CN101019358A - Wireless communication apparatus and wireless communication method - Google Patents

Abstract

A wireless communication apparatus wherein the data amount of feedback information can be reduced, while a high throughput being maintained. In this apparatus, a CSI (Channel State Information) processing part (38) generates a CSI frame based on an SNR (Signal power to Noise power Ratio) for each of measured subcarriers, and a CSI transmission control part (39) generates a timing signal and control information required for generating the CSI frame, and controls the CSI processing part (38). The CSI processing part (38) generates a first frame (CSI1), which comprises the CSI of a subcarrier whose SNR variation amount is less than a threshold value, in a generation period that is greater than the generation period of a second frame (CSI2) comprising the CSI of a subcarrier whose SNR variation amount is equal to or greater than the threshold value.

Description

Radio communication device and wireless communications method

Technical field

The present invention relates to a kind of radio communication device and wireless communications method.

Background technology

In the next generation mobile communication system in the 4th generation etc., require when high-speed mobile, also can surpass the data rate of 100Mbps.For meeting this requirement, the various radio communications of using the bandwidth about 100MHz have been discussed.Wherein, from to the adaptability of frequency selective fading environment and the viewpoint of frequency utilization efficient, be that the multicarrier transmission mode of representative is expected especially as the transmission means of next generation mobile communication system in OFDM (Orthogonal Frequency Division Multiplexing) mode.

In the past, in order in the communication system of the multicarrier transmission mode that uses OFDM etc., to obtain high-throughput, following technology is discussed, promptly, use pilot signal etc. is estimated each subcarrier or the line status that gathers each frequency range (segment) of a plurality of subcarriers, each subcarrier (frequency range) is determined and sends the technology of the modulation parameter of error correcting capability, order of modulation, power, phase place, transmitting antenna etc. according to the information (Channel State Information:CSI) of this line status of expression.

For example, during to each subcarrier (frequency range) control modulation parameter, the feedback information of CSI of each subcarrier (frequency range) or modulation parameter etc. is transmitted.Therefore, the number of subcarrier (frequency range) is many more, and it is big more that it feeds back needed data volume, and the expense of feedback information increases.

In addition, along with moving of travelling carriage and moving of peripheral object, transmission path characteristic changes in time.This time fluctuation amount and translational speed and carrier frequency are proportional.When the time fluctuation amount of transmission path characteristic increases, increase in the time point of the estimation of line state error with the line status of the time point that sends with the modulation parameter based on the feedback information decision, its result reduces thereby receiving feature worsens throughput.Be to reduce the deterioration of receiving feature, make the cycle of feedback CSI more little when must be in the time fluctuation amount of transmission path characteristic big more (, notify CSI continually).So the translational speed of travelling carriage is fast more, the transmission quantity of feedback information is big more.

Therefore, technology as the transmission quantity that is used to suppress feedback information, following technology is arranged, promptly, to be defined as low speed (for example 3km/h) to the translational speed of the travelling carriage of each subcarrier (frequency range) control modulation parameter,, switch to the common control of whole subcarriers for the travelling carriage that moves with this speed more than low speed, rather than to the control (for example, with reference to non-patent literature 1) of each subcarrier (frequency range).

And, also have following technology, that is, the travelling carriage that moves with the speed that is lower than maximum translational speed sends CSI, the data volume (for example, with reference to non-patent literature 2 and 3) of cutting down feedback information by the cycle with the integral multiple in minimum feedback cycle.In addition, in non-patent literature 2 and 3, always comprise the CSI of all subcarriers (frequency range) at the feedback information of each timed sending.

[non-patent literature 1] Brian Classon, Philippe Sartori, Vijay Nangia, XiangyangZhuang, Kevin Baum, " Multi-dimensional Adaptation and Multi-userScheduling Techniques for Wireless OFDM Systems ", IEEE InternationalConference on Communications 2003 (ICC2003), Volume3, pp.2251-pp.2255,11-15 May, 2003

[non-patent literature 2] former good filial piety, river end filial piety history, section Jin pine, Seki mouth Gao Zhi " cycle ス ケ ジ ユ one リ Application グ The い MC-CDMA mode ", RCS2002-129, Electricity feelings Reported Communications Society, in July, 2002

[non-patent literature 3] " 3GPP TSGRAN High Speed Downlink Packet Access; Physical Layer Aspects (Release 5) ", 3GPP TR25.858 v5.0.0, March 2002.

Summary of the invention

Problem to be addressed by invention

Yet, in above-mentioned technology in the past, to be cut down though compare the data volume of CSI of the travelling carriage feedback of low speed with maximum translational speed, the data volume of the CSI of the travelling carriage feedback that moves with maximum translational speed still so and is not cut down.Therefore, exist under the big situations such as travelling carriage of a plurality of translational speeds, the data volume of the CSI of feedback increases.

The object of the present invention is to provide and a kind ofly can when keeping high-throughput, cut down the radio communication device and the wireless communications method of the data volume of feedback information.

Be used to solve the means of described problem

The structure that radio communication device of the present invention adopts comprises: receiving element receives the multi-carrier signal that consists of a plurality of subcarriers; Determination unit is measured each subcarrier of described multi-carrier signal or the quality level of each frequency range; Comparing unit compares the variation and the threshold value of described quality level or described quality level; And transmitting element, send described quality level with first feedback cycle and be lower than a part of subcarrier of described threshold value or a part of frequency range or described variation and surpass a part of subcarrier of described threshold value or the CSI or the modulation parameter of a part of frequency range, and send the CSI or the modulation parameter of all subcarriers or all frequency range with second feedback cycle greater than described first feedback cycle.

The beneficial effect of the invention

According to the present invention, can when keeping high-throughput, cut down the data volume of feedback information.

Description of drawings

Fig. 1 is the block diagram of the radio communication device (CSI receiving system) of expression embodiment of the present invention 1.

Fig. 2 is the block diagram of the radio communication device (CSI dispensing device) of expression embodiment of the present invention 1.

Fig. 3 is the block diagram of the CSI processing unit of expression embodiment of the present invention 1.

Fig. 4 is the block diagram of the instantaneous fluctuation measurement unit of expression embodiment of the present invention 1.

Fig. 5 is the carrier structure of the OFDM code element of embodiment of the present invention 1.

Fig. 6 is the SNR variation of expression embodiment of the present invention 1 and the figure of the relation between the threshold value.

Fig. 7 is the figure of the comparative result of expression embodiment of the present invention 1.

Fig. 8 is the figure of action of the radio communication device (CSI dispensing device) of expression embodiment of the present invention 1.

Fig. 9 is the frame format of embodiment of the present invention 1.

Figure 10 is the frame format of embodiment of the present invention 1.

Figure 11 is the frame format of embodiment of the present invention 1.

Figure 12 is the block diagram of the CSI processing unit of expression embodiment of the present invention 1.

Figure 13 is the figure of action of the radio communication device (CSI receiving system) of expression embodiment of the present invention 1.

Figure 14 is the figure of state of the line status memory of expression embodiment of the present invention 1.

Figure 15 is the figure of action of the radio communication device (CSI dispensing device) of expression embodiment of the present invention 2.

Figure 16 is the frame format of embodiment of the present invention 2.

Figure 17 is the frame format of embodiment of the present invention 2.

Figure 18 is the frame format of embodiment of the present invention 2.

Figure 19 is the block diagram of the CSI processing unit of expression embodiment of the present invention 2.

Figure 20 is the figure of action of the radio communication device (CSI receiving system) of expression embodiment of the present invention 2.

Figure 21 is the figure of normalization cumulative distribution of the SNR of expression embodiment of the present invention 3.

Figure 22 is the SNR of expression embodiment of the present invention 3 and the figure of the relation between the threshold value.

Figure 23 is the block diagram of the CSI processing unit of expression embodiment of the present invention 3.

Figure 24 is the block diagram of the threshold calculations unit of expression embodiment of the present invention 3.

Figure 25 is the action flow chart of the radio communication device (CSI dispensing device) of expression embodiment of the present invention 3.

Figure 26 is the block diagram of the CSI processing unit of expression embodiment of the present invention 3.

Figure 27 is the action flow chart of the radio communication device (CSI receiving system) of expression embodiment of the present invention 3.

Figure 28 is the figure of distribution of occurrence number of the SNR of expression embodiment of the present invention 3.

Figure 29 is the block diagram of the CSI processing unit of expression embodiment of the present invention 4.

Figure 30 is the SNR of expression embodiment of the present invention 4 and the figure of the relation between the classification.

Figure 31 is the figure of the classification results of expression embodiment of the present invention 4.

Figure 32 is the figure of action of the radio communication device (CSI dispensing device) of expression embodiment of the present invention 4.

Figure 33 is the frame format of embodiment of the present invention 4.

Figure 34 is the block diagram of the CSI processing unit of expression embodiment of the present invention 4.

Figure 35 is the figure of action of the radio communication device (CSI receiving system) of expression embodiment of the present invention 4.

Figure 36 is the figure of state of the line status memory of expression embodiment of the present invention 4.

Figure 37 is the figure of state of the line status memory of expression embodiment of the present invention 4.

Figure 38 is the frame format of embodiment of the present invention 5.

Figure 39 is the frame format of embodiment of the present invention 5.

Figure 40 is the figure of action of the radio communication device (CSI dispensing device) of expression embodiment of the present invention 5.

Figure 41 is the block diagram of the CSI processing unit of expression embodiment of the present invention 6.

Figure 42 is the SNR of expression embodiment of the present invention 6 and the figure of the relation between the classification.

Figure 43 is the figure of the classification results of expression embodiment of the present invention 6.

Figure 44 is the figure of action of the radio communication device (CSI dispensing device) of expression embodiment of the present invention 6.

Figure 45 is the block diagram of the CSI processing unit of expression embodiment of the present invention 6.

Figure 46 is the figure of action of the radio communication device (CSI receiving system) of expression embodiment of the present invention 6.

Figure 47 is the block diagram of the CSI processing unit of expression embodiment of the present invention 7.

Figure 48 is the MCS conversion example of embodiment of the present invention 7.

Figure 49 is the MCS conversion example of embodiment of the present invention 7.

Figure 50 is the block diagram of the threshold calculations unit of expression embodiment of the present invention 7.

Figure 51 is the block diagram of the radio communication device (CSI dispensing device) of expression embodiment of the present invention 8.

Figure 52 is the mensuration example of the time fluctuation amount of embodiment of the present invention 8 transmission paths response.

Figure 53 is the mensuration example of the time fluctuation amount of embodiment of the present invention 8 transmission paths response.

Figure 54 is the block diagram of the SNR computing unit of expression embodiment of the present invention 8.

Figure 55 is the control example of embodiment of the present invention 8.

Figure 56 is the frame format of embodiment of the present invention 8.

Figure 57 is the frame format of embodiment of the present invention 8.

Figure 58 is the block diagram of the CSI processing unit of expression embodiment of the present invention 8.

Embodiment

Below, present invention will be described in detail with reference to the accompanying execution mode.

(execution mode 1)

Radio communication device shown in Figure 1 is the radio communication device of CSI receiving terminal.And radio communication device shown in Figure 2 is the radio communication device of CSI transmitting terminal.In the following description, the radio communication device of CSI receiving terminal is called the CSI receiving system, the radio communication device of CSI transmitting terminal is called the CSI dispensing device.And the CSI receiving system sends to the CSI dispensing device with the modulation parameter (more than any one of coded system, encoding rate, modulation system and transmitted power) based on the CSI decision with the multi-carrier signal that consists of a plurality of subcarriers.On the other hand, the CSI dispensing device receives the multi-carrier signal that sends from the CSI receiving system, generates CSI based on each subcarrier of multi-carrier signal or the transmission path response of each frequency range.And these CSI receiving systems and CSI dispensing device for example are loaded on radio communication base station device and the radio communication terminal device that uses in the mobile communication system.

As shown in Figure 1, the CSI receiving system of present embodiment comprises: coding unit 11, modulating unit 12, power control unit 13, IFFT (inverse fourier transform) unit 14, GI (guard interval) insertion unit 15, transmission wireless processing unit 16, antenna 17, reception wireless processing unit 21, GI remove unit 22, FFT (Fourier) converter unit 23, demodulating unit 24, decoding unit 25, CSI processing unit 26, CSI receives control unit 27 and modulation parameter determines unit 28.

In following explanation, the CSI receiving system of based on the CSI that receives each subcarrier or each frequency range being set best modulation parameter and sending multi-carrier signal is described.Each group when in addition, so-called frequency range is meant a plurality of subcarriers are divided into a plurality of groups.

The seasonal effect in time series that coding unit 11 is imported each subcarrier (frequency range) coding with the coded system and the encoding rate of modulation parameter decision unit 28 indications sends data.

Modulating unit 12 is with modulation system (M-PSK, M-QAM etc.) the transmission data that modulation has been encoded to each subcarrier (frequency range) of modulation parameter decision unit 28 indications.

Power control unit 13 is the transmission power value of modulation parameter decision unit 28 indications with the transmission power determining of each subcarrier (frequency range).

IFFT unit 14 uses the subcarrier of a plurality of quadratures that the signal by each subcarrier (frequency range) modulation is carried out multiplexing IFFT and handles, and generates the OFDM code element as multi-carrier signal.

GI inserts unit 15 for reducing because of postponing the intersymbol interference (ISI:Inter SymbolInterference) that ripple causes, and inserts GI between the OFDM code element.

Send the wireless processing that 16 pairs of OFDM code elements of wireless processing unit impose regulations such as up-conversion, the OFDM code element after the wireless processing is sent to the CSI dispensing device from antenna 17.

Receive 21 pairs of OFDM code elements that receive with antenna 17 of wireless processing unit and carry out the wireless processing of regulations such as down-conversion.The OFDM code element that receives comprises by the CSI of frameization (CSI frame).

GI removes unit 22 and remove the GI that inserts between the OFDM code element.

OFDM code element after the 23 couples of GI in FFT unit remove is carried out the FFT processing, obtains the signal of each subcarrier.

Signal behind the demodulating unit 24 demodulation FFT, the signal after the decoding unit 25 decoding demodulation.Obtain to receive data thus.Receive in the data and comprise Frame and CSI frame.

CSI processing unit 26 obtains the CSI of each subcarrier (frequency range) from the CSI frame.Classification or processing timing about CSI frame to be processed then receive the control of control unit 27 according to CSI.The detailed description of CSI processing unit 26 is with aftermentioned.

CSI receives control unit 27 and generates the processing of CSI frame and needed control information of renewal and the timing signal of CSI, and control CSI processing unit 26.

Modulation parameter decision unit 28 determines encoding rate, modulation system and the transmitted power of each subcarrier (frequency range) based on the CSI of each subcarrier (frequency range) of importing from CSI processing unit 26.

Next, the CSI dispensing device is described.As shown in Figure 2, the CSI dispensing device of present embodiment comprises: antenna 31, reception wireless processing unit 32, GI remove unit 33, FFT unit 34, demodulating unit 35, decoding unit 36, transmission path response estimation unit 37, CSI processing unit 38, CSI sending controling unit 39, coding unit 41, modulating unit 42, power control unit 43, IFFT unit 44, GI insertion unit 45 and send wireless processing unit 46.

The OFDM code element that receives 31 receptions of 32 pairs of antennas of wireless processing unit is carried out the wireless processing of regulations such as down-conversion.

GI removes unit 33 and remove the GI that inserts between the OFDM code element.

OFDM code element after the 34 couples of GI in FFT unit remove is carried out the FFT processing, obtains the signal of each subcarrier.

Information signal after pilot signal in the signal behind the FFT etc. removed is imported into demodulating unit 35.Demodulating unit 35 is with the demodulation mode demodulating information signal corresponding with the modulation system that is used to modulate at the CSI receiving system.

Decoding unit 36 obtains to receive data after carrying out decoding processing such as error correction with the signal of the decoding process corresponding with the coded system that is used to encode at the CSI receiving system after to modulation.

Needed signal was input to transmission path response estimation unit 37 when the transmission path estimations such as pilot signal in the signal behind the FFT were responded.Transmission path response estimation unit 37 is estimated the transmission path response of each subcarrier (frequency range).

CSI processing unit 38 is obtained the CSI of each subcarrier (frequency range) based on the transmission path response that estimates, and generates the CSI frame that is used for these CSI are fed back to the CSI receiving system.About the classification of the CSI frame that will generate or generate regularly, then according to the control of CSI sending controling unit 39.The detailed description of CSI processing unit 38 is with aftermentioned.

CSI sending controling unit 39 is created on the needed control information of generation and the timing signal of CSI frame, and control CSI processing unit 38.

The seasonal effect in time series that coding unit 41 is imported each subcarrier (frequency range) coding with the coded system and the encoding rate of regulation sends data and CSI frame.

Modulating unit 42 is with modulation system modulation has been encoded to each subcarrier (frequency range) the transmission data and the CSI frame of regulation.

Power control unit 43 is controlled the transmitted power of each subcarrier (frequency range).

IFFT unit 44 uses the subcarrier of a plurality of quadratures that the signal by each subcarrier (frequency range) modulation is carried out multiplexing IFFT and handles, and generates the OFDM code element as multi-carrier signal.

GI inserts unit 45 and postpones the ISI that ripple causes for reducing, and inserts GI between the OFDM code element.

Send the wireless processing that 46 pairs of OFDM code elements of wireless processing unit impose regulations such as up-conversion, the OFDM code element after the wireless processing is sent to the CSI receiving system from antenna 31.

Then, use Fig. 3 to describe the CSI processing unit 38 of the CSI dispensing device shown in Fig. 2 in detail.As shown in Figure 3, CSI processing unit 38 comprises: quality level determination unit 381, line status memory 382, instantaneous fluctuation measurement unit 383, comparing unit 384, comparative result memory 385 and CSI frame generation unit 386.

The transmission path response of each subcarrier that quality level determination unit 381 is imported from transmission path response estimation unit 37 is measured the SNR (Signal to Noise Ratio) of each subcarrier (frequency range), as the value of expression line status.Though use SNR as quality level (quality level) here, also can use CNR (Carrier to Noise Ratio), received power, reception amplitude etc. as quality level.In addition, at the picture cellular system, as CSI, it is not only noise power, in the also considerable communication system of interference power, also can use SIR (Signal to Interference Ratio), CIR (Carrier toInterference Ratio), SINR (Signal to Interference and Noise Ratio), CINR (Carrierto Interference and Noise Ratio) etc. as quality level.

Line status memory 382 keeps the SNR value by each subcarrier (frequency range) of quality level determination unit 381 mensuration.

Instantaneous fluctuation measurement unit 383 is from the instantaneous time fluctuation amount (SNR variation) of the SNR of each subcarrier of SNR pH-value determination pH (frequency range) of line status memory 382 maintenances.The detailed description of instantaneous fluctuation measurement unit 383 is with aftermentioned.

Comparing unit 384 compares the SNR variation and the threshold value of each subcarrier (frequency range).In addition, threshold value is changed adaptively based on average SNR and Doppler frequency.

Comparative result memory 385 is stored the comparative result of comparing unit 384 and is kept by each subcarrier (frequency range).The memory contents of comparative result memory 385 is updated according to the renewal timing signal from 39 inputs of CSI sending controling unit.

CSI frame generation unit 386 generates the CSI frame based on CSI frame category and the generation timing signal from 39 inputs of CSI sending controling unit.CSI frame generation unit 386 is generating the timing that timing signal is transfused to, and generates the CSI frame based on the memory contents of CSI frame category and comparative result memory 385.

Then, use Fig. 4 to describe the instantaneous fluctuation measurement unit 383 shown in Fig. 3 in detail.As shown in Figure 4, instantaneous fluctuation measurement unit 383 comprises delay cell 3831, subtrator 3832 and signed magnitude arithmetic(al) unit 3833.

Delay cell 3831 remains to till the next SNR value input by the SNR value with each subcarrier (frequency range), makes thus from the SNR value of subtrator 3832 inputs to postpone.

Subtrator 3832 calculates by SNR value of each subcarrier (frequency range) of line status memory 382 inputs and poor in the SNR value of previous each subcarriers (frequency range) of delay cell 3831 maintenances.

Signed magnitude arithmetic(al) unit 3833 calculates from the absolute value of the difference of subtrator 3832 inputs, and obtains the variation of SNR.

Below, will further describe the action of CSI processing unit 38 shown in Figure 3.Yet, the situation that each subcarrier is obtained CSI will be described here.And, in following explanation, though be to be that object describes,, can implement present embodiment too to the communication system of each frequency range setting modulation parameter by " subcarrier " changed into " frequency range " with the communication system of each subcarrier being set modulation parameter.

As shown in Figure 5, in the OFDM code element that the CSI dispensing device receives, insert the transmission path response with the interval of regulation and estimate to use carrier wave between data carrier, this transmission path response estimates to be used for carrier wave the frequency response (transmission path response) of transmission path estimation.At transmission path response estimation unit 37, each subcarrier is used transmission path unit estimation carrier wave, at moment t _kAmplitude change and phase place change that the timing estimation OFDM code element of (k is an integer) is subjected at transmission path.In addition, transmission path estimation for example is known pilot signal etc. with carrier wave.And, in the communication system of carrying out blind estimation (blind estimation), use sometimes data with carrier wave as the transmission path estimation carrier wave.

The transmission path response estimation value that quality level determination unit 381 is imported from transmission path response estimation unit 37 is measured the SNR value γ of each subcarrier _{M, k}, and output to line status memory cell 382.Here, γ _{M, k}Expression to m subcarrier (m=1,2,3 ..., moment t M) _kThe time the SNR value carry out value (unit [dB]) after the logarithmic transformation.

382 storages of line status memory are by the SNR value γ of each subcarrier of quality level determination unit 381 mensuration _{M, k}Be stored in the SNR value γ of line status memory 3 82 _{M, k}When measuring new SNR value by quality level determination unit 381, be updated at every turn.

In addition, to be configured to feedback cycle with CSI identical or less than the feedback cycle of CSI the mensuration cycle of the cycle estimator of transmission path response and SNR.The update cycle of line status memory 382 can be independent of the feedback cycle of CSI.But be carried out control, handle with the renewal of avoiding line status memory 382 takes place in the generation way of CSI frame.

In instantaneous fluctuation measurement unit 383, subtrator 3822 is asked the SNR value γ that is stored in line status memory 382 _{M, k}Be maintained at delay cell 3831 at t _kPrevious timing t _K-aThe SNR value γ that measures _{M, k-1}Between poor, and the absolute value of this difference is asked in signed magnitude arithmetic(al) unit 3833.Thus, can obtain the SNR variation Δ γ of each minute each subcarrier at interval of SNR value _{M, k}Therefore, can be with following formula (1) expression SNR variation Δ γ _{M, k}

Δγ _m，k＝|γ _m，k-γ _m，k-1| ...(1)

Comparing unit 384 is the SNR variation and the threshold value of each subcarrier relatively, and this comparative result is write comparative result memory 385.Compare writing in the following manner than result memory 385.In the following description, be that an example describes with the OFDM code element by the situation that 24 subcarriers (subcarrier 1～24) constitute.

Fig. 6 represents the SNR variation Δ γ of each subcarrier _{M, k}And the relation between the threshold value.Situation at example shown in Figure 6, in comparing unit 384, the result that the SNR variation and the threshold value of each subcarrier compared, the SNR variation of subcarrier (SC) 1～4,10,12～15,20,21,23,24 is judged as below the threshold value, and the SNR variation of subcarrier (SC) 5～9,11,16～19,22 is judged as above threshold value.As shown in Figure 7, comparative result is stored in comparative result memory 385.In Fig. 7, " 1 " expression SNR variation is judged as below the threshold value, and " 0 " expression SNR variation is judged as above threshold value.Compare the renewal of result memory 385 in the timing of upgrading timing signal from 39 inputs of CSI sending controling unit.

CSI frame generation unit 386 is in the timing that generates timing signal from 39 inputs of CSI sending controling unit, based on CSI frame category and the comparative result shown in Figure 7 that is stored in comparative result memory 385 from 39 inputs of CSI sending controling unit, from subcarrier 1～24, select CSI to be fed back to the subcarrier of CSI receiving system, and generate the CSI frame.CSI frame generation unit 386 carries out action shown in Figure 8.In example shown in Figure 8, the CSI dispensing device is based on the comparative result at comparing unit 384, with two kinds of CSI frame period property feed back to the CSI receiving system.In two kinds of CSI frames, one side is for being the CSI frame (CSI1) that the SNR value of the subcarrier (subcarrier 1～4,10,12～15,20,21,23,24) below the threshold value is formed by the SNR variation, and the opposing party is the CSI frame of being made up of above the SNR value of the subcarrier (subcarrier 5～9,11,1 6～19,22) of threshold value the SNR variation (CSI2).In other words, CSI2 does not comprise the SNR value that the SNR variation is the following subcarrier (subcarrier 1～4,10,12～15,20,21,23,24) of threshold value.

In Fig. 8, at first in timing t _3n, generate timing signal to 386 inputs of CSI frame generation unit by CSI sending controling unit 39.Simultaneously, be imported into comparative result memory 385, to upgrade the content of comparative result memory 385 at the comparing unit 384 new comparative results that obtain owing to upgrade timing signal.Now, the content of the comparative result memory 385 after supposing to upgrade is for as shown in Figure 7.And, because to the signal of CSI frame generation unit 386 input expressions " CSI1+CSI2 " as the CSI frame category, CSI frame generation unit 386 generates the CSI frame (CSI1+CSI2) of the SNR value of all subcarriers that comprise subcarrier (SC) 1～24 according to indicated CSI frame category from CSI sending controling unit 39.

Frame format is shown in Fig. 9.This frame format is known at the CSI receiving system.Thus, the CSI dispensing device can be in timing t _3nThe CSI of all subcarriers is fed back to the CSI receiving system.In addition, be used in timing t _3nGeneration comprises the CSI frame of the SNR value of all subcarriers, and is assumed to be the frame format of arranging the SNR value from subcarrier 1 in regular turn, but also can be to generate CSI1 and CSI2 respectively and with the frame format that is bonded to each other.For example, also can be the frame format that disposes the CSI2 that constitutes by subcarrier 5～9,11,16～19,22 in the back of the CSI1 that constitutes by subcarrier 1～4,10,12～15,20,21,23,24.

Then, in timing t _3n+1, with timing t _3nSimilarly, will generate timing signal from CSI sending controling unit 39 and be input to CSI frame generation unit 386, and upgrade timing signal and be imported into comparative result memory 385.Then, the content of the comparative result memory 385 after supposing to upgrade becomes as shown in Figure 7 once more.And, because to the signal of CSI frame generation unit 386 input expressions " CSI2 " as the CSI frame category, CSI frame generation unit 386 generates the CSI frame of being made up of above the SNR value of the subcarrier 5～9,11,16～19,22 of threshold value the SNR variation (CSI2) according to indicated CSI frame category from CSI sending controling unit 39.Thus, the CSI dispensing device can be in timing t _3N+1The CSI that only the SNR variation is surpassed the subcarrier of threshold value feeds back to the CSI receiving system.

Frame format is shown in Figure 10.In the example shown in Figure 10, at the identifier of the first half (201) of frame configuration subcarrier sequence number as subcarrier, in latter half (202), with the subcarrier sequence number of first half accordingly, with the arranged in order SNR value identical with the subcarrier sequence number.In addition, as other frame format, also can get frame format as shown in figure 11.In the example shown in Figure 11, make the subcarrier sequence number respectively and be one group (301～304) corresponding to the SNR value of this subcarrier sequence number, these groups (301～304) are configured in the frame.

Then, in timing t _3n+2Carry out with in timing t _3n+1Identical processing, and in timing t _{3 (n+1)}Carry out with in timing t _3nIdentical processing.Thus, in the example shown in Fig. 8, the transmission cycle (feedback cycle) 102 of CSI1 becomes 3 times of transmission cycle (feedback cycle) 101 of CSI2.Like this, by the transmission cycle that makes CSI1 be the integral multiple in the transmission cycle of CSI2, (at Fig. 8 is timing t when the CSI of all subcarrier of feedback _3n, t _{3 (n+1)}) CSI can be summarized in a frame and send, therefore can share header information etc., its result can reduce the data volume that needs in the transmission of feedback information.

Then, use Figure 12 to describe the CSI processing unit 26 shown in Fig. 1 in detail.As shown in figure 12, CSI processing unit 26 comprises quality level extraction unit 261 and line status memory 262.

Quality level extraction unit 261 is receiving the timing that control unit 27 inputs receive timing signal from CSI, based on the CSI frame category that receives control unit 27 inputs from CSI, the SNR value of extracting each subcarrier from CSI frame (sending to the CSI frame of CSI receiving system from the CSI dispensing device) outputs to line status memory 262 as CSI with the subcarrier sequence number.

Line status memory 262 keeps the SNR value of each subcarrier.At this moment, line status memory 262 upgrades the SNR value of corresponding subcarrier based on the subcarrier sequence number from 261 inputs of quality level extraction unit.

The action shown in Figure 8 of CSI processing unit 26 and CSI frame generation unit 386 is carried out action shown in Figure 13 accordingly.

In Figure 13, at first in timing t _3n, receive timing signal and be imported into quality level extraction unit 261 by CSI reception control unit 27.And, receive control unit 27 to the signal of quality level extraction unit 261 input expressions " CSI1+CSI2 " as the CSI frame category from CSI.Therefore, quality level extraction unit 261 receives CSI frame as shown in Figure 9,, comprises the CSI frame (CSI1+CSI2) of SNR value of all subcarriers of subcarrier 1～24 that is.Then, quality level extraction unit 261 extracts subcarrier 1～24 SNR value separately from the CSI frame, adds corresponding subcarrier sequence number and outputs to line status memory 262.Line status memory 262 upgrades the SNR value of all subcarriers.By this processing, can make in timing t _3nThe content of line status memory 382 of CSI dispensing device and the content synchronization of the line status memory 262 of CSI receiving system.And, by the order of decision in advance between CSI dispensing device and CSI receiving system, the subcarrier sequence number need not be included in the CSI frame and send, also the common identification subcarrier sequence number corresponding by both party with each SNR value in CSI frame configuration SNR value.

Then, in timing t _3n+1, with timing t _3nSimilarly, receive control unit 27 by CSI and receive timing signal to 261 inputs of quality level extraction unit.And, receive control unit 27 to the signal of quality level extraction unit 261 input expressions " CSI2 " as the CSI frame category from CSI.Therefore, quality level extraction unit 261 receives as Figure 10 or CSI frame shown in Figure 11, that is, by the SNR variation above the subcarrier sequence number of the subcarrier 5～9,11,16～19,22 of threshold value and the CSI frame (CSI2) that the SNR value is formed.Then, quality level extraction unit 261 extracts subcarrier 5～9,11,16～19,22 subcarrier sequence number and SNR value separately from CSI2, and outputs to line status memory 262.Line status memory 262 upgrades the SNR value corresponding to the subcarrier sequence number of importing from quality level extraction unit 261.In other words, only upgrade the SNR value of the subcarrier 5～9,11,16～19,22 in the subcarrier 1～24.Its result is in timing t _3n+1Renewal after the state of line status memory 262 become as shown in figure 14.3n, 3n+1 in the parantheses represent to upgrade timing t respectively _3n, t _3n+1By this processing, can make in timing t _3n+1The content of line status memory 382 of CSI dispensing device and the content synchronization of the line status memory 262 of CSI receiving system.

Then, in timing t _3n+2Carry out with in timing t _3n+1Identical processing, and in timing t _{3 (n+1)}Carry out with in timing t _3nIdentical processing.

Thus, according to present embodiment, the a plurality of subcarriers that constitute multi-carrier signal are categorized into big subcarrier of the time fluctuation amount of transmission path characteristic and little subcarrier, and the feedback cycle of CSI that makes the little subcarrier of the time fluctuation amount of transmission path characteristic is greater than the feedback cycle of the CSI of the big subcarrier of the time fluctuation amount of transmission path characteristic.Therefore, according to present embodiment, can be in the feedback cycle of the CSI of the big subcarrier of the time fluctuation amount of keeping transmission path characteristic, the transmission quantity of the CSI of the subcarrier that the time fluctuation amount of reduction transmission path characteristic is little, so can when keeping high throughput of system, cut down the data volume of feedback information.

(execution mode 2)

The CSI dispensing device of present embodiment has the structure identical with execution mode 1, but it is different with execution mode 1 in the following areas, promptly, only in the timing of CSI of all subcarriers of feedback subcarrier 1～24, upgrade timing signal and be imported into comparative result memory 385, other regularly then comparative result be not updated.

Below, the action of the CSI frame generation unit 386 of present embodiment is described.In the present embodiment, the action carried out as shown in figure 15 of CSI frame generation unit 386.

In Figure 15, at first in timing t _3n, generate timing signal to 386 inputs of CSI frame generation unit by CSI sending controling unit 39.Simultaneously, be imported into comparative result memory 385, to upgrade the content of comparative result memory 385 at the comparing unit 384 new comparative results that obtain owing to upgrade timing signal.Now, the content of the comparative result memory 385 after supposing to upgrade is for as shown in Figure 7.And, because to the signal of CSI frame generation unit 386 input expressions " CSI1+CSI2 " as the CSI frame category, CSI frame generation unit 386 generates the comparative result of all subcarriers that comprise subcarrier (SC) 1～24 and the CSI frame (CSI1+CSI2) of SNR value according to indicated CSI frame category from CSI sending controling unit 39.

Frame format is shown in Figure 16 and Figure 17.In other words, the comparative result of each subcarrier is sent out as CSI.In addition, this frame format is known at the CSI receiving system.In the example shown in Figure 16,,, dispose the SNR value of each subcarrier in the mode corresponding with the comparative result of first half in latter half (402) at the first half (401) of frame comparative result with the ascending order configuration subcarrier 1～24 of subcarrier sequence number.And in the example shown in Figure 17, making the comparative result of each subcarrier and SNR value respectively is one group (501～503), disposes these groups (501～503) with the ascending order of subcarrier sequence number.In addition, no matter be in the frame format shown in Figure 16 or Figure 17, comparative result becomes the data of 1 bit of " 0 " or " 1 " respectively.

Then, in timing t _3n+1, with timing t _3nSimilarly, generate timing signal and be imported into CSI frame generation unit 386 by CSI sending controling unit 39.But, not being transfused to owing to upgrade timing signal, comparative result memory 385 is not updated.Therefore, the content of comparative result memory 385 is still for as shown in Figure 7.And, because to the signal of CSI frame generation unit 386 input expressions " CSI2 " as the CSI frame category, CSI frame generation unit 386 generates the CSI frame of being made up of above the SNR value of the subcarrier 5～9,11,16～19,22 of threshold value the SNR variation (CSI2) according to indicated CSI frame category from CSI sending controling unit 39.Thus, the CSI dispensing device can be in timing t _3n+1The CSI that only the SNR variation is surpassed the subcarrier of threshold value feeds back to the CSI receiving system.

Frame format is shown in Figure 18.In example shown in Figure 180, the SNR value of subcarrier 5～9,11,16～19,22 is arranged according to the ascending order of subcarrier sequence number.But do not comprise the subcarrier sequence number.Like this, by decision in advance between CSI dispensing device and CSI receiving system the SNR value is arranged according to the ascending order (or descending) of subcarrier sequence number, the subcarrier sequence number need not be included in the CSI frame and send, also the common identification subcarrier sequence number corresponding by both party with each SNR value.Therefore, eliminated that the subcarrier sequence number is included in necessity that the CSI frame sends, thereby can suppress the data volume of CSI2.

Then, in timing t _3n+2Carry out with in timing t _3n+1Identical processing, and in timing t _{3 (n+1)}Carry out with in timing t _3nIdentical processing.

Next, use Figure 19 to describe the structure of the CSI processing unit 26 of present embodiment in detail.As shown in figure 19, the CSI processing unit 26 of present embodiment is further to comprise comparative result memory 263 and constitute in the CSI of execution mode 1 processing unit 26 (Figure 12).

Quality level extraction unit 261 is receiving the timing that control unit 27 inputs receive timing signal from CSI, based on the CSI frame category that receives control unit 27 inputs by CSI, the SNR value of extracting each subcarrier from the CSI frame that is received by the CSI dispensing device outputs to line status memory 262 as CSI with the subcarrier sequence number.And quality level extraction unit 261 extracts the comparative result of each subcarrier from the CSI frame, outputs to comparative result memory 263.

Comparative result memory 263 keeps from the comparative result of quality level extraction unit 261 inputs, when receiving control unit 27 input renewal timing signals from CSI, upgrades the comparative result that keeps with the comparative result that extracts from new CSI frame.

The action shown in Figure 15 of CSI processing unit 26 shown in Figure 19 and CSI frame generation unit 386 is carried out action shown in Figure 20 accordingly.

In Figure 20, at first in timing t _3n, receive control unit 27 by CSI and receive timing signal to 261 inputs of quality level extraction unit.And, receive control unit 27 to the signal of quality level extraction unit 261 input expressions " CSI1+CSI2 " as the CSI frame category from CSI.Therefore, quality level extraction unit 261 receives as Figure 16 or CSI frame shown in Figure 17,, comprises the comparative result of all subcarriers of subcarrier 1～24 and the CSI frame (CSI1+CSI2) of SNR value that is.Then, quality level extraction unit 261 extracts subcarrier 1～24 comparative result and SNR value separately from the CSI frame, and comparative result is outputed to comparative result memory 263, adds the subcarrier sequence number in the SNR value simultaneously and outputs to line status memory 262.Line status memory 262 upgrades the SNR value of all subcarriers.

In addition, in timing t _3n, be imported into comparative result memory 263 owing to upgrade timing signal, so comparative result memory 263 is with in timing t _3nThe comparative result that extracts upgrades the comparative result that is kept.By this processing, can make in timing t _3nThe content of comparative result memory 385 of CSI dispensing device and the content synchronization of the comparative result memory 263 of CSI receiving system.

Then, in timing t _3n+1, with timing t _3nSimilarly, receive control unit 27 by CSI and receive timing signal to 261 inputs of quality level extraction unit.And, receive control unit 27 to the signal of quality level extraction unit 261 input expressions " CSI2 " as the CSI frame category from CSI.But, upgrade timing signal and be not imported into comparative result memory 263.Therefore, in timing t _3n+1, comparative result memory 263 is not updated.

The CSI frame that quality level extraction unit 261 receives as shown in figure 18 promptly, is accepted the CSI frame of only being made up of above the SNR value (that is, comparative result is the SNR value of " 0 ") of the subcarrier 5～9,11,16～19,22 of threshold value the SNR variation (CSI2).Then, quality level extraction unit 261 extracts subcarrier 5～9,11,16～19,22 SNR value separately from CSI2, and with reference to comparative result memory 263, obtaining comparative result from comparative result memory 263 is the subcarrier sequence number of the subcarrier of " 0 ".Then, quality level extraction unit 261 adds corresponding subcarrier sequence number respectively and outputs to line status memory 262 in the SNR value that extracts.

As above-mentioned, because the configuration sequence of the SNR value of CSI2 is set at the ascending order (or descending) of subcarrier sequence number in advance, even in CSI2, do not comprise the subcarrier sequence number, quality level extraction unit 261 can identify the SNR value of each SNR value for which subcarrier by with reference to comparative result memory 263.And, owing to necessity of having eliminated by CSI2 transmitting subcarrier sequence number, so can cut down the data volume of feedback information.

Line status memory 262 upgrades the SNR value corresponding to the subcarrier sequence number of importing from quality level extraction unit 261.In other words, only upgrade the SNR value of the subcarrier 5～9,11,16～19,22 in the subcarrier 1～24.Its result is in timing t _3n+1Renewal after the state of line status memory 262 become as shown in figure 14.By this processing, can make in timing t _3n+1The content of line status memory 382 of CSI dispensing device and the content synchronization of the line status memory 262 of CSI receiving system.

Then, in timing t _3n+2Carry out with in timing t _3n+1Identical processing, and in timing t _{3 (n+1)}Carry out with in timing t _3nIdentical processing.

Thus, according to present embodiment, by comparative result with 1 each subcarrier of bit transfer, can share comparative result by CSI dispensing device and CSI receiving system, needn't in CSI2, transmit the subcarrier sequence number of each SNR value, compare with execution mode 1, can cut down the data volume of feedback information further.Therefore, execution mode 2 is effective more more for a long time in the number of sub that is contained in the 1OFDM code element (or frequency range number).

(execution mode 3)

Multi-path environment mostly is NLOS (the Non lineof sight) environment that has barrier between sending station and receiving platform greatly, and known each delay ripple can produce Rayleigh change (Rayleigh variation).And when the time of delay of delay ripple and symbol time were big by contrast, its characteristic had frequency selectivity.Be illustrated in below in such frequency selectivity Rayleigh fading transmission path, to the cumulative distribution of the SNR of each subcarrier.

Figure 21 is illustrated under the situation of average SNR=30dB in the frequency selectivity Rayleigh fading transmission path, with the figure of the cumulative distribution after the SNR normalization of each subcarrier.The 601st, the normalization cumulative distribution of the SNR of all subcarriers, the 602nd, the variation of time per unit is lower than the normalization cumulative distribution of SNR of the subcarrier of 1dB, and the 603rd, the variation of time per unit is the normalization cumulative distribution of the SNR of the above subcarrier of 1dB.

According to Figure 21, in the zone that the SNR of this subcarrier value distributes, the variation of the SNR value of time per unit is the zone of the above subcarrier distribution of 1dB in less SNR value as can be known.On the other hand, in the zone that the SNR of this subcarrier value distributes, the variation of the SNR value of time per unit is lower than the zone of the subcarrier distribution of 1dB in bigger SNR value.Therefore, by based on going up average SNR value (average SNR) and setting threshold at all subcarriers (at frequency domain), with the SNR value of each subcarrier and this threshold ratio, can be divided into the big sub carrier groups of variation of the SNR value of time per unit, and the little sub carrier groups of variation of the SNR value of time per unit.

Therefore, in the present embodiment, as shown in figure 22, relatively, a plurality of subcarriers (is subcarrier 1～24 at this) that constitute the OFDM code element are divided into big subcarrier of SNR variation and the little subcarrier of SNR variation based on the SNR value of average SNR preset threshold and each subcarrier.

Use Figure 23 to describe the structure of the CSI processing unit 38 of present embodiment in detail below.As shown in figure 23, the CSI processing unit 38 of present embodiment is compared with the CSI processing unit 38 (Fig. 3) of execution mode 1, and its structure further comprises threshold calculations unit 387 and reduced instantaneous fluctuation measurement unit 383.

Threshold calculations unit 387 on average is stored in the SNR value of each subcarrier in the line status memory 382 to obtain average SNR on all subcarriers, use average SNR to set the threshold value of comparing unit 384.The detailed description of threshold calculations unit 387 is with aftermentioned.

384 pairs of threshold values that calculate in threshold calculations unit 387 of comparing unit compare with the SNR value that is stored in each subcarrier of line status memory 382.

Comparative result memory 385 is stored the comparative result of comparing unit 384 and is kept by each subcarrier.The memory contents of comparative result memory 385 is updated according to the renewal timing signal from 39 inputs of CSI sending controling unit.

Then, use Figure 24 to describe the threshold calculations unit 387 shown in Figure 23 in detail.As shown in figure 24, threshold calculations unit 387 comprises: unit 3875 is given in logarithm/linear transform unit 3871, frequency averaging unit 3872, termporal filter unit 3873, linearity/logarithmic transformation unit 3874 and skew.

Logarithm/linearity (Log-Linear) converter unit 3871 will be from the SNR value γ of each subcarrier of line status memory 382 input _{M, k}From the dB value transform is the SNR value Γ of true value _{M, k}And,, just do not need this logarithm/linear transform unit 3871 if the SNR value of each subcarrier of input is exactly a true value originally.

Frequency averaging unit 3872 is based on following formula (2), at SNR value (true value) Γ of all subcarrier 1～24 average each subcarriers _{M, k}, the mean value (average SNR) of the SNR of calculating frequency domain.In this example, though be the mean value of asking SNR, also can be in the hope of median.

${\stackrel{\‾}{\mathrm{\Γ}}}_k=\frac{1}{N}\underset{m=0}{\overset{M-1}{\mathrm{\Σ}}}{\mathrm{\Γ}}_{m,k}\·\·\·\left(2\right)$

: the mean value of SNR (true value)

The 3873 pairs of average SNR in termporal filter unit (true value) are carried out the filtering (time filtering) of time orientation.By average SNR is carried out time filtering, can obtain not follow the tracks of the instantaneous change of transmission path, but follow the tracks of the average SNR of short interval change (shielding change (shadowing variation)).And the time constant that can obtain such average SNR is set in termporal filter unit 3873.Therefore, can obtain in whole communication band also can directly use mean value or the median of the SNR that obtains at frequency domain, and not carry out time filtering under the transmission path situation of sufficient frequency selectivity.In addition,, also can carry out rolling average and handle, perhaps utilize FIR filter or iir filter the average SNR (true value) of all subcarriers in past as time filtering.In addition, filter time constant is set for the speed that changes (shielding change) less than short interval.In addition, in the most easy structure, for example also can constitute termporal filter unit 3873 based on following formula (3).

${\widehat{\mathrm{\Γ}}}_k=\mathrm{\μ}\·{\stackrel{\‾}{\mathrm{\Γ}}}_k+(1-\mathrm{\μ}){\widehat{\mathrm{\Γ}}}_{k-1},0\≤\mathrm{\μ}\≤1\·\·\·\left(3\right)$

: carry out the average SNR value (true value) after the time filtering

Linearity/logarithm (Linear-Log) converter unit 3874 is transformed to the average SNR value (true value) of elapsed time filtering the average SNR value of dB value.

Skew is given the average SNR value of the 3875 pairs of dB values in unit and is given deviant.Thus, calculate the threshold value of using at comparing unit 384.Therefore, threshold value is represented by following formula (4).In addition, threshold calculations unit 387 also can adopt the structure that does not comprise that unit 387 is given in skew.

${\mathrm{\γ}}_{\mathrm{threshold}={\stackrel{\‾}{\mathrm{\γ}}}_k+\mathrm{\α}\left[\mathrm{dB}\right]\·\·\·\left(4\right)}$

γ _Threshold: threshold value

: carry out the average SNR value (dB value) after the time filtering

α: deviant

Then, comparing unit 384 is the SNR value and the threshold value of each subcarrier relatively, and this comparative result is write comparative result memory 385.Compare writing in the following manner than result memory 385.

Situation at example shown in Figure 22, in comparing unit 384, the result that the SNR value and the threshold value of each subcarrier compared, subcarrier l～4,10,12～15,20,21,23,24 SNR value are judged as more than the threshold value, and the SNR value of subcarrier 5～9,11,16～19,22 is judged as and is lower than threshold value.As shown in Figure 7, comparative result is stored in comparative result memory 385.In present embodiment, in Fig. 7, " 1 " expression SNR value is judged as more than the threshold value, and " 0 " expression SNR value is judged as and is lower than threshold value.Compare the renewal of result memory 385 in the timing of upgrading timing signal from 39 inputs of CSI sending controling unit.

CSI frame generation unit 386 is in the timing that generates timing signal from 39 inputs of CSI sending controling unit, based on CSI frame category and the comparative result shown in Figure 7 that is stored in comparative result memory 385 from 39 inputs of CSI sending controling unit, from subcarrier 1～24, select CSI to be fed back to the subcarrier of CSI receiving system, and generate the CSI frame.The action that CSI frame generation unit 386 carries out as shown in figure 15.

In other words, at first in timing t _3n, generate timing signal to 386 inputs of CSI frame generation unit by CSI sending controling unit 39.Simultaneously, be imported into comparative result memory 385, to upgrade the content of comparative result memory 385 at the comparing unit 384 new comparative results that obtain owing to upgrade timing signal.And be in timing t in the threshold value that comparing unit 384 uses this moment _3nThe threshold value that newly calculates by threshold calculations unit 387.Now, the content of the comparative result memory 385 after supposing to upgrade is for as shown in Figure 7.And, because to the signal of CSI frame generation unit 386 input expressions " CSI1+CSI2 " as the CSI frame category, CSI frame generation unit 386 generates the CSI frame (CSI1+CSI2) of the SNR value of all subcarriers that comprised subcarrier 1～24 according to indicated CSI frame category from CSI sending controling unit 39.Frame format is shown in Figure 9.

Then, in timing t _3n+1, with timing t _3nSimilarly, generate timing signal by CSI sending controling unit 39 to 386 inputs of CSI frame generation unit.But, not being transfused to owing to upgrade timing signal, comparative result memory 385 is not updated.Therefore, the content of comparative result memory 385 is still for as shown in Figure 7.And, do not calculate new threshold value yet.And, because to CSI frame generation unit 386 input expression " CSI2 " signal as the CSI frame category, CSI frame generation unit 386 generates by the SNR value according to indicated CSI frame category and is lower than the CSI frame (CSI2) that the SNR value of the subcarrier 5～9,11,16～19,22 of threshold value is formed from CSI sending controling unit 39.Thus, the CSI dispensing device can be in timing t _3n+1The CSI that only the SNR value is lower than the subcarrier of threshold value feeds back to the CSI receiving system.Frame format is shown in Figure 180.

Then, in timing t _3n+2Carry out with in timing t _3n+1Identical processing, and in timing t _{3 (n+1)}Carry out with in timing t _3nIdentical processing.

When above action schedule is shown flow chart for as shown in figure 25.In other words, judged whether to generate the timing signal input, when the generation timing signal is transfused to (ST701: be), judged whether to upgrade the timing signal input at ST702 at ST (step) 701.Then, when upgrading timing signal and be transfused to (ST702: be), advance to ST704 after upgrading the comparative result memory, (ST702: not), do not upgrade the comparative result memory and advance to ST704 when not upgrading the timing signal input.Judge the CSI frame category at ST704.In other words, when expression " CSI1+CSI2 " is imported as the signal of CSI frame category, generate the CSI frame (CSI1+CSI2) of the SNR value of all subcarriers that comprise subcarrier 1～24 at ST705.On the other hand, expression " CSI2 " is during as the input of the signal of CSI frame category, generates by the SNR value at ST706 to be lower than the CSI frame (CSI2) that the SNR value of the subcarrier 5～9,11,16～19,22 of threshold value is formed.

Next, use Figure 26 to describe the structure of the CSI processing unit 26 of present embodiment in detail.As shown in figure 26, the CSI processing unit 26 of present embodiment is further to comprise threshold calculations unit 264 and comparing unit 265 and constitute at the CSI of execution mode 2 processing unit 26 (Figure 19).Threshold calculations unit 264 and comparing unit 265 adopts the structure (Figure 23 and Figure 24) identical with the threshold calculations unit 387 of CSI dispensing device and comparing unit 384, and it moves its explanation of Therefore, omited also same as described above.

CSI processing unit 26 shown in Figure 26 carries out action shown in Figure 20 corresponding to the action of CSI frame generation unit 386 shown in Figure 23.

In other words, at first in timing t _3n, receive timing signal and be imported into quality level extraction unit 261 from CSI reception control unit 27.And, represent that as the CSI frame category signal of " CSI1+CSI2 " is imported into quality level extraction unit 261 from CSI reception control unit 27.Therefore, quality level extraction unit 261 receives CSI frame as shown in Figure 9,, comprises the CSI frame (CSI1+CSI2) of SNR value of all subcarriers of subcarrier 1～24 that is.Then, quality level extraction unit 261 extracts subcarrier 1～24 SNR value separately from the CSI frame, adds corresponding subcarrier sequence number and outputs to line status memory 262.Line status memory 262 upgrades the SNR value of all subcarriers.

In addition, in timing t _3n, be imported into comparative result memory 263 owing to upgrade timing signal, comparative result memory 263 with by comparing unit 265 in timing t _3nThe comparative result that extracts upgrades the comparative result that is kept.And be in timing t in the threshold value that comparing unit 265 uses this moment _3nThe threshold value that newly calculates by threshold calculations unit 264.The threshold value calculation method of threshold calculations unit 264 is to use the method identical with the threshold calculations unit 387 of CSI dispensing device.By this processing, can make in timing t _3nThe content of comparative result memory 385 of CSI dispensing device and the content synchronization of the comparative result memory 263 of CSI receiving system.

Then, in timing t _3n+1, with timing t _3nSimilarly, receive timing signal and be imported into quality level extraction unit 261 from CSI reception control unit 27.And, represent that as the CSI frame category signal of " CSI2 " is imported into quality level extraction unit 261 from CSI reception control unit 27.But, upgrade timing signal and be not imported into comparative result memory 263.Therefore, in timing t _3n+1, comparative result memory 263 is not updated, and the state of comparative result memory 263 maintains t _3nState after the renewal.And, do not calculate new threshold value yet.

The CSI frame that quality level extraction unit 261 receives as shown in figure 18 promptly, only is lower than the CSI frame (CSI2) of SNR value (that is, comparative result is the SNR value of " the 0 ") composition of the subcarrier 5～9,11,16～19,22 of threshold value by the SNR value.Then, quality level extraction unit 261 extracts subcarrier 5～9,11,16～19,22 SNR value separately from CSI2, and with reference to comparative result memory 263, obtaining comparative result from comparative result memory 263 is the subcarrier sequence number of the subcarrier of " 0 ".Then, quality level extraction unit 261 adds corresponding subcarrier sequence number respectively and outputs to line status memory 262 in the SNR value that extracts.

In example shown in Figure 180, the SNR value of subcarrier 5～9,11,16～19,22 is arranged according to the ascending order of subcarrier sequence number.But do not comprise the subcarrier sequence number.Like this, by decision in advance between CSI dispensing device and CSI receiving system the SNR value is arranged according to the ascending order (or descending) of subcarrier sequence number, the subcarrier sequence number need not be included in the CSI frame and send, also can be in both sides' common identification subcarrier sequence number corresponding with each SNR value.Therefore, eliminated that the subcarrier sequence number is included in necessity that the CSI frame sends, thereby can suppress the data volume of CSI2.

Line status memory 262 upgrades the SNR value corresponding to the subcarrier sequence number of importing from quality level extraction unit 261.In other words, only upgrade the SNR value of the subcarrier 5～9,11,16～19,22 in the subcarrier 1～24.Its result is in timing t _3n+1Renewal after the state of line status memory 262 become as shown in figure 14.By this processing, can make in timing t _3n+1The content of line status memory 382 of CSI dispensing device and the content synchronization of the line status memory 262 of CSI receiving system.

Then, in timing t _3n+2Carry out with in timing t _3n+1Identical processing, and in timing t _{3 (n+1)}Carry out with in timing t _3nIdentical processing.

Be shown in Figure 27 when above action schedule is shown flow chart.In other words, judged whether to receive the timing signal input, when the reception timing signal is transfused to (ST801: be), judged the CSI frame category at ST802 at ST (step) 801.In other words, when expression " CSI1+CSI2 " is imported as the signal of CSI frame category, upgrade the line status (that is the SNR value of subcarrier 1～24) of all subcarriers at ST803.On the other hand, when expression " CSI2 " is imported as the signal of CSI frame category, upgrade the line status (that is, the SNR value is lower than the SNR value of the subcarrier 5～9,11,16～19,22 of threshold value) of CSI2 at ST804.Next, judged whether to upgrade the timing signal input at ST805.Then, when the input of the timing signal of renewal is arranged (ST805: have), upgrade the comparative result memory.On the other hand, (ST805: not), get back to ST801 and judged whether to receive the timing signal input once more when not upgrading the timing signal input.

Like this, according to present embodiment, even the CSI receiving system also can with CSI dispensing device calculated threshold similarly, and the SNR value of this threshold value that calculates and each subcarrier relatively, therefore eliminated in the necessity that to the CSI frame of CSI receiving system feedback, comprises the comparative result of subcarrier sequence number and each subcarrier from the CSI dispensing device, compare with execution mode 2 with execution mode 1, can further cut down the data volume of feedback information.

Here, as above-mentioned, multi-path environment mostly is NLOS (the Non 1ine of sight) environment that has barrier between dispatching station and receiving platform greatly, and known each delay ripple can produce Rayleigh change (Rayleighvariation).And when the time of delay of delay ripple and symbol time were big by contrast, its characteristic had frequency selectivity.Be illustrated in below in such frequency selectivity Rayleigh fading transmission path, to the block diagram of the variation of the time per unit of the SNR of each subcarrier.

Figure 28 is illustrated under the situation of average SNR=30dB in the frequency selectivity Rayleigh fading transmission path figure of the distribution of the occurrence number of the SNR of each subcarrier.The 701st, the distribution of the occurrence number of the SNR value of all subcarriers, the 702nd, the variation of time per unit is lower than the distribution of occurrence number of SNR value of the subcarrier of 1dB, and the 703rd, the variation of time per unit is the distribution of occurrence number of the SNR value of the above subcarrier of 1dB.

According to Figure 28, in all subcarriers, the variation of the SNR value of time per unit is that the subcarrier that is lower than 1dB accounts for major part.The number of subcarriers that this expression can be got bigger feedback cycle is many, and this effect of data volume of also representing reduction feedback information of the present invention is very big.For example, when comparing, in above-mentioned prior art, cooperate the big subcarrier of time fluctuation amount, all feed back the CSI of all subcarriers at every turn with above-mentioned maximum translational speed of the prior art.Relative therewith, in the present invention, as above-mentioned, the CSI of the subcarrier of feedback time variation big (that is, SNR value is little) only at every turn, the then each feedback of all carrying out CSI of the subcarrier of time fluctuation amount little (that is, SNR value is greatly).Therefore, according to the present invention, can cut down the data volume of feedback information.

(execution mode 4)

Present embodiment is different with execution mode 3 in the following areas,, based on the CSI frame size, a plurality of subcarriers (being subcarrier 1～24 here) that constitute the OFDM code element is divided into a plurality of groups that is.

Now use Figure 29 to describe the structure of the CSI processing unit 38 of present embodiment in detail.As shown in figure 29, the CSI processing unit 38 of present embodiment is compared with the CSI processing unit 38 (Fig. 3) of execution mode 1, its structure further comprises taxon 388 and classification results memory 389, and has reduced instantaneous fluctuation measurement unit 383, comparing unit 384 and comparative result memory 385.

Taxon 388 is categorized as a plurality of groups based on the CSI frame size of CSI frame size information representation with the SNR value that is stored in each subcarrier of line status memory 382.Because at the CSI frame size more hour, the data volume of CSI that can be included in a CSI frame is few more, so taxon 388 is categorized as more group.And taxon 388 is categorized into a plurality of groups according to the big order or the little order of the SNR value of each subcarrier with each subcarrier.The concrete example of classification is with aftermentioned.

Comparative result memory 389 is stored the classification results of taxon 388 and is kept by each subcarrier.The memory contents of classification results memory 389 is updated according to the renewal timing signal from 39 inputs of CSI sending controling unit.

Then, use the concrete example of Figure 30 explanation in the classification of taxon 388.Here, for can sending the size of SNR value of 8 subcarriers, and the situation that subcarrier 1～24 is categorized into three groups describes as an example with the CSI frame size.

When the SNR of each subcarrier 1～24 is situation shown in Figure 30, taxon 388 with subcarrier 1～24 according to the big order of SNR value (that is the little order of the variation of SNR value) classification three groups of 1,2,3 in groups.In addition, taxon 388 also can be with subcarrier 1～24 according to the little order of SNR value (that is the big order of the variation of SNR value) classification three groups of 3,2,1 in groups.Its result, subcarrier 1,3,4,10,12,14,21,23 is classified into group 1, and subcarrier 2,5,6,9,13,15,20,24 is classified into group 2, and subcarrier 7,8,11,16,17,18,19,22 is classified into group 3.As shown in figure 31, this classification results is stored in classification results memory 389.Carry out the renewal of classification results memory 389 in the timing of upgrading timing signal from 39 inputs of CSI sending controling unit.

CSI frame generation unit 386 is in the timing that generates timing signal from 39 inputs of CSI sending controling unit, based on CSI frame category and the classification results shown in Figure 31 that is stored in classification results memory 389 from 39 inputs of CSI sending controling unit, from subcarrier 1～24, select CSI to be fed back to the subcarrier of CSI receiving system, and generate the CSI frame.CSI frame generation unit 386 moves shown in figure 32.In example shown in Figure 32, the CSI dispensing device is based at above-mentioned classification results, with three kinds of CSI frame period property feed back to the CSI receiving system.In three kinds of CSI frames of CSI1～CSI3, the CSI frame that CSI1 is made up of the SNR value of group 1 ( subcarrier 1,3,4,10,12,14,21,23), the CSI frame that CSI2 is made up of the SNR value of group 2 ( subcarriers 2,5,6,9,13,15,20,24), the CSI frame that CSI3 is made up of the SNR value of group 3 ( subcarriers 7,8,11,16,17,18,19,22).

In Figure 32, at first in timing t _4n, generate timing signal and be imported into CSI frame generation unit 386 from CSI sending controling unit 39.Simultaneously, be imported into classification results memory 389, to upgrade the content of classification results memory 389 at the taxon 388 new classification results that obtain owing to upgrade timing signal.Now, the content of the classification results memory 389 after supposing to upgrade is for as shown in figure 31.And, because to the signal of CSI frame generation unit 386 input expressions " CSI1+CSI2+CSI3 " as the CSI frame category, CSI frame generation unit 386 generates the CSI frame (CSI1+CSI2+CSI3) of the SNR value of all subcarriers that comprise subcarrier 1～24 according to indicated CSI frame category from CSI sending controling unit 39.Frame format is shown in Figure 9.

Then, in timing t _4n+1, with timing t _4nSimilarly, generate timing signal and be imported into CSI frame generation unit 386 from CSI sending controling unit 39.But, not being transfused to classification results memory 389 owing to upgrade timing signal, classification results memory 389 is not updated.Therefore, the content of classification results memory 389 is still for as shown in figure 31.And, owing to represent that as the CSI frame category signal of " CSI3 " is imported into CSI frame generation unit 386 from CSI sending controling unit 39, so the CSI frame (CSI3) that CSI frame generation unit 386 is made up of the SNR value of the subcarrier 7,8,11,16,17,18,19,22 of group 3 according to indicated CSI frame category generation.Thus, the CSI dispensing device can be in timing t _4n+1Only the CSI with the subcarrier of the group 3 of SNR value minimum (that is SNR variation maximum) feeds back to the CSI receiving system.And, with Figure 18 similarly, frame format is shown in Figure 33.

Then, in timing t _4n+2, with timing t _4n+1Similarly, will generate timing signal from CSI sending controling unit 39 and be input to CSI frame generation unit 389, be not input to classification results memory 389 but upgrade timing signal, so classification results memory 389 not be updated.Therefore, the content of classification results memory 389 is still for as shown in figure 31.In addition, owing to represent that as the CSI frame category signal of " CSI2+CSI3 " is imported into CSI frame generation unit 386 from CSI sending controling unit 39, so CSI frame generation unit 386 is according to indicated CSI frame category, generate by the SNR value of the subcarrier 2,5,6,9,13,15,20,24 of group 2 and the CSI frame (CSI2+CSI3) formed by the SNR value of organizing 3 subcarrier 7,8,11,16,17,18,19,22.Thus, the CSI dispensing device can be in timing t _4n+2Only will organize 2 and the CSI of group 3 subcarrier feed back to the CSI receiving system.And frame format is identical with Figure 18 and Figure 33.

Then, in timing t _4n+3Carry out with in timing t _4n+1Identical processing, and in timing t _{4 (n+1)}Carry out with in timing t _4nIdentical processing.Thus, in the example shown in Figure 32, the transmission cycle (feedback cycle) 107 of CSI1 becomes 4 times of transmission cycle (feedback cycle) 105 of CSI3, and the transmission cycle (feedback cycle) 106 of CSI2 becomes the twice in the transmission cycle 105 of CSI3.And the transmission cycle 107 of CSI1 becomes the twice in the transmission cycle 106 of CSI2.Like this, by the transmission cycle that makes CSI1 and CSI2 be the integral multiple in the transmission cycle of CSI3, (at Figure 32 is timing t when the CSI of all subcarrier of feedback _4n, t _{4 (n+1)}) CSI can be summarized in a frame and send, therefore can share header information etc., its result can reduce in the needed data volume of the transmission of feedback information.

Next, use Figure 34 to describe the structure of the CSI processing unit 26 of present embodiment in detail.As shown in figure 34, the CSI processing unit 26 of present embodiment is further to comprise taxon 266 and classification results memory 267 and constitute at the CSI of execution mode 1 processing unit 26 (Figure 12).

The action of CSI processing unit 26 shown in Figure 34 and CSI frame generation unit 386 shown in Figure 29 is carried out action shown in Figure 35 accordingly.

In other words, at first in timing t _4n, receive timing signal and be imported into quality level extraction unit 261 from CSI reception control unit 27.And, represent that as the CSI frame category signal of " CSI1+CSI2+CSI3 " is imported into quality level extraction unit 261 from CSI reception control unit 27.Therefore, quality level extraction unit 261 receives CSI frame as shown in Figure 9,, comprises the CSI frame (CSI1+CSI2+CSI3) of SNR value of all subcarriers of subcarrier 1～24 that is.Then, quality level extraction unit 261 extracts subcarrier 1～24 SNR value separately from the CSI frame, adds corresponding subcarrier sequence number and outputs to line status memory 262.Line status memory 262 upgrades the SNR value of all subcarriers.

In addition, in timing t _4n, be imported into classification results memory 267 owing to upgrade timing signal, classification results memory 267 with by taxon 266 in timing t _4nThe classification results that obtains upgrades the classification results that is kept.The sorting technique of taxon 266 is to use the method identical with the taxon 388 of CSI dispensing device.By this processing, can make in timing t _4nThe content of classification results memory 389 of CSI dispensing device and the content synchronization of the classification results memory 267 of CSI receiving system.

Then, in timing t _4n+1, with timing t _4nSimilarly, receive control unit 27 by CSI and receive timing signal to 261 inputs of quality level extraction unit.And, receive control unit 27 to the signal of quality level extraction unit 261 input expressions " CSI3 " as the CSI frame category from CSI.But, upgrade timing signal and be not imported into classification results memory 267.Therefore, in timing t _4n+1, classification results memory 267 is not updated, and the state of classification results memory 267 maintains t _4nState after the renewal.

Quality level extraction unit 261 receives CSI frame as shown in figure 33, that is, and and the CSI frame of forming by the SNR value of the subcarrier 7,8,11,16,17,18,19,22 of group 3 (CSI3) only.Then, quality level extraction unit 261 extracts subcarrier 7,8,11,16,17,18,19,22 SNR value separately from CSI3, and with reference to classification results memory 267, from the subcarrier sequence number of the subcarrier of classification results memory 267 acquisition groups 3.Then, quality level extraction unit 261 adds corresponding subcarrier sequence number respectively and outputs to line status memory 262 in the SNR value that extracts.

In example shown in Figure 33, with the ascending order arrangement of the SNR value of group 3 subcarrier 7,8,11,16,17,18,19,22 according to the subcarrier sequence number.But do not comprise the subcarrier sequence number.Like this, by decision in advance between CSI dispensing device and CSI receiving system the SNR value is arranged according to the ascending order (or descending) of subcarrier sequence number, the subcarrier sequence number need not be included in the CSI frame and send, also can be in both sides' common identification subcarrier sequence number corresponding with each SNR value.Therefore, eliminated that the subcarrier sequence number is included in necessity that the CSI frame sends, thereby can suppress the data volume of CSI3.

Line status memory 262 upgrades the SNR value corresponding to the subcarrier sequence number of importing from quality level extraction unit 261.In other words, only upgrade the SNR value of the subcarrier 7,8,11,16,17,18,19,22 in the subcarrier 1～24.Its result is in timing t _4n+1Renewal after the state of line status memory 262 become as shown in figure 36.By this processing, can make in timing t _4n+1The content of line status memory 382 of CSI dispensing device and the content synchronization of the line status memory 262 of CSI receiving system.

Then, in timing t _4n+2, receive timing signal and be imported into quality level extraction unit 261 from CSI reception control unit 27.And, represent that as the CSI frame category signal of " CSI2+CSI3 " is imported into quality level extraction unit 261 from CSI reception control unit 27.But, upgrade timing signal and be not imported into classification results memory 267.Therefore, in timing t _4n+2, classification results memory 267 is not updated, and the state of classification results memory 267 maintains t _4nState after the renewal.

Quality level extraction unit 261 receives the CSI frame with Figure 33 same number of frames form, that is, by the SNR value of group 2 subcarrier 2,5,6,9,13,15,20,24 and the CSI frame (CSI2+CSI3) formed by the SNR value of organizing 3 subcarrier 7,8,11,16,17,18,19,22.Then, quality level extraction unit 261 extracts subcarrier 2,5,6,9,13,15,20,24 SNR value separately from CSI2, extract subcarrier 7,8,11,16,17,18,19,22 SNR value separately from CSI3 simultaneously, and with reference to classification results memory 267, from the subcarrier sequence number of the classification results memory 267 acquisition groups 2 and the subcarrier of group 3.Then, quality level extraction unit 261 adds corresponding subcarrier sequence number respectively and outputs to line status memory 262 in the SNR value that extracts.

Line status memory 262 upgrades the SNR value corresponding to the subcarrier sequence number of importing from quality level extraction unit 261.That is, in subcarrier 1～24, the SNR value of the subcarrier 2,5,6,9,13,15,20,24 of update group 2 and organize the SNR value of 3 subcarrier 7,8,11,16,17,18,19,22 only.Its result is in timing t _4n+2Renewal after the state of line status memory 262 become as shown in figure 37.By this processing, can make in timing t _4n+2The content of line status memory 382 of CSI dispensing device and the content synchronization of the line status memory 262 of CSI receiving system.

Then, in timing t _4n+3Carry out with in timing t _4n+1Identical processing, and in timing t _{4 (n+1)}Carry out with in timing t _4nIdentical processing.

Like this, according to present embodiment, be categorized into a plurality of groups owing to will constitute a plurality of subcarriers of OFDM code element based on the CSI frame size, be fixing by decision in advance or be restricted in the communication system of several kinds at the CSI frame size, can make the feedback cycle of CSI based on the time fluctuation amount of transmission path characteristic by a plurality of phase change.And, owing to eliminated in the necessity that to the CSI frame of CSI receiving system feedback, comprises the classification results of subcarrier sequence number and subcarrier from the CSI dispensing device, with execution mode 3 similarly, can further cut down the data volume of feedback information.

In addition, in the present embodiment, the SNR value that sends at CSI3 is little SNR value, therefore, feeds back the transfer rate step-down of subcarrier 7,8,11,16,17,18,19,22 of the group 3 of SNR value with CSI3.On the other hand, owing to the variation of the SNR value that sends at CSI3 is big, so CSI3 must feed back with the short cycle.And when the expense of CSI3 becomes big with respect to the transfer rate of feeding back the subcarrier of CSI with CSI3, the transmission that also can omit CSI3.In other words, the SNR value (or variation of SNR value) of a plurality of subcarriers when becoming a plurality of groups according to magnitude classification, also can omitted the feedback of the minimum group (or group of the variation maximum of SNR value) of SNR value.

(execution mode 5)

Present embodiment is different with execution mode 4 in the following areas, promptly, timing at the CSI of all subcarriers of the subcarrier 1～24 that send to constitute the OFDM code element, the difference of the SNR value between the adjacent subcarrier is sent as CSI, in the timing of the CSI that sends a part of subcarrier, will send as CSI in the difference of the SNR value between the inequality timing of same subcarrier.Below, the difference with execution mode 4 only is described.

At first, reuse the action that Figure 32 illustrates the CSI frame generation unit 386 of present embodiment.

In Figure 32, in timing t _4n, CSI frame generation unit 386 generates the CSI frame (CSI1+CSI2+CSI3) of the CSI of all subcarriers that comprised subcarrier 1～24.In timing t _4n, CSI frame generation unit 386 is obtained difference (difference SNR value) the Δ γ of the SNR value between the adjacent sub-carriers from the SNR value of each subcarrier of remaining on line status memory 382 _{M, 4n}, generate the CSI frame of forming by these difference SNR value (CSI1+CSI2+CSI3).Will be in timing t _4nFrame format be shown in Figure 38.In other words, in timing t _4n, after the SNR of subcarrier 1 value, the difference SNR value between the adjacent subcarrier is sent as CSI.And, can be illustrated in timing t by following formula (5) _4nDifference SNR value Δ γ _{M, 4n}Wherein, in formula (5), γ _{M, 4n}Expression is to the timing t of m subcarrier _4nThe SNR value carry out value (unit [dB]) after the logarithmic transformation.

${\mathrm{\Δ\γ}}_{m,4n}=\left\{\begin{array}{c}{\mathrm{\γ}}_{\mathrm{1,4}n},m=1\\ {\mathrm{\γ}}_{m,4n}-{\mathrm{\γ}}_{m-\mathrm{1,4}n,}m\≠1\end{array}\right.\·\·\·\left(5\right)$

Then, in timing t _4n+1, CSI frame generation unit 386 is obtained in timing t at the subcarrier 7,8,11,16,17,18,19,22 of group 3 _4n+1And timing t _4nBetween difference (difference SNR value) the Δ γ of SNR value _{M, 4n+1}, generate by these difference SNR value Δ γ _{M, 4n+1}The CSI frame of forming (CSI3).Will be in timing t _4n+1Frame format be shown in Figure 39.And, can be illustrated in timing t by following formula (6) _4n+1Difference SNR value Δ γ _{M, 4n+1}

Δγ _m，4n+1＝γ _m，4n+1-γ _m，4n ...(6)

Then, in timing t _4n+2, CSI frame generation unit 386 is asked in timing t at the subcarrier 2,5,6,9,13,15,20,24 of group 2 _4n+2And timing t _4nBetween difference (difference SNR value) the Δ γ of SNR value _{M, 4n+2}, at the subcarrier 7,8,11,16,17,18,19,22 of group 3, ask simultaneously in timing t _4n+2And timing t _4n+1Between difference (difference SNR value) the Δ γ of SNR value _{M, 4n+2}, generate the CSI frame of forming by these difference SNR value (CSI2+CSI3).Make in timing t _4n+2Frame format identical with Figure 39.And, can be illustrated in timing t by following formula (7), formula (8) _4n+2Difference SNR value Δ γ _{K, 4n+2}With Δ γ _{M, 4n+2}Wherein, in formula (7), γ _{K, 4n}Expression is to the timing t of k subcarrier _4nThe SNR value carry out value (unit [dB]) after the logarithmic transformation.

Δγ _k，4n+2＝γ _k，4n+2-γ _k，4n ...(7)

Δγ _m，4n+2＝γ _m，4n+2-γ _m，4n+1 ...(8)

Then, in timing t _4n+3Carry out with in timing t _4n+1Identical processing, and in timing t _{4 (n+1)}Carry out with in timing t _4nIdentical processing.

Then, reuse the action that Figure 35 illustrates the quality level extraction unit 261 of present embodiment.The quality level extraction unit 261 of present embodiment and the action of CSI frame generation unit 386 are carried out action as shown in figure 35 accordingly.

In other words, in timing t _4n, quality level extraction unit 261 receives CSI frame (CSI1+CSI2+CSI3) shown in Figure 38.Then, quality level extraction unit 261 extracts the SNR value of subcarrier 1 and the difference SNR value Δ γ between the adjacent subcarrier from the CSI frame _{M, 4n}, carry out the addition shown in the formula (9) and handle and ask subcarrier 1～24 SNR value Δ γ separately _{M, 4n}, add corresponding subcarrier sequence number and output to line status memory 262.

${\mathrm{\γ}}_{m,4n}=\left\{\begin{array}{c}{\mathrm{\γ}}_{\mathrm{1,4}n},m=1\\ {\mathrm{\γ}}_{m-\mathrm{1,4}n}+{\mathrm{\Δ\γ}}_{m,4n},m\≠1\end{array}\·\·\·\left(9\right)\right.$

Next, in timing t _4n+1, quality level extraction unit 261 receives CSI frame (CSI3) shown in Figure 33.Then, quality level extraction unit 261 is from the difference SNR value Δ γ of the subcarrier 7,8,11,16,17,18,19,22 of CSI frame extraction group 3 _{M, 4n+1}, carry out the addition shown in the formula (10) and handle and obtain subcarrier 7,8,11,16,17,18,19,22 SNR value Δ γ separately _{M, 4n+1}, and with further reference to the subcarrier sequence number of classification results memory 267 from the subcarrier of classification results memory 267 acquisition groups 3.Then, the SNR value γ that obtains of 261 pairs of quality level extraction units _{M, 4n+1}Add corresponding subcarrier sequence number respectively and output to line status memory 262.

γ _m，4n+1＝γ _m，4n+Δγ _m，4n+1 ...(10)

Next, in timing t _4n+2, quality level extraction unit 261 receives the CSI frame (CSI2+CSI3) of the frame format identical with Figure 39.Then, quality level extraction unit 261 is from the difference SNR value Δ γ of the subcarrier 2,5,6,9,13,15,20,24 of CSI frame extraction group 2 _{K, 4n+2}, the difference SNR value Δ γ of the subcarrier 7,8,11,16,17,18,19,22 of extraction group simultaneously 3 _{M, 4n+2}Then, 261 pairs of groups 2 of quality level extraction unit are carried out the addition processing shown in the formula (11), obtain subcarrier 2,5,6,9,13,15,20,24 SNR value γ separately _{K, 4n+2}, carry out the addition processing shown in the formula (12) to organizing 3 simultaneously, obtain subcarrier 7,8,11,16,17,18,19,22 SNR value γ separately _{M, 4n+2}, and with reference to classification results memory 267, from the subcarrier sequence number of the classification results memory 267 acquisition groups 2 and the subcarrier of group 3.Then, the SNR value γ that obtaining of quality level extraction unit 261 _{K, 4n+2}And γ _{M, 4n+2}Add corresponding subcarrier sequence number respectively and output to line status memory 262.

γ _k，4n+2＝γ _k，4n+Δγ _k，4n+2 ...(11)

γ _m，4n+2＝γ _m，4n+1+Δγ _m，4n+2 ...(12)

Then, in timing t _4n+3Carry out with in timing t _4n+1Identical processing, and in timing t _{4 (n+1)}Carry out with in timing t _4nIdentical processing.

Like this, according to present embodiment,, can further cut down the data volume of feedback information because the difference of SNR value is sent as CSI.And, because in the timing t of the CSI of all subcarriers that send subcarrier 1～24 _4nAnd t _{4 (n+1)}, the difference of the SNR value between the adjacent subcarrier is sent as CSI, even in timing t _4n+1～t _4n+3Produce transmission error at CSI2 or CSI3, can prevent that also this error propagation is to timing t _{4 (n+1)}CSI afterwards.

Like this, in the present embodiment, the CSI frame (CSI1+CSI2+CSI3) of CSI of all subcarriers that comprises subcarrier 1～24 is for being used for the important CSI frame that anti-transmission errors is propagated, and it is very important therefore not make this CSI frame produce transmission error.Therefore, in the present embodiment, also can be as shown in figure 40, in timing t _4nAnd t _{4 (n+1)}, coding unit 41 shown in Figure 2 and modulating unit 42 make encoding rate R and modulation level less than other timing t _4n+1～t _4n+3, improve anti-wrong ability thus.

(execution mode 6)

Present embodiment is different with execution mode 4 in the following areas,, at a plurality of subcarriers that will constitute the OFDM code element based on SNR (here for subcarrier 1～24) when being divided into a plurality of groups, omits the transmission of CSI that the SNR value is lower than the group of defined threshold that is.Yet, in following explanation, with execution mode 4 similarly, be that example describes with the situation that subcarrier 1～24 is categorized into three groups.

Now use Figure 41 to describe the structure of the CSI processing unit 38 of present embodiment in detail.In Figure 41, two threshold values of threshold value 1,2 (threshold value 1＞threshold value 2) are imported into taxon 390 and CSI sending controling unit 39.Yet, in Figure 41, give identical label to the structure identical, and omit its explanation with execution mode 4 (Figure 29).

Taxon 390 relatively is stored in the SNR value and the threshold value 1,2 of each subcarrier of line status memory 382, and the result is categorized into three groups with subcarrier 1～24 based on the comparison.Taxon 390 is categorized into group 1 with the SNR value for the subcarrier of threshold value 1 or more, with SNR value for threshold value more than 2 and the subcarrier that is lower than threshold value 1 be categorized into and organize 2, the subcarrier that the SNR value is lower than threshold value 2 is categorized into organizes 3.

Will be in the particular instantiation of the classification of taxon 390 in Figure 42.When the SNR of each subcarrier 1～24 is situation shown in Figure 42, taxon 390 with subcarrier 1～24 based on threshold value 1,2 classification three groups of 1,2,3 in groups.Its result, subcarrier 1,2,3,4,10,12,13,14,15,20,21,23,24 is classified into group 1, and subcarrier 5,6,7,9,11,16,17,18,22 is classified into group 2, and subcarrier 8,19 is classified into group 3.As shown in figure 43, this classification results is stored in classification results memory 389.

CSI frame generation unit 386 is in the timing that generates timing signal from 39 inputs of CSI sending controling unit, based on CSI frame category and the classification results shown in Figure 43 that is stored in classification results memory 389 from 39 inputs of CSI sending controling unit, from subcarrier 1～24, select CSI to be fed back to the subcarrier of CSI receiving system, and generate the CSI frame.CSI frame generation unit 386 moves as shown in figure 44.In example shown in Figure 44, the CSI dispensing device is based at above-mentioned classification results, with three kinds of CSI frame period property feed back to the CSI receiving system.In three kinds of CSI frames of CSI1～CSI3, the CSI frame that CSI1 is made up of the SNR value of group 1 ( subcarrier 1,2,3,4,10,12,13,14,15,20,21,23,24), the CSI frame that CSI2 is made up of the SNR value of group 2 ( subcarriers 5,6,7,9,11,16,17,18,22), the CSI frame that CSI3 is made up of the SNR value of group 3 (subcarriers 8,19).

And,, set frame allocation threshold (threshold value 2≤frame allocation threshold＜threshold value 1) as shown in figure 42 simultaneously to CSI sending controling unit 39 input threshold values 1,2.Then, CSI sending controling unit 39 and CSI frame generation unit 386 move as shown in figure 44, omit CSI frame (that is transmission CSI3), of SNR value composition that is lower than the group (that is group 3) of the threshold value (that is threshold value 2) below the frame allocation threshold by SNR value.

In Figure 44, at first in timing t _4n, generate timing signal and be imported into CSI frame generation unit 386 from CSI sending controling unit 39.Simultaneously, be imported into classification results memory 389, to upgrade the content of classification results memory 390 at the taxon 388 new classification results that obtain owing to upgrade timing signal.Now, the content of the classification results memory 389 after supposing to upgrade is for as shown in figure 43.And, because to the signal of CSI frame generation unit 386 input expressions " CSI1+CSI2+CSI3 " as the CSI frame category, CSI frame generation unit 386 generates the CSI frame (CSI1+CSI2+CSI3) of the SNR value of all subcarriers that comprise subcarrier 1～24 according to indicated CSI frame category from CSI sending controling unit 39.

Then, in timing t _4n+1, generate timing signal and be imported into CSI frame generation unit 386 from CSI sending controling unit 39.But, not being transfused to classification results memory 389 owing to upgrade timing signal, classification results memory 389 is not updated.Therefore, the content of classification results memory 389 is still for as shown in figure 43.And, in timing t _4n+1, the signal of expression CSI frame category is not imported to CSI frame generation unit 386 from CSI sending controling unit 39.Therefore, in the present embodiment, CSI frame generation unit 386 does not generate in the execution mode 4 in timing t _4n+1The CSI3 that generates.As above-mentioned, in the present embodiment, the transmission of CSI3 is omitted.

Then, in timing t _4n+2, will generate timing signal from CSI sending controling unit 39 and be input to CSI frame generation unit 389, be not input to classification results memory 389 but upgrade timing signal, so classification results memory 389 is not updated.Therefore, the content of classification results memory 389 is still for as shown in figure 43.And, owing to represent " CSI2 " signal from CSI sending controling unit 39 to 386 inputs of CSI frame generation unit, the CSI frame (CSI2) that CSI frame generation unit 386 is made up of the SNR value of the subcarrier 5,6,7,9,11,16,17,18,22 of group 2 according to indicated CSI frame category generation as the CSI frame category.In other words, in the present embodiment, CSI frame generation unit 386 is in timing t _4n+2Do not generate in the execution mode 4 in timing t yet _4n+2The CSI3 that generates.

Then, in timing t _4n+3Carry out with in timing t _4n+1Identical processing, and in timing t _{4 (n+1)}Carry out with in timing t _4nIdentical processing.Like this, by not carrying out in timing t _4n+1, t _4n+2, t _4n+3The transmission of CSI3, its result, as shown in figure 44, the transmission cycle (feedback cycle) 107 of CSI3 and the transmission cycle (feedback cycle) 107 of CSI1 similarly become the twice in the transmission cycle (feedback cycle) 106 of CSI2.

Next, use Figure 45 to describe the structure of the CSI processing unit 26 of present embodiment in detail.Yet, in Figure 45, give identical label to the structure identical, and omit its explanation with execution mode 4 (Figure 34).

The action of CSI processing unit 26 shown in Figure 45 and CSI frame generation unit 386 shown in Figure 41 is carried out action shown in Figure 46 accordingly.

In other words, at first in timing t _4n, receive timing signal and be imported into quality level extraction unit 261 from CSI reception control unit 27.And, represent that as the CSI frame category signal of " CSI1+CSI2+CSI3 " is imported into quality level extraction unit 261 from CSI reception control unit 27.Therefore, quality level extraction unit 261 receives the CSI frame (CSI1+CSI2+CSI3) of the SNR value of all subcarriers that comprise subcarrier 1～24.Then, quality level extraction unit 261 extracts subcarrier 1～24 SNR value separately from the CSI frame, adds corresponding subcarrier sequence number and outputs to line status memory 262.Line status memory 262 upgrades the SNR value of all subcarriers.

In addition, in timing t _4n, be imported into classification results memory 267 owing to upgrade timing signal, classification results memory 267 with by taxon 268 in timing t _4nThe classification results that obtains upgrades the classification results that is kept.The sorting technique of taxon 268 is to use the method identical with the taxon 390 of CSI dispensing device.By this processing, can make in timing t _4nThe content of classification results memory 389 of CSI dispensing device and the content synchronization of the classification results memory 267 of CSI receiving system.

Then, in timing t _4n+1, receive timing signal and be imported into quality level extraction unit 261 from CSI reception control unit 27.But, upgrade timing signal and be not imported into classification results memory 267.Therefore, in timing t _4n+1, classification results memory 267 is not updated, and the state of classification results memory 267 maintains t _4nState after the renewal.And, in timing t _4n+1, the signal of expression CSI frame category does not receive control unit 27 from CSI and is input to quality level extraction unit 261.Therefore, quality level extraction unit 261 is not received in the execution mode 4 in timing t _4n+1The CSI3 that accepts.

Then, in timing t _4n+2, receive timing signal and be imported into quality level extraction unit 261 from CSI reception control unit 27.And, represent that as the CSI frame category signal of " CSI2 " is imported into quality level extraction unit 261 from CSI reception control unit 27.But, upgrade timing signal and be not imported into classification results memory 267.Therefore, in timing t _4n+2, classification results memory 267 is not updated, and the state of classification results memory 267 maintains t _4nState after the renewal.

Quality level extraction unit 261 receives the CSI frame of being made up of the SNR value of the subcarrier 5,6,7,9,11,16,17,18,22 of group 2 (CSI2).Then, quality level extraction unit 261 extracts subcarrier 5,6,7,9,11,16,17,18,22 SNR value separately from CSI2, and with reference to classification results memory 267, from the subcarrier sequence number of the subcarrier of classification results memory 267 acquisition groups 2.Then, quality level extraction unit 261 adds corresponding subcarrier sequence number respectively and outputs to line status memory 262 in the SNR value that extracts.

Line status memory 262 upgrades the SNR value corresponding to the subcarrier sequence number of importing from quality level extraction unit 261.In other words, only upgrade the SNR value of the subcarrier 5,6,7,9,11,16,17,18,22 of the group 2 in the subcarrier 1～24.By this processing, can make in timing t _4n+2The content of line status memory 382 of CSI dispensing device and the content synchronization of the line status memory 262 of CSI receiving system.

Then, in timing t _4n+3Carry out with in timing t _4n+1Identical processing, and in timing t _{4 (n+1)}Carry out with in timing t _4nIdentical processing.

In addition, also can be in the timing t of Figure 44 and Figure 45 _4n+1, t _4n+3, do not make to generate timing signal and receive timing signal to be input to CSI frame generation unit 386 and quality level extraction unit 261.

In addition, can be the frame allocation threshold also with threshold value 2 dual-purposes.

Like this, according to present embodiment, owing to economize transmission a little less than the CSI of the group of defined threshold, can cut down the lifting of the throughput feedback data amount of the subcarrier of tool contribution (being subcarrier 8,19 here) not, therefore can cut down the feedback data amount and do not reduce the throughput characteristic.

Next, the setting example of frame allocation threshold is described.

＜setting example 1 〉

Minimum reception SNR value or minimum received power value are set at the frame allocation threshold.So-called minimum reception SNR value (minimum received power value) is the value that expression can not communicate with the SNR value (performance number) that is lower than this value.Therefore, even the CSI of this subcarrier below minimum reception SNR value (minimum received power value) of feedback can not be used for this subcarrier data and send.

＜setting example 2 〉

To be the frame allocation threshold with the corresponding selection threshold setting of the modulation system of modulation level minimum in the selectable a plurality of modulation systems modulation system of tool robustness (that is).Be used for the communication system that data send at the subcarrier that will be lower than minimum reception SNR value,, do not need to feed back continually CSI owing to be lower than the subcarrier of the selection threshold value corresponding with the modulation system of tool robustness with the modulation system transmission of tool robustness.

＜setting example 3 〉

According to time fluctuation speed setting frame allocation threshold as the value (for example, SNR value) of CSI.For example, the time fluctuation speed of SNR value is along with moving with moving of peripheral object of travelling carriage produces.And when the translational speed of travelling carriage was high more, the feedback cycle of CSI was short more.And, in the present invention,, hour make feedback cycle short more more in the SNR value as above-mentioned.In addition, can not feed back with the cycle also shorter than the shortest feedback cycle of allowing in the communication system.Therefore, become the CSI of the feedback cycle that is lower than this shortest feedback cycle frame, set the frame allocation threshold corresponding with the time fluctuation speed of SNR value in order not send.

＜setting example 4 〉

Transfer rate based on data is set the frame allocation threshold.For example, as ofdm system, a plurality of sub-carrier allocation are being given in the communication system of a plurality of travelling carriages, distribute more subcarrier to give the high travelling carriage of data transmission rate, and the low travelling carriage of data transmission rate only is being assigned to few subcarrier.Therefore, the travelling carriage high to data transmission rate set the frame allocation threshold lower, and the travelling carriage low to data transmission rate set the frame allocation threshold higher, can control the quantity of the subcarrier that CSI is fed thus.

(execution mode 7)

In the present embodiment, it is different with execution mode 3 MCS (Modulation and Coding Scheme) value to be sent this respect as CSI.

Now use Figure 47 to describe the structure of the CSI processing unit 38 of present embodiment in detail.Yet, in Figure 47, give identical label to the structure identical, and omit its explanation with execution mode 3 (Figure 23).

The SNR value of each subcarrier of being measured by quality level determination unit 381 is imported into MCS converter unit 391.

MCS converter unit 391 is the MCS value with the SNR value transform of each subcarrier.Conversion from the SNR value to the MCS value is carried out shown in Figure 48,49.In other words, MCS converter unit 391 is SNR value and threshold value TH1～TH7 relatively, and the result is a MCS value 0～7 with the SNR value transform based on the comparison.Specifically, for example the SNR value to be positioned at TH4 above and when being lower than the scope of TH3, at Figure 48, the MCS corresponding with this SNR value is QPSK, and R=3/4 is at Figure 49, with QPSK, the MCS value of the MCS correspondence of R=3/4 is 4, so MCS converter unit 391 is MCS value=4 with this SNR value transform.In addition, when the SNR value is lower than TH7, is considered as to receive and is MCS value=0 this SNR value transform.The MCS value of each subcarrier of conversion in the above described manner is imported into line status memory 382.

Line status memory 382 keeps from the MCS value of each subcarrier of MCS converter unit 391 inputs.

Threshold calculations unit 392 on average is stored in the MCS value of each subcarrier in the line status memory 382 in the hope of average MCS value on all subcarriers, use this average MCS value to set the threshold value of comparing unit 384.The detailed description of threshold calculations unit 392 is with aftermentioned.

384 pairs of threshold values that calculate in threshold calculations unit 392 of comparing unit compare with the MCS value that is stored in each subcarrier of line status memory 382.

Comparative result memory 385 is stored the comparative result of comparing unit 384 and is kept by each subcarrier.The memory contents of comparative result memory 385 is updated according to the renewal timing signal from 39 inputs of CSI sending controling unit.

Then, use Figure 50 to describe the threshold calculations unit 392 shown in Figure 47 in detail.Yet, in Figure 50, give identical label to the structure identical, and omit its explanation with execution mode 3 (Figure 24).

MCS/ logarithmic transformation unit 3876 is the SNR value based on Figure 48,49 with the MCS value transform that is stored in each subcarrier of line status memory 382.In other words, MCS/ logarithmic transformation unit 3876 carries out the conversion opposite with the conversion of MCS converter unit 391.Particularly, for example, the MCS value of input is 4 o'clock, and MCS/ logarithmic transformation unit 3876 is with the SNR value of this MCS value transform value that is TH4.At this, MCS value=4 are transformed to the SNR value of the value of the SNR value of value of TH4 rather than TH3, this is for by being transformed to QPSK, the selecteed prescribed limit of the MCS of R=3/4 (promptly, TH4 is above and be lower than the scope of TH3) SNR value in lower limit TH4, prevent that SNR value after the conversion is greater than the SNR value in the reality of quality level determination unit 381 mensuration.The SNR value of each subcarrier of conversion in the above described manner is imported into logarithm/linear transform unit 3871.

On the other hand, MCS converter unit 3877 is with the action identical with MCS converter unit 391, will be transformed to the MCS value from the average SNR value [dB] of giving after the skew that unit 3875 inputs are given in skew.Thus, can obtain the threshold value used at comparing unit 384.

Then, comparing unit 384 relatively remains on the MCS value and the threshold value of each subcarrier of line status memory 382, and this comparative result is write comparative result memory 385.

In addition, the processing after the writing of compared result memory 385 is identical with execution mode 3, its explanation of Therefore, omited.But the CSI frame format of present embodiment such as Fig. 9, shown in Figure 180 replace the SNR value with the MCS value.

In addition, the CSI processing unit 26 of present embodiment is extracting MCS value this point by quality level extraction unit 261, and it is different with execution mode 3 (Figure 26) similarly to calculate the threshold value this point of MCS value by threshold calculations unit 264 and threshold calculations unit 392, other parts are then identical with execution mode 3, its explanation of Therefore, omited.

Have again, also can give unit 3875 and set a plurality of threshold values, the MCS value of each subcarrier is categorized into group more than three by average SNR value [dB] being given mutually different a plurality of skews by skew.Also can be similarly at execution mode 3, the SNR value of each subcarrier is categorized into group more than three.

Like this,,, compare as the situation of CSI, can further cut down the data volume of feedback information with making SNR because the MCS value of each subcarrier is transmitted as CSI according to present embodiment.Especially in the communication system of carrying out Adaptive Modulation, when the receiving terminal by the data of passing through Adaptive Modulation determines MCS and feeds back to transmitting terminal, the feedback of needs Adaptive Modulation can be carried out according to present embodiment together, thereby more efficient feedback can be carried out.

(execution mode 8)

In the present embodiment, use the time fluctuation amount, SNR value of transmission path response at the variance yields (variance SNR value) of frequency domain, at the mean value (average SNR value) of the SNR of all subcarriers, the control that transmission cycle of the interval of the quantity of the numerical value of threshold value, threshold value, threshold value, CSI frame is suited.

Now use Figure 51 to describe the structure of the CSI dispensing device of present embodiment in detail.Yet, in Figure 51, give identical label to the structure identical, and omit its explanation with execution mode 1 (Fig. 2).

The time fluctuation amount of transmission path response is measured in time fluctuation quantitative determination unit 51 from the transmission path response of each subcarrier.For example in " three bottles of political affairs one, " basic Foundation か ら シ ス テ system Let Meter ま In デ イ ジ Le ワ イ ヤ レ ス Den send skill Intraoperative ", ピ ア ソ Application ェ デ ユ ケ one シ ヨ Application, in September, 2002,2.4.6 Festival (page 33-35) ", put down in writing relevant at the unify observation procedure of decline change of polar coordinate system of orthogonal coordinate system.So time fluctuation amount computing unit 51 is for example measured the time fluctuation amount of transmission path response by following mode.

＜mensuration example 1 〉

To use the mensuration of time fluctuation amount of the transmission path response of polar coordinate system to be illustrated in Figure 52.Shown in Figure 52, the change setting threshold of the envelope of 51 pairs of transmission path responses in time fluctuation quantitative determination unit, in being determined between the test period of regulation this change from top to bottom with the number of times of threshold crossings (or from the bottom up with threshold crossings), measure the time fluctuation amount of the time per unit of transmission path response.

＜mensuration example 2 〉

Shown in Figure 53, in time fluctuation quantitative determination unit 51, the time fluctuation of the amplitude of observation I-ch or Q-ch is measured the number of times that the time per unit of the direction (symbol of differential value) of this change changes, and measures the time fluctuation amount of the time per unit of transmission path response.

＜mensuration example 3 〉

Time fluctuation quantitative determination unit 51 detects maximum doppler frequency, measures the time fluctuation amount of the time per unit of transmission path response from maximum doppler frequency.

And the SNR computing unit 52 among Figure 51 adopts the structure shown in Figure 54, calculates average SNR value and variance SNR value.

In Figure 54, the quality level determination unit 381 of quality level determination unit 521 and execution mode 1 is similarly measured the SNR of each subcarrier from the transmission path response that is responded each subcarrier of estimation unit 37 inputs by transmission path.

Average SNR computing unit 522 calculates the average SNR value of all subcarriers from the SNR value of each subcarrier.

The variance SNR value that average SNR computing unit 523 calculates all subcarriers from the SNR value and the average SNR value of each subcarrier.

More particularly, average SNR value and variance SNR value are calculated by following mode.

Average SNR computing unit 522 is with the SNR value γ of each subcarrier _{M, k}From the dB value transform is the SNR value Γ of true value _{M, k}After, based on above-mentioned formula (2), at SNR value (true value) Γ of average each subcarrier of all subcarriers _{M, k}, calculate average SNR value (true value).And average SNR computing unit 522 similarly calculates the average SNR value of dB value.

Variance SNR computing unit 523 is with the SNR value γ of each subcarrier _{M, k}From the dB value transform is the SNR value Γ of true value _{M, k}After, based on formula (13) from SNR value Γ _{M, k}Calculate variance SNR value (true value) with the average SNR value (true value) that calculates at average SNR computing unit 522.And variance SNR computing unit 523 obtains the variance SNR value of dB value by linearity-logarithmic transformation from variance SNR value (true value).

$V\left({\mathrm{\Γ}}_k\right)=\frac{1}{M}\underset{m=1}{\overset{M}{\mathrm{\Σ}}}{({\mathrm{\Γ}}_{m,k}-E\left({\mathrm{\Γ}}_k\right))}^2\·\·\·\left(13\right)$

In addition, as the parameter of the frequency variation of representing the transmission path response, can use following parameter to replace variance SNR value.

The mean change amount of instantaneous SNR

$u_k=\frac{1}{M}\underset{m=1}{\overset{M}{\mathrm{\Σ}}}|{\mathrm{\Γ}}_{m,k}-E\left({\mathrm{\Γ}}_k\right)|\·\·\·\left(14\right)$

The maximum variable quantity of instantaneous SNR

$v_k=\underset{1\&le;m\&le;M}{\mathrm{<figure-callout\; id="1"\; label="max"\; filenames="A20058003058800491.png,A20058003058800501.png"\; state="\{\{state\}\}">max</figure-callout>}}\left|\right|{\mathrm{\&Gamma;}}_{m,k}-E\left({\mathrm{\&Gamma;}}_k\right)\left|\right|\&CenterDot;\&CenterDot;\&CenterDot;\left(15\right)$

The maximum variable quantity of instantaneous SNR square

$x_k=\underset{1\&le;m\&le;M}{\mathrm{<figure-callout\; id="1"\; label="max"\; filenames="A20058003058800491.png,A20058003058800501.png"\; state="\{\{state\}\}">max</figure-callout>}}{\left|\right|{\mathrm{\&Gamma;}}_{m,k}-E\left({\mathrm{\&Gamma;}}_k\right)\left|\right|}^2\&CenterDot;\&CenterDot;\&CenterDot;\left(16\right)$

Instantaneous SNR's is minimum and maximum poor

$z_k=\frac{1}{2}|\underset{1\&le;m\&le;M}{\mathrm{<figure-callout\; id="1"\; label="max"\; filenames="A20058003058800491.png,A20058003058800501.png"\; state="\{\{state\}\}">max</figure-callout>}}{\mathrm{\&Gamma;}}_{m,k}-\underset{1\&le;m\&le;M}{\mathrm{<figure-callout\; id="1"\; label="min"\; filenames="A20058003058800491.png,A20058003058800501.png"\; state="\{\{state\}\}">min</figure-callout>}}{\mathrm{\&Gamma;}}_{m,k}|\&CenterDot;\&CenterDot;\&CenterDot;\left(17\right)$

Poor square with minimum square of the maximum of instantaneous SNR

$d_k=\underset{1\&le;m\&le;M}{\mathrm{<figure-callout\; id="1"\; label="max"\; filenames="A20058003058800491.png,A20058003058800501.png"\; state="\{\{state\}\}">max</figure-callout>}}{\left|{\mathrm{\&Gamma;}}_{m,k}\right|}^2-\underset{1\&le;m\&le;M}{\mathrm{<figure-callout\; id="1"\; label="min"\; filenames="A20058003058800491.png,A20058003058800501.png"\; state="\{\{state\}\}">min</figure-callout>}}{\left|{\mathrm{\&Gamma;}}_{m,k}\right|}^2\&CenterDot;\&CenterDot;\&CenterDot;\left(18\right)$

CSI processing unit 38 and CSI handle time fluctuation amount, average SNR value (dB value) and the variance SNR value (dB value) of sending controling unit 39 according to the transmission path response, shown in Figure 55, the numerical value of threshold value, the quantity of threshold value, the interval of threshold value, the transmission cycle of CSI frame are controlled.Enumerate several typical control examples below.

＜control example 1: based on the control of the numerical value of the threshold value of the time fluctuation amount of transmission path response 〉

When the time fluctuation amount of transmission path response was big, it is big that the time fluctuation of the SNR of subcarrier integral body also becomes.On the contrary, in the time fluctuation amount of transmission path response hour, the time fluctuation of the SNR of subcarrier integral body also diminishes.So, at CSI processing unit 38, for the distribution of the CSI frame that cooperates the time fluctuation amount is controlled, when the time fluctuation amount of transmission path response is big, improve threshold value, in the time fluctuation amount hour reduction of transmission path response threshold value to the SNR value to SNR value.According to this control, CSI frame based on the time fluctuation speed of the channel of each subcarrier is distributed becomes possibility, can cut down the feedback data amount and receptivity is worsened.

＜control example 2: based on the control of the quantity of the threshold value of average SNR value 〉

When the average SNR value is high, even the low subcarrier of SNR value also can adopt the modulation system of tool robustness, can communicate, so CSI processing unit 38 increases the quantity of threshold values and increases the kind of CSI frame with all subcarriers.On the contrary, when the average SNR value was hanged down, because the low subcarrier of SNR value is included in noise region, so CSI processing unit 38 reduced the quantity of threshold value.

＜control example 3: based on the control at the interval of the threshold value of variance SNR value 〉

When variance SNR value was big, the scope that the SNR value of each subcarrier is desirable became big.On the contrary, variance SNR value hour, the desirable scope of SNR value of each subcarrier diminishes.So CSI processing unit 38 increases the interval of threshold value for cooperating the variation of such scope when variance SNR value is big, hour reduce the interval of threshold value in variance SNR value.

＜control example 4: based on the control of the quantity of the threshold value of variance SNR value 〉

When variance SNR value was big, the scope that the SNR value of each subcarrier is desirable became big.On the contrary, variance SNR value hour, the desirable scope of SNR value of each subcarrier diminishes.So CSI processing unit 38 increases the quantity of threshold value for cooperating the variation of such scope when variance SNR value is big, in the quantity of variance SNR value hour minimizing threshold value.

And, the CSI frame generation unit 386 of CSI processing unit 38 inside is to be shared for the threshold value and the setting in the cycle of transmission by CSI dispensing device and CSI receiving system, the frame format of the time fluctuation amount, average SNR value and the variance SNR value that comprise transmission path response of use shown in Figure 56 is to replace frame format shown in Figure 9.Like this, by feeding back time fluctuation amount, average SNR value and the variance SNR value of all transmission path responses, becoming at the CSI receiving system does not need these calculating.In addition, average SNR value and variance SNR value can calculate in the SNR value of CSI receiving system from all subcarriers, CSI frame generation unit 386 also can use the frame format that does not comprise average SNR value and variance SNR value shown in Figure 57, to replace frame format shown in Figure 9.

Next, use Figure 58 to describe the structure of the CSI processing unit 26 of present embodiment in detail.Structure shown in Figure 58 is, the structure of the CSI processing unit 26 when the CSI dispensing device uses frame format shown in Figure 57.When the CSI dispensing device used the frame format of Figure 56, becoming did not need average SNR computing unit 268 and variance SNR computing unit 269.Yet, in Figure 58, give identical label to the structure identical, and omit its explanation with execution mode 3 (Figure 26).

Quality level extraction unit 261 extracts the SNR value of each subcarrier from the CSI frame, outputs to line status memory 262 with the subcarrier sequence number.And quality level extraction unit 261 extracts the time fluctuation amount of transmission path response from the CSI frame, outputs to threshold parameter decision unit 270.

Average SNR computing unit 268 calculates the average SNR value by the processing identical with the average SNR computing unit 522 of Figure 54.And variance SNR computing unit 269 calculates difference of two squares SNR value by the processing identical with the variance SNR computing unit 523 of Figure 54.

Threshold parameter decision unit 270 is according to Figure 55, and the control information based on the interval of the quantity of the numerical value of time fluctuation amount, average SNR value and the relevant threshold value of variance SNR value generation of transmission path response, threshold value and threshold value outputs to threshold calculations unit 264.

Then, threshold calculations unit 264 is according to this control information calculated threshold.

By such action of CSI processing unit 26, can set and the identical threshold value of using at the CSI dispensing device of threshold value at the CSI receiving system.

Like this, in the present embodiment, the setting of the setting of the distribution of the CSI frame that can suit, suitable CSI number of frames and suitable feedback cycle according to time fluctuation amount, average SNR value and the variance SNR value of transmission path response, thus can cut down the data volume of feedback information and do not make by adaptive control and be adjusted to best throughput characteristic reduction.

It more than is the explanation of embodiment of the present invention.

Yet, in the above-described embodiment, illustrated by radio communication device shown in Figure 2 to send CSI that radio communication device shown in Figure 1 is based on the structure of the CSI decision modulation parameter that receives.But, also can adopt the structure that sends modulation parameter rather than CSI by radio communication device shown in Figure 2.In other words, it also can be the modulation parameter that determines each subcarrier (frequency range) by radio communication device shown in Figure 2 based on quality level, similarly send modulation parameter with the transmission of above-mentioned CSI, by radio communication device shown in Figure 1 based on the modulation parameter that receives encode, the structure of modulation, transmission power control.

In addition, in the above-described embodiment, though the kind of CSI frame is illustrated as two kinds, also can set the kind that a plurality of threshold values make the CSI frame is more than three kinds.

Have, frequency range is also sometimes referred to as Resource Block, subchannel, subcarrier block, subband or piece (chunk) again.

In addition, radio communication terminal device (travelling carriage) is called as UE sometimes, and radio communication base station device is called as Node B sometimes, and subcarrier is called as tone sometimes.

Have, constituting situation of the present invention with hardware in the above-described embodiment is that example is illustrated again, but the present invention also can realize with software.

Have, each functional block in the explanation of above-mentioned execution mode can be embodied as general LSI as integrated circuit again.These pieces both each piece be integrated into a chip respectively, perhaps can be some or all and be integrated into a chip.

And,,, can be called IC, system LSI, senior LSI (Super LSI) or super LSI (Ultra LSI) according to degree of integration though be called LSI herein.

In addition, realize that the method for integrated circuit is not limited only to LSI, also can use special circuit or general processor to realize.After LSI makes, programmable FPGA (Field Programmable GateArray) be can utilize, the connection of circuit unit of restructural LSI inside or the reconfigurable processor of setting perhaps can be used.

Have again,,, can utilize this technology to carry out the integrated of functional block certainly if the new technology of LSI integrated circuitization can occur substituting along with semi-conductive technological progress or the appearance of the other technologies of derivation thereupon.And exist the possibility that is suitable for biotechnology.

This specification is based on the Japanese patent application of Japanese patent application of submitting on September 10th, 2004 2004-264606 number and submission on August 26th, 2005 2005-246088 number.Its content all is contained in this for reference.

Industrial applicibility

The present invention is applicable to that radio communication base station device and the radio communication used are whole in GSM End device etc.

Claims (7)

1, a kind of radio communication device comprises:

Receiving element receives the multi-carrier signal that consists of a plurality of subcarriers;

Determination unit is measured each subcarrier of described multi-carrier signal or the quality level of each frequency range;

Comparing unit compares the variation and the threshold value of described quality level or described quality level; And

Transmitting element, send described quality level with first feedback cycle and be lower than a part of subcarrier of described threshold value or a part of frequency range or described variation and surpass a part of subcarrier of described threshold value or the CSI or the modulation parameter of a part of frequency range, and send the CSI or the modulation parameter of all subcarriers or all frequency ranges with second feedback cycle greater than described first feedback cycle.

2, radio communication device as claimed in claim 1, wherein

Described transmitting element will send as CSI at the comparative result of described comparing unit.

3, radio communication device as claimed in claim 1 wherein, also comprises:

Setup unit uses the mean value or the median of the described quality level of described a plurality of subcarriers to set described threshold value.

4, radio communication device as claimed in claim 1 wherein, also comprises:

Generation unit, generate first frame and second frame, this first frame is made up of subcarrier or frequency range that described quality level surpasses described threshold value, perhaps be lower than the subcarrier of described threshold value or the CSI or the modulation parameter of frequency range formed by described variation, this second frame is made up of subcarrier or frequency range that described quality level is lower than described threshold value, perhaps form above the subcarrier of described threshold value or the CSI or the modulation parameter of frequency range by described variation

Described transmitting element sends described first frame with the feedback cycle of the integral multiple of the feedback cycle of described second frame.

5, a kind of radio communication terminal device comprises radio communication device as claimed in claim 1.

6, a kind of radio communication base station device comprises radio communication device as claimed in claim 1.

7, a kind of wireless communications method comprises:

Receiving step receives the multi-carrier signal that consists of a plurality of subcarriers;

Determination step is measured each subcarrier of described multi-carrier signal or the quality level of each frequency range;

Comparison step compares the variation and the threshold value of described quality level or described quality level; And

Forwarding step, send described quality level with first feedback cycle and be lower than a part of subcarrier of described threshold value or a part of frequency range or described variation and surpass a part of subcarrier of described threshold value or the CSI or the modulation parameter of a part of frequency range, and send the CSI or the modulation parameter of all subcarriers or all frequency ranges with second feedback cycle greater than described first feedback cycle.

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