a variable period. Another object of the present invention is a communication system that reduces interference between mobile stations.

The mobile station according to the present invention is 0 , 1, two or more positive integers that are not in a multiple relationship with each other, and two or more positive integers that are not in a multiple relationship with each other and have a multiple relationship with each other. A receiving unit that receives a transmission cycle selected based on a set including two or more positive integers, and a transmitting unit that transmits downlink quality information based on the transmission cycle received by the receiving unit; The downlink includes a high-speed packet data channel for high-speed packet data transmission, a data channel different from the high-speed packet data channel, and the transmission cycle is transmitted via the data channel .

  According to the present invention, it is possible to reduce a transmission collision probability in a specific combination of mobile stations and to reduce interference between mobile stations.

Hereinafter, in order to describe the present invention in more detail, the best mode for carrying out the present invention will be described with reference to the accompanying drawings.
Embodiment 1 FIG.
FIG. 8 is a diagram showing an example of QI transmission timing of the communication system according to Embodiment 1 of the present invention. Here, it is assumed that kε {0, 1, 5, 11, 19, 41, 83, 161} is defined as an example of a range of values that k can take. In FIG. 8, there are three mobile stations with k = 5 with different offset values (0, 1, 2), and one mobile station with k = 11, with offset = 0, each transmitting QI. It is shown that. On the other hand, in FIG. 7 showing an example of the conventional communication system QI transmission timing, there are three mobile stations with k = 5, different offset values (0, 1, 2), and mobile stations with k = 10. 1 shows a state in which each of the QI transmissions is performed with offset = 0.
The configuration of the communication system according to the first embodiment may be the same as the HSDPA shown in FIG.

Next, the operation will be described.
In the first embodiment, when there are mobile stations having different k, the possible value of k is selected from prime numbers that are not in a multiple relationship such as 5 and 11, so that a period in which transmission collision occurs (The least common multiple of two k (5 and 11)) is 55, which is longer than the least common multiple of 5 and 10 in the conventional communication system. Since the combination changes with time, the probability that transmission timings overlap in a specific mobile station combination is reduced.
In the first embodiment, a value selected from a prime number is used as a possible value of k other than 0 and 1. However, an even number may be used as long as the value does not have a multiple relationship. For example, k = {0, 1, 4, 10, 22,. . . }, An even number of values can be selected, which has the effect of increasing the degree of freedom of base station selection as the value of k.

  Further, in the first embodiment, values selected from prime numbers are used as all possible values of k other than 0 and 1, but when the value of k is large, the collision probability is originally small, The problem is when k takes a small value. Therefore, it is not necessary to select all of the prime numbers, and it is possible to obtain substantially the same effect even if the small value k is selected from the prime numbers and the large value k is designated the same value as the conventional one. Needless to say.

  As described above, the communication system according to the first embodiment moves the quality information (QI) of the downlink (3) from the base station (1) to the mobile station (2) at a changeable period (k). The transmission rate is changed by changing the transmission format of data transmitted from the base station (1) in the downlink (3) based on the transmitted quality information (QI) from the station (2) to the base station (1). In a communication system including a channel (5) to be changed, the value of each cycle (k) of the mobile station (2) is 0, 1, and two or more positive integers that are not in a multiple relationship with each other, and a multiple relationship with each other. Is selected from zero or more positive integers larger than two or more positive integers.

In the communication system of the first embodiment, positive integers of 2 or more that are not in a multiple relationship with each other are prime numbers.
In the above description, Embodiment 1 has been described as a communication system. However, Embodiment 1 may be realized as either a base station or a mobile station that constitutes the communication system.

  The base station of the first embodiment is a period in which the mobile station (2) transmits the quality information (QI) of the downlink (3) from the base station (1) to the mobile station (2) to the base station (1). (K) is selected from a plurality of period candidates including at least two periods that are not in a multiple relationship with each other, and the selected period is indicated to the mobile station (2).

  The mobile station of the first embodiment switches the quality information (QI) of the downlink (3) from the base station (1) to the mobile station (2) by switching at least two periods (k) that are not in a multiple relationship with each other. Can be transmitted to the base station (1).

  In the mobile station of the first embodiment, at least two periods that are not in a multiple relationship with each other are each n times the unit period (k = 1), and n is a positive integer of 2 or more.

  In the mobile station of the first embodiment, the base station (1) changes the data channel modulation scheme used in the downlink (3) together with the DPDCH based on the quality information (QI).

  In the mobile station of the first embodiment, the base station (1) changes the error correction coding rate of the data channel used in the downlink (3) together with the DPDCH based on the quality information (QI).

  As is clear from the above, according to the first embodiment, the period k of each mobile station in a specific combination of mobile stations is set to a value not having a multiple relationship. It is possible to reduce the transmission collision probability and reduce the interference between mobile stations.

  According to the first embodiment, since the cycle k of each mobile station in a specific mobile station combination is a prime number not in a multiple relationship, the transmission collision probability in the specific mobile station combination is reduced, In addition, there is an effect that interference between mobile stations can be reduced.

  According to the first embodiment, the period at which the mobile station transmits downlink quality information from the base station to the mobile station to the base station is determined from a plurality of period candidates including at least two periods that are not in a multiple relationship with each other. Since the selection is made and the selected cycle is instructed to the mobile station, it is possible to reduce the transmission collision probability in a specific combination of mobile stations and to reduce the interference between the mobile stations.

  According to the first embodiment, the downlink quality information from the base station to the mobile station can be transmitted to the base station by switching at least two periods that are not in a multiple relationship with each other. It is possible to reduce the transmission collision probability in the combination of stations and to reduce the interference between mobile stations.

  According to the first embodiment, since at least two periods that are not in a multiple relationship with each other are n times the unit period, and n is a positive integer of 2 or more, a combination of specific mobile stations This reduces the transmission collision probability and reduces the interference between mobile stations.

  According to the first embodiment, since the base station changes the data channel modulation method used in the downlink together with the DPDCH based on the quality information, the transmission collision probability in a specific mobile station combination is reduced. In addition, the inter-mobile station interference can be reduced.

  According to the first embodiment, since the base station changes the error correction coding rate of the data channel used in the downlink together with the DPDCH based on the quality information, the transmission collision in a specific mobile station combination There is an effect that the probability can be reduced and interference between mobile stations can be reduced.

Embodiment 2. FIG.
In the second embodiment, the maximum value k can take is k = {0, 1, 5, 11,. . . , 53} so as not to coincide with the least common multiple of any two k values smaller than the maximum value. This reduces the collision probability to the maximum value of k.
Further, this k = {0, 1, 5, 11,. . . , 53}, the maximum value is smaller than the least common multiple of the two k values smaller than the maximum value, and is the least common multiple of 5 and 11, which are small values other than 0 and 55. Since it is smaller, the collision period is larger than the maximum value of k in any two mobile stations to which any two ks (other than 0 and 1) are assigned, and the probability that the QI transmission collides is also reduced.
In the second embodiment, the value of k taking into consideration the conditions of the first embodiment further reduces the probability of QI transmissions colliding more reliably.

  As described above, in the communication system according to the second embodiment, the mobile station can change the quality information (QI) of the downlink (3) from the base station (1) to the mobile station (2) at a period (k) that can be changed. The transmission rate is changed by changing the transmission format of data transmitted from the base station (1) on the downlink (3) based on the transmitted quality information (QI) from (2) to the base station (1) In the communication system including the channel (5) to be caused, the value of each period (k) of the mobile station (2) is selected from 0, 1, and a positive integer of 2 or more, and the maximum value of the positive integer is It is different from the least common multiple of any two integers of positive integers other than the maximum value.

In the communication system of the second embodiment, the maximum value is smaller than the least common multiple.
As is apparent from the above, according to the second embodiment, the cycle k of each mobile station in a specific combination of mobile stations is selected from 0, 1, and a positive integer of 2 or more. Since the maximum value is different from the least common multiple of any two integers of positive integers other than the maximum value, the collision probability is reduced to the maximum value k.

  According to the second embodiment, the maximum value of positive integers is made smaller than the least common multiple of any two integers of positive integers other than the maximum value. The collision period becomes larger than the maximum value of k, and the probability that the QI transmission collides is reduced.

Embodiment 3 FIG.
In the third embodiment, as a possible value of k (other than 0 and 1), it is assumed that the relationship is defined so that a large k value can be obtained from a small k. The least common multiple + 1 "relationship was assumed. Considering the value of k in this way, 0, 1, 2, 3, 5, 7, 11, 15, 16, 22, 23, 31, 33, 34, 49, and so on are defined in the first embodiment. Since a value similar to the “value not related to the multiple” is obtained, the probability that the QI transmission of a specific mobile station collides is reduced.

Moreover, since a large k can be obtained from a smaller k by setting a unique relationship between a smaller k value and a larger k value, a larger value may be obtained as necessary. In many cases, there is an effect that it is not necessary to store all possible values of k in the base station.
In Embodiment 3, the case of “(the least common multiple of two small k) +1” is shown, but other relations having a similar value of k, for example, “(the least common multiple of two small k)” Needless to say, it may be “+3” or the like.

  As described above, in the communication system according to the third embodiment, the mobile station has a period (k) in which the quality information (QI) of the downlink (3) from the base station (1) to the mobile station (2) can be changed. The transmission rate is changed by changing the transmission format of data transmitted from the base station (1) on the downlink (3) based on the transmitted quality information (QI) from (2) to the base station (1) In the communication system including the channel (5) to be caused, the value of each period (k) of the mobile station (2) is selected from 0, 1, and a positive integer of 2 or more, and the positive integer value is small This is a relationship in which a large value is obtained from the value.

  As is apparent from the above, according to the third embodiment, the cycle k of each mobile station in a specific combination of mobile stations is selected from 0, 1, and a positive integer of 2 or more. Since the relationship is such that the value is obtained from a small value to a large value, the probability that the QI transmission of a specific mobile station collides is reduced, and even if the value of k is large, all the values of k are assigned to the base station. There is an effect that it is not necessary to memorize the value to be obtained.

Embodiment 4 FIG.
FIG. 9 is a diagram showing a communication system according to Embodiment 4 of the present invention. In FIG. 9, 1a, 1b and 1c are base stations, 10a, 10b and 10c are communication ranges (cells) of the base stations 1a, 1b and 1c, 2a and 2b are mobile stations, and 20 is a base station. Inter-station communication lines 6a and 6b are HS-DPCCH transmissions from the mobile stations 2a and 2b, respectively.
In FIG. 9, for easy understanding, the uplink 6 (6 a, 6 b: HS-DPCCH) from the mobile station 2 to the base station 1 among the links (channels) between the base station 1 and the mobile station 2. Only send).

Next, the operation will be described.
In the first to third embodiments, the method of selecting the k value related to the QI transmission timing control for one base station has been shown. However, in this fourth embodiment, there are a plurality of base stations. Consider the case where cells overlap.

  In general, when base stations are arranged, cells are arranged so as to overlap so that communication is not interrupted. In this case, as shown in FIG. 9, in a region where cells overlap, when QI transmission is performed to different base stations 1a and 1b by a plurality of nearby mobile stations 2a and 2b, a set of possible values of k is obtained. In the same case, the interference probability of transmission increases, and at the same time, the interference between mobile stations increases.

At this time, the inter-base station communication line 20 notifies each other of k possible values, and by using different sets of k, the QI transmission collision probability is reduced, and at the same time, the inter-mobile station interference is reduced. Reduced.
In particular, k having a small value that is likely to cause a collision is specified as a different value.
For example, in an extreme case, in the base station 1a, k = {0, 1, 5, 11, 21,..., And in the base station 1b, k = {0, 1, 6, 11, 21,. }, In the base station 1c, even if only the smallest k other than 0 and 1 is changed by the base station as k = {0, 1, 7, 11, 21,. Even if it thinks, the collision probability of QI transmission will be reduced, and the interference between mobile stations will be reduced simultaneously.
In addition, as a method of changing the value that k can take depending on the base station, the values set in the relationship as in the third embodiment are “(the least common multiple of two small k) +1”, “(small two k May be set as follows: (the least common multiple of 2) +2 ”,“ (the least common multiple of two small k) +3 ”.

  Further, in Embodiment 4, the value of the set of k of each base station is notified by the inter-base station communication line 20, but each base station broadcasts information on the value of k and other base stations Other methods may be used such that each base station autonomously sets different sets of k so as to receive.

  As described above, in the communication system according to the fourth embodiment, the mobile station can change the quality information (QI) of the downlink (3) from the base station (1) to the mobile station (2) at a period (k) that can be changed. The transmission rate is changed by changing the transmission format of data transmitted from the base station (1) on the downlink (3) based on the transmitted quality information (QI) from (2) to the base station (1) In the communication system including the channel (5) to be received, the quality information (QI) from the mobile station (2) is received at the period (k) with different values that can be taken by each of the base stations (1). is there.

  In the communication system of the fourth embodiment, the period (k) at which each base station (1) receives quality information (QI) from the mobile station (2) is connected between each base station (1). To be transmitted via the inter-base station communication line (20).

  As is clear from the above, according to the fourth embodiment, the base stations notify each other of information of values that k can take and use different sets of k. As a result, the interference between mobile stations is reduced.

  According to the fourth embodiment, since the period k is transmitted via the inter-base station communication line connecting the base stations, the QI transmission is performed by using different sets of k. As a result, the inter-mobile station interference is reduced at the same time.

It is a block diagram which shows the conventional communication system. It is a block diagram which shows HSDPA. It is a figure which shows the format of HS-DPCCH. It is the figure which extracted and showed the transmission timing of QI. It is a figure which shows an example of the assumed internal block diagram of the base station which enables HSDPA. It is a figure which shows an example of the assumed internal block diagram of the mobile station which enables HSDPA. It is a figure which shows an example of the QI transmission timing of the conventional communication system. It is a figure which shows an example of the QI transmission timing of the communication system by Embodiment 1 of this invention. It is a figure which shows the communication system by Embodiment 4 of this invention.

Claims (9)

0,1, two or more positive not a multiple relationship with each other integers, and said multiple of two or more not in relation positive an integer greater than or equal to 2 or more positive with multiples of each other to each other A receiver for receiving a transmission cycle selected based on a set including an integer ; and
Based on the transmission period received by the reception unit, a transmission unit for transmitting downlink quality information is provided,
The downlink includes a high-speed packet data channel for high-speed packet data transmission, a data channel different from the high-speed packet data channel, and the transmission cycle is transmitted via the data channel. .   The uplink includes a control channel that transmits a response signal corresponding to the reception result of the high-speed packet data transmitted using the high-speed packet data channel, and the transmission unit transmits the quality information using the control channel. The mobile station according to claim 1. Elements of the set 0, 1, 2 or more positive integers that are not in a multiple relationship with each other, and 2 or more positive integers that are not in a multiple relationship with each other and 2 that are in a multiple relationship with each other 2. The mobile station according to claim 1, wherein each of the positive integers equal to or more than one is a value when a transmission cycle is expressed using a parameter having a unit of 2 ms. Based on the notified transmission cycle, the mobile station periodically transmits downlink quality information to the base station.
Transmission cycle of the quality information, 0,1, each other physician two or more positive integer not a multiple relationship, and the multiples to one another be a two or more positive integer value greater than not a multiple of each other Selected based on a set containing two or more positive integers having a relationship;
The downlink includes a high-speed packet data channel for high-speed packet data transmission, a data channel different from the high-speed packet data channel, and the transmission cycle is transmitted via the data channel. . The uplink for transmitting data from the mobile station to the base station includes a control channel for transmitting a response signal to the data transmitted from the base station through a high-speed packet data channel to the base station, and the mobile station uses the control channel. 5. The communication system according to claim 4, wherein the quality information is transmitted to the base station. 5. The communication system according to claim 4, wherein the base station controls a transmission method of the high-speed packet data channel based on quality information transmitted from the mobile station. 0,1, two or more positive not a multiple relationship with each other integers, and said multiple of two or more not in relation positive an integer greater than or equal to 2 or more positive with multiples of each other to each other A period receiving step for receiving a transmission period selected based on a set including integers ;
Based on the transmission period in which downlink quality information is received in the periodic reception step using a control channel in which a mobile station transmits a response signal to the high-speed packet data transmitted by the high-speed packet data channel to the base station. A transmission control method comprising: a transmission step of transmitting to a station . A quality information receiving step of receiving downlink quality information transmitted by the mobile station using a control channel in which the mobile station transmits a response signal to the high-speed packet data transmitted by the high-speed packet data channel ;
0,1, two or more positive not a multiple relationship with each other integers, and said multiple of two or more not in relation positive an integer greater than or equal to 2 or more positive with multiples of each other to each other A transmission control method comprising: a quality information transmission cycle notification step of notifying the mobile station of a transmission cycle of the quality information selected based on a set including an integer . Elements of the set 0, 1, 2 or more positive integers that are not in a multiple relationship with each other, and 2 or more positive integers that are not in a multiple relationship with each other and 2 that are in a multiple relationship with each other 9. The transmission control method according to claim 7, wherein each of the positive integers of more than one is a value when a transmission cycle is expressed using a parameter having a unit of 2 ms.

Images