JP2005318434A - Transmission apparatus and scheduling method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a receiving performance from deteriorating and to realize the most proper signal transmission by setting a diffusion technique along various parameters of a propagation situation of each terminal equipment or the like. <P>SOLUTION: A grouping executer 106 divides each terminal equipment into groups by using an information of a detected result of a delay spread of a feedback information, the information of the detected result of a maximum Doppler frequency, and the information of the measured result of an own cell/other cell interference ratio. A user allocator 108 selects the terminal equipment to allocate a transmission by using a prescribed algorithm each group on the basis of a line quality information included in the feedback information. A diffusion ratio distribution indicator 109 decides the distribution of the diffusion ratio in a time base direction and a frequency base direction each terminal equipment within a range capable of transmitting at a prescribed transmission power and so as for E<SB>b</SB>/N<SB>0</SB>to be minimum. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention particularly relates to a transmission apparatus and a scheduling method using two-dimensional spreading.

  In a transmission system using a multi-carrier CDMA system, spreading is performed in two dimensions, the time axis and the frequency axis, and the spreading factor in the time axis and the spreading factor in the frequency domain are adapted according to the cell configuration, radio parameters, and propagation conditions. What is controlled automatically is known (for example, Non-Patent Document 1). Specifically, frequency selectivity becomes remarkable in an environment with a large delay spread, so if the spreading factor in the frequency domain is large, the orthogonality tends to collapse, and if the moving speed is large, the influence of time fluctuation becomes significant. Since the orthogonality tends to collapse when the diffusion rate of the region is large, a diffusion rate that does not easily collapse the orthogonality is set in consideration of both. That is, the base station sets a spreading factor that is less likely to break orthogonality by utilizing the cell configuration, radio parameters, and propagation conditions. In addition, since the influence of the own cell interference and the diversity effect change depending on the degree of orthogonality breaking, the superiority of time domain spreading and frequency domain spreading changes according to the utilization rate of the spreading code. It is effective to vary the spreading factor for the time domain and the frequency domain so that the required quality is minimized while taking this point into account and the spreading code utilization factor. This makes it possible to utilize high frequency utilization efficiency in multicarrier transmission while maximizing the interference suppression effect due to spreading.

FIG. 15 shows the required average received symbol / energy per noise (hereinafter referred to as “E _s / _M) satisfying the average PER = 10 ⁻² for the code multiplexing number C _mux when the modulation scheme is 16QAM and the coding rate is ½. is a diagram showing an N ₀ "to as) characteristics, FIG. 16, E satisfying average PER = ^{10 -2} for the number of multiplexed codes C _mux when the modulation scheme was set to three quarters of the QPSK and the coding rate is a diagram showing an _s / _{N 0} properties. From FIG. 15, in the region of C _mux <8, the combination using only the spreading in the frequency domain (SF _Freq = 16, SF _Time = 1) can reduce E _s / N _{0 the} most. On the other hand, in the region where C _mux > 8, the combination using only diffusion in the time domain (SF _Freq = 1, SF _Time = 16) can achieve the best characteristics. Further, as shown in FIG. 16, when the number of code multiplexes is small, the effect of reducing E _s / N ₀ increases as the spreading factor SF _Freq in the frequency axis direction increases and the spreading factor SF _Time in the time axis direction decreases. A combination using only spreading in the frequency domain (SF _Freq = 16, SF _Time = 1) can realize the best characteristics.
Noriyuki Maeda, Hiroyuki Shin, Sadayuki Abeda, Mamoru Sawahashi “VSF-OFCDM and its characteristics using two-dimensional diffusion”, IEICE Technical Report, May 2002, p. 59-64

  However, in the conventional transmission device and scheduling method, when there are a plurality of terminal devices that access the same base station, it is common to have different radio parameters and propagation environments for each terminal device, When setting the spreading factor, the effect obtained varies depending on the specifications of which terminal device. That is, for all terminal devices, even if the spreading factor is set according to various parameters indicating the propagation status with the reference terminal device, an appropriate spreading factor is set for other terminal devices with different propagation statuses. There is a problem that the reception performance deteriorates because it is not possible. Specifically, if priority is given to spreading in the time axis direction on the basis of users with high frequency selectivity in a high code utilization rate, reception performance is greatly degraded in terminal devices with high movement speed multiplexed in the same slot. There is a problem of doing.

  The present invention has been made in view of such points, and by setting a spreading factor in accordance with various parameters such as the propagation status of each terminal device, it is possible to prevent the reception performance from deteriorating and each terminal. An object of the present invention is to provide a transmission apparatus and a scheduling method capable of realizing optimal signal transmission for the apparatus.

  The transmission device of the present invention includes a grouping execution unit that classifies a plurality of communication partners into a plurality of groups based on a communication environment with a communication partner, and a predetermined transmission for each group that is grouped by the grouping execution unit. A user allocation unit that selects the communication partner to which transmission is allocated within a range in which transmission can be performed with a transmission power equal to or lower than the power; and a transmission power that is equal to or lower than the transmission power with respect to the communication partner selected by the user allocation unit. Spread rate distribution means for setting a spread rate in the time axis direction and frequency axis direction that can be transmitted in the same manner, and transmission data to be transmitted to the communication partner with the spread rate set in the spread rate distribution means in the time axis direction and Spreading means for spreading in the frequency axis direction, multiplexing means for multiplexing the transmission data for each communication partner spread by the spreading means, and multiple means for multiplexing. It has been adopted a configuration and a transmitting means for transmitting the transmission data.

  According to this configuration, the communication partners are classified into a plurality of groups based on the communication environment with the communication partner, and the spreading factor in the time axis direction and the frequency axis direction is set for each group. By setting the spreading factor according to various parameters such as the propagation state of the signal, it is possible to prevent the reception performance from deteriorating and to realize optimum signal transmission for each communication partner.

  In the transmission apparatus according to the present invention, in the configuration described above, the grouping execution unit stores first grouping information obtained by dividing the delay spread into predetermined ranges, and the delay spread of the communication partner indicating the communication environment is stored. A configuration is adopted in which the communication partner is classified into a plurality of groups for each range by determining the range in which the detection result is included by referring to the first grouping information using the detection result.

According to this configuration, in addition to the above effect, since the delay spread is used as a reference when grouping, parameters such as frequency selectivity, fading time variation, and SNR can be regarded as substantially the same among users in the group. With respect to the E _s / N ₀ characteristic that satisfies a predetermined average PER for the number of multiplexing, an optimum frequency domain and time domain spreading factor according to the number of code multiplexing can be determined. As a result, E _b / N ₀ that satisfies the required quality can be minimized, efficient signal transmission can be performed, and interference with adjacent cells can be reduced.

  In the transmission apparatus according to the present invention, in the configuration described above, the grouping execution unit stores second grouping information obtained by dividing the maximum Doppler frequency for each predetermined range, and the maximum Doppler in the communication partner indicating the communication environment. A configuration is adopted in which the communication partner is classified into a plurality of groups for each range by determining the range in which the detection result is included by referring to the second grouping information using a frequency detection result.

According to this configuration, in addition to the above-described effect, since the maximum Doppler frequency is used as a reference when grouping, parameters such as frequency selectivity, fading time variation, and SNR can be regarded as substantially the same among users in the group. With respect to the E _s / N ₀ characteristic that satisfies a predetermined average PER for the number of code multiplexes, it is possible to determine the optimum frequency domain and time domain spreading factor according to the number of code multiplexes. As a result, E _b / N ₀ that satisfies the required quality can be minimized, efficient signal transmission can be performed, and interference with adjacent cells can be reduced.

  In the transmission apparatus according to the present invention, in the configuration, the grouping execution unit stores the third grouping information obtained by dividing the own cell other cell interference ratio for each predetermined range, and the communication partner indicating the communication environment By referring to the third grouping information using the measurement result of the own cell other cell interference ratio in the above, by determining the range in which the measurement result is included, the communication partners are grouped into a plurality of groups for each range. Use a structure to classify.

According to this configuration, in addition to the above effects, the own cell / other cell interference ratio is used as a reference when grouping, so parameters such as frequency selectivity, fading time variation, and SNR are substantially the same among users in the group. Therefore, regarding the E _s / N ₀ characteristic that satisfies the predetermined average PER for the number of code multiplexes, the optimum frequency domain and time domain spreading factor according to the number of code multiplexes can be determined. As a result, E _b / N ₀ that satisfies the required quality can be minimized, efficient signal transmission can be performed, and interference with adjacent cells can be reduced.

  The transmitting apparatus according to the present invention, in the configuration described above, is characterized in that the grouping execution unit stores fourth grouping information obtained by dividing the modulation multi-value number and the coding rate for each predetermined range, and is line quality information. Stores transmission rate setting information in which channel quality information is associated with the number of modulation levels and the coding rate, and uses the channel quality information indicating the communication environment reported from the communication partner to set the transmission rate. By selecting the modulation multilevel number and the coding rate by referring to the information for use, and by referring to the fourth grouping information using the selected modulation multilevel number and the coding rate, the modulation multilevel The range including the number and the coding rate is determined, and the communication partner is classified into a plurality of groups for each range.

According to this configuration, in addition to the above-described effect, the modulation multi-value number and coding rate are used as a reference when grouping, so parameters relating to resistance to own-cell interference caused by disruption of orthogonality between users in the group Can be regarded as substantially the same, it is possible to determine the optimum frequency domain and time domain spreading factor according to the number of code multiplexes with respect to the E _s / N ₀ characteristic that satisfies a predetermined average PER for the number of code multiplexes. As a result, E _b / N ₀ that satisfies the required quality can be minimized, efficient signal transmission can be performed, and interference with adjacent cells can be reduced.

  In the transmission device according to the present invention, in the configuration described above, the grouping execution unit stores fifth grouping information obtained by dividing required quality and urgency for each predetermined range, and at the communication partner indicating the communication environment. By referring to the fifth grouping information using the required quality information and the urgency level information, the communication partner is determined by determining the range in which the required quality information and the urgency level information are included. The structure which classifies into the several group for every range is taken.

  According to this configuration, in addition to the above effects, communication quality and urgency of communication channels are used as a reference when grouping, so parameters such as allowable delay and maximum number of retransmissions in a group can be regarded as almost the same. It is possible to assign a spreading factor distribution in consideration. As a result, it is possible to simplify the design of the transmission buffer on the wireless network side to cope with various propagation environments.

  The base station apparatus of the present invention employs a configuration including any of the transmission apparatuses described above.

  According to this configuration, since the plurality of terminal devices are classified into a plurality of groups based on the communication environment with the terminal device, and the spreading factor in the time axis direction and the frequency axis direction is set for each group, each terminal device By setting the spreading factor according to various parameters such as the propagation state of the signal, it is possible to prevent the reception performance from deteriorating and to realize optimum signal transmission for each terminal device.

  The scheduling method of the present invention includes a step of classifying a plurality of communication partners into a plurality of groups based on a communication environment with a communication partner, and a range in which transmission can be performed with a transmission power equal to or lower than a predetermined transmission power for each of the grouped groups. Selecting a communication partner to which transmission is assigned, and setting a spreading factor in a time axis direction and a frequency axis direction that can be transmitted to the selected communication partner with a transmission power equal to or lower than the transmission power. It was made to comprise.

  According to this method, a plurality of communication partners are classified into a plurality of groups based on the communication environment with the communication partner, and the spreading factor in the time axis direction and the frequency axis direction is set for each group. By setting the spreading factor according to various parameters such as the propagation state of the signal, it is possible to prevent the reception performance from deteriorating and to realize optimum signal transmission for each communication partner.

  The scheduling method of the present invention stores the first grouping information obtained by dividing the delay spread into predetermined ranges in the method, and uses the detection result of the delay spread in the communication partner indicating the communication environment. The communication partner is classified into a plurality of groups for each range by determining the range in which the detection result is included by referring to one grouping information.

According to this method, in addition to the above effect, since delay spread is used as a reference when grouping, parameters such as frequency selectivity, fading time variation and SNR can be regarded as substantially the same among users in the group. With respect to the E _s / N ₀ characteristic that satisfies a predetermined average PER for the number of multiplexing, an optimum frequency domain and time domain spreading factor according to the number of code multiplexing can be determined. As a result, E _b / N ₀ that satisfies the required quality can be minimized, efficient signal transmission can be performed, and interference with adjacent cells can be reduced.

  The scheduling method of the present invention stores the second grouping information obtained by dividing the maximum Doppler frequency into predetermined ranges in the method, and uses the detection result of the maximum Doppler frequency in the communication partner indicating the communication environment. By referring to the second grouping information, the communication partner is classified into a plurality of groups for each range by determining the range in which the detection result is included.

According to this method, in addition to the above-described effect, since the maximum Doppler frequency is used as a reference when grouping, parameters such as frequency selectivity, fading time variation, and SNR can be regarded as substantially the same among users in the group. With respect to the E _s / N ₀ characteristic that satisfies a predetermined average PER for the number of code multiplexes, it is possible to determine the optimum frequency domain and time domain spreading factor according to the number of code multiplexes. As a result, E _b / N ₀ that satisfies the required quality can be minimized, efficient signal transmission can be performed, and interference with adjacent cells can be reduced.

  The scheduling method of the present invention stores the third grouping information obtained by dividing the own cell / other cell interference ratio for each predetermined range in the method, and the own cell / other cell interference ratio in the communication partner indicating the communication environment. By referring to the third grouping information using the measurement result, the communication partner is classified into a plurality of groups for each range by determining the range in which the measurement result is included.

According to this method, in addition to the effects described above, the own cell other cell interference ratio is used as a reference when grouping, so parameters such as frequency selectivity, fading time variation, and SNR are substantially the same among users in the group. Therefore, regarding the E _s / N ₀ characteristic that satisfies the predetermined average PER for the number of code multiplexes, the optimum frequency domain and time domain spreading factor according to the number of code multiplexes can be determined. As a result, E _b / N ₀ that satisfies the required quality can be minimized, efficient signal transmission can be performed, and interference with adjacent cells can be reduced.

  The scheduling method of the present invention stores the fourth grouping information obtained by dividing the modulation multi-value number and the coding rate for each predetermined range in the above method, and the channel quality information as the channel quality information and the modulation multi-value. By storing transmission rate selection information relating the number of values and coding rate, and referring to the transmission rate selection information using the channel quality information indicating the communication environment reported from the communication partner By selecting a modulation multi-value number and a coding rate, and referring to the fourth grouping information using the selected modulation multi-value number and the coding rate, the modulation multi-value number and the coding rate are The range included is determined, and the communication partner is classified into a plurality of groups for each range.

According to this method, in addition to the above-described effect, the modulation multi-value number and coding rate are used as a reference when grouping, so parameters relating to resistance to own-cell interference caused by disruption of orthogonality between users in the group Can be regarded as substantially the same, it is possible to determine the optimum frequency domain and time domain spreading factor according to the number of code multiplexes with respect to the E _s / N ₀ characteristic that satisfies a predetermined average PER for the number of code multiplexes. As a result, E _b / N ₀ that satisfies the required quality can be minimized, efficient signal transmission can be performed, and interference with adjacent cells can be reduced.

  The scheduling method of the present invention stores the fifth grouping information obtained by dividing the required quality and the urgency level for each predetermined range in the method, and the required quality information and the urgency level at the communication partner indicating the communication environment. By referring to the fifth grouping information using the information of the above, by determining the range in which the required quality information and the urgency information are included, the communication partner is divided into a plurality of groups for each range. It was made to classify.

  According to this method, in addition to the above effects, communication quality and urgency of communication channels are used as a reference when grouping, so parameters such as allowable delay and maximum number of retransmissions within a group can be regarded as almost the same. It is possible to assign a spreading factor distribution in consideration. As a result, it is possible to simplify the design of the transmission buffer on the wireless network side to cope with various propagation environments.

  The transmission method of the present invention includes a step of classifying a plurality of communication partners into a plurality of groups based on a communication environment with a communication partner, and a range in which transmission can be performed with a transmission power equal to or lower than a predetermined transmission power for each of the grouped groups. Selecting a communication partner to which transmission is assigned, and setting a spreading factor in a time axis direction and a frequency axis direction that can be transmitted to the selected communication partner with a transmission power equal to or lower than the transmission power. A step of spreading transmission data to be transmitted to the communication partner at a set spreading factor in a time axis direction and a frequency axis direction, a step of multiplexing the transmission data for each communication partner that has been spread, Transmitting the transmitted data.

  According to this method, a plurality of communication partners are classified into a plurality of groups based on the communication environment with the communication partner, and the spreading factor in the time axis direction and the frequency axis direction is set for each group. By setting the spreading factor according to various parameters such as the propagation state of the signal, it is possible to prevent the reception performance from deteriorating and to realize optimum signal transmission for each communication partner.

  ADVANTAGE OF THE INVENTION According to this invention, while setting the spreading factor according to various parameters, such as the propagation condition of each terminal device, it can prevent that reception performance deteriorates, and optimal signal transmission with respect to each terminal device Can be realized.

  The gist of the present invention is to classify a plurality of terminal devices into a plurality of groups based on the communication environment with the terminal device, and within a range where transmission can be performed with transmission power equal to or lower than a predetermined transmission power for each grouped group. It is to select a terminal device to which transmission is assigned and to set a spreading factor in the time axis direction and the frequency axis direction that can be transmitted to the selected terminal device with transmission power equal to or lower than a predetermined transmission power.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a block diagram showing a configuration of transmitting apparatus 100 according to Embodiment 1 of the present invention. The transmission signal generating unit 111 and the spreading unit 112 constitute transmission data processing units 115-1 to 115-n. The transmission data processing units 115-1 to 115-n are provided for each terminal device. In FIG. 1, the transmission data processing units 115-1 to 115-n all have the same configuration, and thus the description of the transmission data processing units 115-2 to 115-n is omitted.

  The antenna 101 outputs the received reception signal to the reception RF unit 102, and transmits the transmission signal input from the transmission RF unit 114.

  Reception RF section 102 down-converts the reception signal input from antenna 101 from a radio frequency to a baseband frequency and outputs the result to reception signal demodulation section 103.

  Reception signal demodulating section 103 demodulates the reception signal input from reception RF section 102 and outputs the demodulated signal to feedback information reference section 104 and obtains reception data.

  Feedback information reference section 104 extracts feedback information from the received data input from received signal demodulation section 103. Then, feedback information reference section 104 outputs the extracted feedback information to grouping execution section 106. Here, the feedback information includes information on the detection result of the delay spread detected by the terminal device, information on the detection result of the maximum Doppler frequency, information on the measurement result of the own cell other cell interference ratio, for example, CQI (Channel Quality Indicator). Such as channel quality information, which is information indicating the channel quality with the terminal device, information on the quality of the communication channel for the terminal device, information on the urgency level of the communication channel for the terminal device, and the like.

  The grouping reference instruction unit 105 stores a table storing grouping information in which threshold values are provided for each predetermined range for the delay spread, the maximum Doppler frequency, and the own cell other cell interference ratio.

  The grouping execution unit 106 uses the information on the delay spread detection result of the feedback information input from the feedback information reference unit 104, the information on the detection result of the maximum Doppler frequency, and the information on the measurement result of the own cell other cell interference ratio. The terminal devices are grouped with reference to the grouping information stored in the grouping criterion instructing unit 105. Thereby, each terminal device can be divided into several groups with similar characteristics. Then, the grouping execution unit 106 outputs group information, which is information on the result of grouping, to the user allocation unit 108. A method for grouping will be described later.

  The radio resource management unit 107 manages resources of the entire radio network, and outputs resource information, which is transmission power information that can be set according to each condition, to the user allocation unit 108 and the spreading factor allocation instruction unit 109.

  Based on the channel quality information and group information included in the feedback information input from the grouping execution unit 106, the user allocation unit 108 selects a terminal device to which transmission is allocated for each group using a predetermined algorithm. Specifically, the user allocation unit 108 stores a table storing transmission rate setting information that associates channel quality information with a coding rate, a modulation scheme, and the number of codes, and is included in feedback information. Using the channel quality information, select the coding rate, modulation scheme, and number of codes for the terminal device selected for each group so that the transmission power is equal to or lower than the transmission power of the resource information input from the radio resource management unit 107 And assign the transmission. In addition, as an algorithm for assigning transmission to the terminal device, the user assigning unit 108 preferentially assigns the terminal device having the highest quality, MaxCIR to be assigned, RoundRobin to randomly assign the terminal device, or quality for each terminal device. ProportionalFairness assigned at a timing suitable for the corresponding terminal device is used by looking at the time variation. Then, user allocation section 108 outputs allocation information, which is information on the terminal apparatus to which transmission is allocated, to spreading factor allocation instructing section 109.

The spreading factor allocation instructing unit 109 uses the allocation information input from the user allocation unit 108 and the resource information input from the radio resource management unit 107 to apply a coding rate and a modulation multi-level number applicable to the terminal device to which transmission is allocated. And the total number of codes, or any one or two of the codes, are added between the terminal devices, and within a range in which transmission can be performed with a predetermined transmission power, and a desired power density to noise power density ratio per bit (hereinafter referred to as a ratio) The distribution of the spreading factor in the time axis direction and the frequency axis direction is determined so that “E _b / N ₀ ” is minimized. Then, spreading factor allocation instructing section 109 outputs spreading factor allocation information, which is information on the determined spreading factor allocation, to spreading factor allocation section 110. Also, spreading factor allocation instructing section 109 outputs spreading factor allocation information of each terminal apparatus to transmission signal generating section 111 of corresponding transmission data processing sections 115-1 to 115-n.

  The spreading factor distribution unit 110 performs the spreading process on the spreading unit 112 of each of the transmission data processing units 115-1 to 115-n so as to perform spreading processing according to the spreading factor distribution of the spreading factor distribution information input from the spreading factor allocation instruction unit 109. Instruct.

  The transmission signal generation unit 111 generates a transmission signal including its own spreading factor distribution information input from the spreading factor allocation instruction unit 109 in the transmission data, and outputs the transmission signal to the spreading unit 112.

  The spreading unit 112 performs spreading processing on the transmission signal input from the transmission signal generating unit 111 with the spreading factor instructed by the spreading factor distribution unit 110 and outputs the result to the user multiplexing unit 113.

  The user multiplexing unit 113 multiplexes the transmission signals input from the spreading units 112 of the transmission data processing units 115-1 to 115-n and outputs the multiplexed signals to the transmission RF unit 114.

  The transmission RF unit 114 up-converts the transmission signal input from the user multiplexing unit 113 from the baseband frequency to the radio frequency and outputs it to the antenna 101.

  Next, the configuration of the terminal device 200 will be described with reference to FIG. FIG. 2 is a block diagram illustrating a configuration of the terminal device 200.

  The antenna 201 outputs the received signal received to the reception RF unit 202 and transmits the transmission signal input from the transmission RF unit 208.

  The reception RF unit 202 down-converts the reception signal input from the antenna 201 from the radio frequency to the baseband frequency, and outputs it to the reception signal demodulation unit 204 and the control information demodulation unit 203.

  Control information demodulation section 203 demodulates control information multiplexed by a prescribed method from the received signal input from reception RF section 202, and outputs spreading factor distribution information included in the control information to received signal demodulation section 204 To do.

  The received signal demodulator 204 despreads and demodulates the received signal input from the received RF unit 202 with reference to the spreading factor of the spreading factor distribution information input from the control information demodulator 203. Then, reception signal demodulating section 204 outputs the received data of the communication channel in the demodulated reception signal to communication channel decoding section 205, and outputs the reference signal in the demodulated reception signal to reference signal observation section 206.

  The communication channel decoding unit 205 decodes the demodulated communication channel reception data input from the reception signal demodulation unit 204 by turbo decoding or the like to obtain reception data.

  The reference signal observation unit 206 observes the propagation state using the reference signal input from the reception signal demodulation unit 204. Then, the reference signal observation unit 206 generates channel quality information, which is information indicating the observed propagation status, and outputs the channel quality information to the feedback information generation unit 207.

  The feedback information generation unit 207 generates a delay profile and detects a delay spread to generate delay spread information, detects a maximum Doppler frequency to generate information on the maximum Doppler frequency, Measurement is performed to generate information on the own cell / other cell interference ratio, measurement of required quality and generation of required quality information, and generation of urgency information. Then, the feedback information generation unit 207 receives the channel quality information, the delay spread information, the maximum Doppler frequency information, the own cell other cell interference ratio information, the required quality information, and the urgency information input from the reference signal observation unit 206. Is output to the transmission RF section 208 as feedback information.

  Transmission RF section 208 up-converts feedback information input from feedback information generation section 207 from a baseband frequency to a radio frequency and outputs the result to antenna 201.

  Next, a scheduling method performed by transmission apparatus 100 will be described. The grouping reference instruction unit 105 stores a table storing grouping information as shown in FIGS. That is, the grouping criterion instructing unit 105 stores delay spread information as shown in FIG. 3, maximum Doppler frequency information as shown in FIG. 4, and own cell other cell interference ratio information as shown in FIG. doing.

  Then, the grouping execution unit 106 uses the delay spread information, the maximum Doppler frequency information, and the own cell other cell interference ratio information included in the feedback information to refer to FIGS. As shown, the terminal devices 200 having the delay spread x1, the maximum Doppler frequency y1, and the own cell other cell interference ratio z1 are classified into the group A, and the delay spread x2, the maximum Doppler frequency y2, and the own cell other cell interference ratio z2 are obtained. The terminal device 200 is classified into group B. The grouping is performed in the same manner after group C.

  Next, for example, when the grouping execution unit 106 groups the seven terminal devices 200 A1 to A7 into the A group, the user allocation unit 108 considers resource information and the transmission power is equal to or lower than a predetermined transmission power. Thus, transmission is assigned to the three terminal devices 200 of A2, A5, and A7 from among the terminal devices 200 of A1 to A7.

  Next, the user allocation unit 108 stores a table storing transmission rate setting information as shown in FIG. When the terminal apparatus 200 of A2 has reported CQI = 8, the user allocation unit 108 uses the number of codes 5, modulation scheme 16QAM and coding rate 2 for the terminal apparatus 200 of A2 from FIG. Assign a fraction of a minute. When the A5 terminal apparatus 200 reports CQI = 4, the user allocation unit 108 determines that the number of codes is 4, the modulation scheme QPSK, and the coding rate 3 for the A5 terminal apparatus 200 from FIG. Assign a fraction of a minute. Further, when the A7 terminal apparatus 200 reports CQI = 9, the user allocation unit 108 compares the number of codes 5, modulation scheme 16QAM, and coding rate 4 with respect to the A7 terminal apparatus 200 from FIG. Allocate 3 minutes.

  Next, the spreading factor distribution instructing unit 109 spreads the time domain 8 times and the frequency domain 2 times according to the number of codes allocated to each terminal device 200 for the terminal devices 200 of A2, A5, and A7. Information is generated and output to spreading factor distribution section 110, and also output to transmission signal generation section 111 of transmission data processing sections 115-1 to 115-n corresponding to terminal apparatuses 200 of A2, A5, and A7. Note that the same scheduling as in group A is performed after group B.

  As described above, according to the first embodiment, the terminal devices are grouped based on various parameters such as the delay spread of each terminal device, the maximum Doppler frequency, and the own cell other cell interference ratio, and the time axis direction and frequency. Since the spreading factor in the axial direction is set, it is possible to prevent the reception performance from deteriorating and to realize optimum signal transmission for each terminal device.

Further, according to the first embodiment, since the delay spread, the maximum Doppler frequency, and the own cell other cell interference ratio are used as a reference when grouping, frequency selectivity, fading time variation, SNR, etc. among users in the group Therefore, the optimum spreading factor in the frequency domain and time domain according to the number of code multiplexes can be determined for the E _s / N ₀ characteristic that satisfies a predetermined average PER for the number of code multiplexes. As a result, E _b / N ₀ that satisfies the required quality can be minimized, efficient signal transmission can be performed, and interference with adjacent cells can be reduced.

  In the first embodiment, the terminal devices are grouped using the delay spread, the maximum Doppler frequency, and the own cell other cell interference ratio. However, the present invention is not limited to this, and the delay spread, the maximum Doppler frequency, Each terminal device may be grouped by selecting any one or any two of the cell-to-cell interference ratios.

(Embodiment 2)
FIG. 8 is a block diagram showing the configuration of the grouping execution unit 106 according to Embodiment 2 of the present invention. Note that the transmission apparatus according to the second embodiment has the same configuration as that of the transmission apparatus 100 according to the first embodiment shown in FIG.

  The selection unit 801 stores a table in which transmission rate setting information as illustrated in FIG. 7 is stored, and transmission rate setting information is used using channel quality information included in the feedback information input from the feedback information reference unit 104. The modulation scheme and coding rate are selected by referring to FIG. Then, the selection unit 801 outputs the selected modulation scheme and coding rate information to the grouping unit 802.

  The grouping unit 802 uses the modulation scheme and coding rate information input from the selection unit 801 to group the terminal devices with reference to the grouping information stored in the grouping criterion instructing unit 105. Thereby, each terminal device can be divided into several groups with similar characteristics. Then, the grouping unit 802 outputs group information, which is information on the result of grouping, to the user allocation unit 108.

  Next, a scheduling method performed by the transmission apparatus will be described. FIG. 9 shows grouping information about the modulation multi-level number stored in the grouping reference instruction unit 105, and FIG. 10 shows the coding rate stored in the grouping reference instruction unit 105. Indicates grouping information. In FIG. 9, QPSK has a modulation multilevel number of 2, and 16QAM has a modulation multilevel number of 4.

  The grouping execution unit 106 stores a table storing transmission rate setting information as shown in FIG. Then, the grouping execution unit 106 selects the modulation scheme and coding rate by referring to the transmission rate setting information of FIG. 7 using the channel quality information included in the feedback information, as shown in FIG. The terminal device 200 having the modulation multilevel number a1 and the coding rate b1 is classified into the group A, and the terminal device 200 having the modulation multilevel number a2 and the coding rate b2 is classified into the group B. The grouping is performed in the same manner after group C.

  Next, for example, when the grouping execution unit 106 groups the seven terminal devices 200 A1 to A7 into the A group, the user allocation unit 108 considers resource information and the transmission power is equal to or lower than a predetermined transmission power. Thus, transmission is assigned to the three terminal devices 200 of A2, A5, and A7 from among the terminal devices 200 of A1 to A7.

  Next, the user allocation unit 108 stores a table storing transmission rate setting information as shown in FIG. Then, when the terminal devices 200 of A2, A5, and A7 have reported CQI = 4, the user allocation unit 108 determines that the number of codes 4, modulation scheme QPSK, and Assign a coding rate of 1/3.

  Next, the spreading factor distribution instructing unit 109 spreads the time domain 8 times and the frequency domain 2 times according to the number of codes allocated to each terminal device 200 for the terminal devices 200 of A2, A5, and A7. Information is generated and output to spreading factor distribution section 110, and also output to transmission signal generation section 111 of transmission data processing sections 115-1 to 115-n corresponding to terminal apparatuses 200 of A2, A5, and A7. Note that the same scheduling as in group A is performed after group B.

  As described above, according to the second embodiment, the terminal devices are grouped based on various parameters such as the modulation multi-level number and the coding rate of each terminal device, and spread in the time axis direction and the frequency axis direction. Since the rate is set, it is possible to prevent the reception performance from deteriorating and to realize optimum signal transmission for each terminal device.

Further, according to the second embodiment, since the modulation multi-level number and the coding rate are used as a reference when grouping, a parameter relating to resistance to own cell interference caused by disruption of orthogonality among users in the group is provided. Since they can be regarded as being substantially the same, it is possible to determine the optimum frequency domain and time domain spreading factor according to the number of code multiplexes with respect to the E _s / N ₀ characteristic that satisfies a predetermined average PER for the number of code multiplexes. As a result, E _b / N ₀ that satisfies the required quality can be minimized, efficient signal transmission can be performed, and interference with adjacent cells can be reduced.

(Embodiment 3)
12 and 13 are diagrams showing grouping information according to Embodiment 3 of the present invention. The transmitting apparatus according to the third embodiment has the same configuration as that of transmitting apparatus 100 according to the first embodiment shown in FIG.

  A scheduling method performed by the transmission apparatus will be described. The grouping reference instruction unit 105 stores a table storing grouping information as shown in FIGS. That is, the grouping reference instruction unit 105 stores information on required quality as shown in FIG. 12 and information on urgency as shown in FIG.

  Then, the grouping execution unit 106 uses the error rate information and the urgency information indicating the required quality included in the feedback information to refer to FIGS. Is classified into group A, and terminal device 200 with required quality c2 and urgency d2 is classified into group B. The grouping is performed in the same manner after group C. The information indicating the required quality is not limited to the error rate, and an arbitrary value can be used.

  Next, for example, when the grouping execution unit 106 groups the seven terminal devices 200 A1 to A7 into the A group, the user allocation unit 108 considers resource information and the transmission power is equal to or lower than a predetermined transmission power. Thus, transmission is assigned to the three terminal devices 200 of A2, A5, and A7 from among the terminal devices 200 of A1 to A7.

  Next, the user allocation unit 108 stores a table storing transmission rate setting information as shown in FIG. When the terminal apparatus 200 of A2 has reported CQI = 8, the user allocation unit 108 uses the number of codes 5, modulation scheme 16QAM and coding rate 2 for the terminal apparatus 200 of A2 from FIG. Assign a fraction of a minute. When the A5 terminal apparatus 200 reports CQI = 4, the user allocation unit 108 determines that the number of codes is 4, the modulation scheme QPSK, and the coding rate 3 for the A5 terminal apparatus 200 from FIG. Assign a fraction of a minute. Further, when the A7 terminal apparatus 200 reports CQI = 9, the user allocation unit 108 compares the number of codes 5, modulation scheme 16QAM, and coding rate 4 with respect to the A7 terminal apparatus 200 from FIG. Allocate 3 minutes.

  Next, the spreading factor distribution instructing unit 109 spreads the time domain 8 times and the frequency domain 2 times according to the number of codes allocated to each terminal device 200 for the terminal devices 200 of A2, A5, and A7. Information is generated and output to spreading factor distribution section 110, and also output to transmission signal generation section 111 of transmission data processing sections 115-1 to 115-n corresponding to terminal apparatuses 200 of A2, A5, and A7. Note that the same scheduling as in group A is performed after group B.

  Thus, according to the third embodiment, after the terminal devices are grouped based on various parameters such as required quality and urgency of each terminal device, the time axis direction and the frequency axis direction are grouped. Therefore, it is possible to prevent the reception performance from deteriorating and to realize optimum signal transmission for each terminal device.

  Also, according to the third embodiment, since communication quality and urgency of communication channels are used as a reference when grouping, parameters such as allowable delay and maximum number of retransmissions within a group can be regarded as substantially the same, and therefore these are considered. Can be assigned to the spread rate distribution. As a result, it is possible to simplify the design of the transmission buffer on the wireless network side to cope with various propagation environments.

  In the above embodiment, each terminal apparatus is grouped using the delay spread, the maximum Doppler frequency, the own cell other cell interference ratio, the modulation multi-level number, the coding rate, the required quality of the communication channel, and the urgency level. Not limited to this, the terminal devices can be grouped using arbitrary parameters.

  The transmission apparatus and the scheduling method according to the present invention can prevent the reception performance from deteriorating by setting the spreading factor according to various parameters such as the propagation status of each terminal apparatus, and for each terminal apparatus. Therefore, it is useful for performing two-dimensional spreading by variably setting the spreading factor.

The block diagram which shows the structure of the transmitter which concerns on Embodiment 1 of this invention. The block diagram which shows the structure of the terminal device which concerns on Embodiment 1 of this invention. The figure which shows the grouping information which concerns on Embodiment 1 of this invention The figure which shows the grouping information which concerns on Embodiment 1 of this invention The figure which shows the grouping information which concerns on Embodiment 1 of this invention The figure which shows the method of grouping based on Embodiment 1 of this invention The figure which shows the information for transmission rate setting which concerns on Embodiment 1 of this invention. The figure which shows the structure of the grouping implementation part which concerns on Embodiment 2 of this invention. The figure which shows the grouping information which concerns on Embodiment 2 of this invention The figure which shows the grouping information which concerns on Embodiment 2 of this invention The figure which shows the method of grouping based on Embodiment 2 of this invention The figure which shows the grouping information which concerns on Embodiment 3 of this invention. The figure which shows the grouping information which concerns on Embodiment 3 of this invention. The figure which shows the method of grouping based on Embodiment 3 of this invention Shows the _E s / _{N 0} characteristic for the number of multiplexed codes Shows the _E s / _{N 0} characteristic for the number of multiplexed codes

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Transmission apparatus 101 Antenna 102 Reception RF part 103 Received signal demodulation part 104 Feedback information reference part 105 Grouping standard instruction | indication part 106 Grouping execution part 107 Radio resource management part 108 User allocation part 109 Spreading factor allocation instruction part 110 Spreading factor distribution part 111 Transmission Signal Generation Unit 112 Spreading Unit 113 User Multiplexing Unit 114 Transmission RF Unit

Claims (14)

Grouping means for classifying a plurality of communication partners into a plurality of groups based on a communication environment with the communication partner;
User assignment means for selecting the communication partner to which transmission is assigned within a range in which transmission can be performed with transmission power equal to or lower than predetermined transmission power for each group grouped by the grouping execution means;
Spreading factor distribution means for setting spreading factors in the time axis direction and the frequency axis direction that can be transmitted at a transmission power equal to or lower than the transmission power to the communication partner selected by the user allocation means;
Spreading means for spreading the transmission data to be transmitted to the communication partner at the spreading factor set by the spreading factor distribution means in the time axis direction and the frequency axis direction;
Multiplexing means for multiplexing transmission data for each of the communication partners subjected to spreading processing by the spreading means;
Transmitting means for transmitting the transmission data multiplexed by the multiplexing means;
A transmission device comprising:   The grouping execution unit stores first grouping information obtained by dividing a delay spread into predetermined ranges, and uses the detection result of the delay spread in the communication partner indicating the communication environment to determine the first grouping information. The transmission apparatus according to claim 1, wherein the communication partner is classified into a plurality of groups for each range by determining the range in which the detection result is included by referring to.   The grouping execution means stores second grouping information obtained by dividing the maximum Doppler frequency for each predetermined range, and uses the detection result of the maximum Doppler frequency in the communication partner indicating the communication environment to detect the second group. The transmission according to claim 1 or 2, wherein the communication partner is classified into a plurality of groups for each of the ranges by determining the range including the detection result by referring to the division information. apparatus.   The grouping execution means stores the third grouping information obtained by dividing the own cell other cell interference ratio for each predetermined range, and displays the measurement result of the own cell other cell interference ratio in the communication partner indicating the communication environment. The communication partner is classified into a plurality of groups for each range by determining the range in which the measurement result is included by referring to the third grouping information. The transmission device according to claim 3.   The grouping execution means stores the fourth grouping information obtained by dividing the modulation multilevel number and the coding rate for each predetermined range, and also includes channel quality information, which is channel quality information, the modulation multilevel number, and the code. The transmission rate setting information associated with the conversion rate, and by referring to the transmission rate setting information using the line quality information indicating the communication environment reported from the communication partner, The range including the modulation multi-value number and the coding rate by selecting the coding rate and referring to the fourth grouping information using the selected modulation multi-value number and the coding rate. The transmission apparatus according to claim 1, wherein the communication partner is classified into a plurality of groups for each of the ranges.   The grouping execution means stores fifth grouping information obtained by dividing required quality and urgency for each predetermined range, and uses required quality information and urgency information in the communication partner indicating the communication environment. Classifying the communication partner into a plurality of groups for each range by determining the range including the required quality information and the urgency level information by referring to the fifth grouping information. The transmission apparatus according to claim 1, wherein the transmission apparatus is characterized.   A base station apparatus comprising the transmission apparatus according to any one of claims 1 to 6. Classifying a plurality of communication partners into a plurality of groups based on a communication environment with the communication partners;
Selecting the communication partner to which transmission is assigned within a range in which transmission can be performed with transmission power equal to or lower than predetermined transmission power for each group divided;
Setting a spreading factor in a time axis direction and a frequency axis direction that can be transmitted at a transmission power equal to or lower than the transmission power to the selected communication partner;
A scheduling method comprising:   By storing the first grouping information obtained by dividing the delay spread for each predetermined range, and by referring to the first grouping information using the detection result of the delay spread in the communication partner indicating the communication environment, 9. The scheduling method according to claim 8, wherein the communication partner is classified into a plurality of groups for each range by determining the range including the detection result.   By storing the second grouping information obtained by dividing the maximum Doppler frequency for each predetermined range, and by referring to the second grouping information using the detection result of the maximum Doppler frequency in the communication partner indicating the communication environment 10. The scheduling method according to claim 8, wherein the communication partner is classified into a plurality of groups for each range by determining the range including the detection result.   Stores third grouping information obtained by dividing the own cell other cell interference ratio for each predetermined range, and uses the measurement result of the own cell other cell interference ratio in the communication partner indicating the communication environment to perform the third grouping. 11. The communication partner is classified into a plurality of groups for each range by determining the range in which the measurement result is included by referring to information. The scheduling method described.   Stores the fourth grouping information obtained by dividing the modulation multi-level number and the coding rate for each predetermined range, and associates the channel quality information, which is channel quality information, with the modulation multi-level number and the coding rate. The transmission rate selection information is stored, and the modulation multi-value number and the coding rate are selected by referring to the transmission rate selection information using the channel quality information indicating the communication environment reported from the communication partner. The communication partner is determined by referring to the fourth grouping information using the selected modulation multi-level number and the coding rate, and determining the range including the modulation multi-level number and the coding rate. 12. The scheduling method according to claim 8, wherein the scheduling method is classified into a plurality of groups for each range.   The fifth grouping information is stored using the required quality information and the urgency information in the communication partner indicating the communication environment, while storing the fifth grouping information in which the required quality and the urgency level are divided into predetermined ranges. 9. The communication partner is classified into a plurality of groups for each range by determining the range including the required quality information and the urgency level information by referring to FIG. The scheduling method according to claim 12. Classifying a plurality of communication partners into a plurality of groups based on a communication environment with the communication partners;
Selecting the communication partner to which transmission is assigned within a range in which transmission can be performed with transmission power equal to or lower than predetermined transmission power for each group divided;
Setting a spreading factor in a time axis direction and a frequency axis direction that can be transmitted at a transmission power equal to or lower than the transmission power to the selected communication partner;
Spreading transmission data to be transmitted to the communication partner at a set spreading factor in a time axis direction and a frequency axis direction;
Multiplexing the transmission data for each communication partner that has been spread;
Transmitting the transmission data multiplexed; and
The transmission method characterized by comprising.

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