CN101540690B - Method and system for MIMO communication of multicast service - Google Patents

Abstract

The embodiment of the invention relates to a method and a system for MIMO communication of multicast service. At least two transmitting antennae are alternately used through a transmitter to transmit all data stream signals encoded by an independent channel, at least one data stream adopts a higher-order modulation coding way than other data streams or the transmitting power of at least one data stream is lower than that of other data streams; and a receiver is used for receiving all data streams transmitted through the transmitting antennae. The method and the system for MIMO communication of the multicast service of the embodiment perform disturbance elimination detection to the different data streams through the receiver of each terminal according to the unified sequence by alternately using all the transmitting antennae to transmit different data stream signals so as to further enhance the channel transmission performance, has better receiving performance to all the receiving terminals and overcomes the defect that one path of data stream signals is transmitted by regularly using one transmitting antenna.

Description

The MIMO communication means and the system of Multimedia Broadcast Multicast Service

Technical field

The present invention relates to communication technical field, particularly a kind of MIMO communication means and system of Multimedia Broadcast Multicast Service.

Background technology

In the wireless channel environment of mobile communication system since such as multipath interference, shade, waveform attenuating, the time become factor noise and the decline, send signal and can incur loss inevitably.This loss of signal meeting causes the serious distortion that sends signal, reduces the performance of whole system.In wireless communication system, alleviate multipath fading by diversity technique.This diversity technique is divided into time diversity, frequency diversity and antenna diversity.Antenna diversity is the more diversity form of using in the mobile communication, briefly, adopts a plurality of reception antennas to come received signal exactly, merges then.The antenna diversity pattern is divided into the reception antenna diversity of using a plurality of reception antennas, use the transmitting antenna diversity of a plurality of transmitting antennas and the multiple-input and multiple-output (MIMO of a plurality of transmitting antennas of use and a plurality of reception antennas, Multiple Input Multiple Output, multiple-input and multiple-output) antenna diversity.MIMO sends the Space Time Coding (STC that expands to the spatial domain with predetermined coding method encoded signals, with time domain coding by a plurality of transmitting antennas, Space Time Coding, Space Time Coding) special circumstances, its purpose is to improve message transmission rate or bit error rate.

Space-Time Block Coding (STBC, Space Time Block Coding, Space-Time Block Coding) is a kind of space time coding scheme, and STBC utilizes the space diversity of signal, makes mimo system can obtain bigger channel capacity and signal gain.The Space-Time Block Coding of Alamouti pattern is a simple and classical example of Space-Time Block Coding.In Alamouti Space-Time Block Coding technology, transmitter uses two or more transmission antennas transmit signal simultaneously, can use one or more reception antenna received signals at receiver.When transmitter uses two or more transmitting antennas simultaneously, for receiver, can obtain the diversity gain of these two transmitting antennas.

The emission matrix of Alamouti Space-Time Block Coding (STBC) can be expressed as:

Emission matrix I: $\left[\begin{array}{cc}{a}_1& -a_2^{*}\\ a_2& a_1^{*}\end{array}\right]---\left(1\right)$

Wherein, the row of this emission matrix is represented antenna 1 and antenna 2 respectively, and row are represented symbol period 1 and symbol period 2 respectively.The situation that above-mentioned symbol period 1 and symbol period 2 satisfy channel in these two symbol periods changes can be regarded as approximate constantly more slowly, and these two symbol periods are normally adjacent on frequency domain or time domain.These two symbol periods are under situation adjacent on the time domain, are considered to the Alamouti Space-Time Block Coding (STBC) of narrow sense usually; And work as these two symbol periods is under situation adjacent on the frequency domain, is commonly referred to as Alamouti SFBC (Space Frequency Block Coding, space-time/frequency block code).In embodiments of the present invention, the Space-Time Block Coding that is called of the Space-Time Block Coding of narrow sense and space-time/frequency block code unification; That is to say that, Space-Time Block Coding can refer to the Space-Time Block Coding of narrow sense, also can refer to space-time/frequency block code herein, based on context concrete implication can be determined.

Wherein, a symbol period refers to an interval that symbol takies by Channel Transmission, the interval that perhaps takies, the perhaps interval that takies on the two dimensional surface of time domain and frequency domain on frequency domain on time domain.For example, the document of IEEE 802.20 standard 2006-01-06 " MBFDD and MBTDD:Proposed DraftAir Interface Specification " described MIMO OFDM (Orthogonal FrequencyDivision Multiple, OFDM) in the communication plan, packet uses 8 OFDM symbols on the time domain, each OFDM symbol takies 16 subcarriers on the frequency domain, symbol period so, just be meant an interval on the two dimensional surface of time domain and frequency domain, 1 subcarrier on 1 OFDM symbol on the time domain just, and this packet has 8 * 16=128 symbol period.

In addition, many code words (MCW) communication plan that also has a kind of MIMO.In the MCW of MIMO communication plan, there is multichannel to transmit, independently Turbo encoding scheme is all adopted separately on each road.For many patterns of code words, receiving terminal uses interference cancellation techniques can obtain very big gain, so many patterns of code words are used the non-linear receiver of interference eliminated usually.Receiving terminal is according to received signal, the Turbo of elder generation decodes, and riches all the way penetrates signal, after the decoding, whether the decoding of judging this road signal according to check digit is correct, if correct, then use decoded results, from received signal, eliminate the influence that transmits that this road has been correctly decoded, again according to the described received signal of having eliminated after the influence, decode another road of Turbo transmits; Carry out above-mentioned step like this iteratively, transmit up to all multichannels of decoding.

This many code words scheme is the scene design of MIMO at clean culture, receiving terminal need feed back CQI (the Channel Quality Indicator on each road that described multichannel transmits usually, the channel quality indication) information, transmitting terminal carries out AMC (Automatic Modulation and Coding according to each road that the CQI value that receives transmits to multichannel then, adaptive modulation and coding), be MCS (the Modulation and Coding Scheme that each road of adaptive adjustment transmits, modulation coding mode), higher riches all the way penetrates MCS that signal adopts higher-order with the transmission more data in the CQI value, and lower riches all the way penetrates the MCS of signal employing lower-order in CQI value.For MBS (Multicast ﹠amp; BroadcastService, multicast and broadcasting service) scene because a plurality of receiving terminals are arranged, so can not all be fed back the CQI value on each road that multichannel transmits by each receiving terminal, transmitting terminal carries out AMC more thus.Thereby under the scene of MBS, how transmitting terminal adjusts the MCS that each road transmits, and makes a plurality of receiving terminals obtain receptivity preferably, is the problem that needs solve.

Summary of the invention

The embodiment of the invention provides a kind of signal transmitting method of Multimedia Broadcast Multicast Service, to realize the raising of the diversity gain that a plurality of antennas transmit under the MBS scene.

The embodiment of the invention provides a kind of communication means that is used for the mimo system of Multimedia Broadcast Multicast Service on the one hand, comprising:

Use each traffic spike of at least two transmission antennas transmit independent channel codings in turn, wherein, at least one described data flow adopts the modulation coding mode than other data flow high-order, perhaps is lower than other data flow for the transmitting power of at least one described distribution of flows;

Receive described each data flow of described transmission antennas transmit.

The embodiment of the invention provides a kind of communication system that is used for the mimo system of Multimedia Broadcast Multicast Service on the other hand, comprising:

Transmitter, be used to flow each data flow wheel signal of at least two transmission antennas transmit independent channel codings of use, wherein, at least one described data flow adopts the modulation coding mode than other data flow high-order, perhaps is lower than other data flow for the transmitting power of at least one described distribution of flows;

A plurality of receivers are used to receive described each data flow of described transmission antennas transmit.

By above technical scheme as can be known, the MIMO communication means and the system of the Multimedia Broadcast Multicast Service of the embodiment of the invention, by using the different traffic spike of each transmission antennas transmit in turn, and the unified order of the receiver regulation of each terminal is carried out interference eliminated to different data flow detect, thereby can improve the performance of Channel Transmission, all receiving terminals all there is receptivity preferably, overcomes the fixing above-mentioned defective of using a certain transmission antennas transmit one circuit-switched data stream signal.

Also in conjunction with the accompanying drawings the present invention is described in further detail below by specific embodiment.

Description of drawings

Fig. 1 is the schematic flow sheet of the MIMO communication means embodiment one of Multimedia Broadcast Multicast Service of the present invention;

Fig. 2 is the schematic flow sheet of the MIMO communication means embodiment two of Multimedia Broadcast Multicast Service of the present invention;

Fig. 3 is the schematic flow sheet of the MIMO communication means embodiment six of Multimedia Broadcast Multicast Service of the present invention;

Fig. 4 is the structural representation of the MIMO communication system embodiment of Multimedia Broadcast Multicast Service of the present invention.

Embodiment

In standard, Multimedia Broadcast Multicast Service MBS is widely used.Wherein, a scene commonly used is that the base station has 4 transmitting antennas, the rarest 2 reception antennas of portable terminal, described transmitting antenna is physical antenna or virtual-antenna, all can be physical antenna or virtual-antenna at the transmitting antenna described in the following embodiment.Under the MBS scene, the base station is fit to adopt quasi-orthogonal STBC emission matrix to transmit, and promptly per two antennas are launched one group of Alamouti Space-Time Block Coding (STBC), and 4 transmitting antennas of base station are launched two groups of Alamouti Space-Time Block Codings (STBC) altogether.In addition,, it is also conceivable that and use many patterns of code words that because for many patterns of code words, receiving terminal uses interference cancellation techniques can obtain very big gain for the application scenarios of MBS.The embodiment of the invention has designed the communication plan of more excellent mimo system promptly at the application scenarios of MBS.

As shown in Figure 1, be the schematic flow sheet of the MIMO communication means embodiment one of Multimedia Broadcast Multicast Service of the present invention, concrete steps are as follows:

Step 101, each traffic spike that uses at least two transmission antennas transmit independent channels to encode in turn; Wherein, at least one data flow adopts the modulation coding mode than other data flow high-order, perhaps is lower than other data flow for the transmitting power of at least one distribution of flows;

For example, there are 2 transmitting antennas the base station, and each portable terminal has the used emission matrix of the scene of 2 reception antennas to be:

$\left[\begin{array}{cc}{t}_1& s_2\\ s_1& t_2\end{array}\right]$

Top emission matrix represents to adopt many patterns of code words, and promptly t represents an independent channel coded data stream, and s represents another one independent channel coded data stream.Each transmitting antenna of each line display of above-mentioned emission matrix, each tabulation shows that each symbol period, this emission matrix comprise 2 symbol periods.Transmitting antenna wherein can be actual physical antenna, perhaps virtual-antenna.At a Transmission Time Interval (Transition Time Interval, hereinafter to be referred as: TTI) Nei a plurality of symbol periods, the detailed embodiment that transmitting terminal uses above-mentioned emission matrix to transmit is: at the 1st symbol period of a TTI, data flow t after transmitting antenna 1 transfer encoding, the data flow s after transmitting antenna 2 transfer encodings; At 2nd symbol period adjacent of this TTI, the data flow s after transmitting antenna 1 transfer encoding, the data flow t after transmitting antenna 2 transfer encodings with described the 1st symbol period; At 3rd symbol period adjacent of this TTI, transmitting antenna 1 transmitting data stream t, transmitting antenna 2 transmitting data stream s with described the 2nd symbol period; At 4th symbol period adjacent of this TTI, transmitting antenna 1 transmitting data stream s, transmitting antenna 2 transmitting data stream t with described the 3rd symbol period; So, a plurality of symbol periods in a TTI use above-mentioned emission matrix to transmit, and can realize using in turn 2 transmission antennas transmit data flow s and data flow t.Transmission corresponding to 2 kinds of data flow, it is the situation of signal emission, all need in a TTI, travel through, be that data flow s can be regarded as identical with the channel that data flow t is experienced, so, under the situation of not considering the receiver interference cancellation gain, the channel quality indicator (CQI) of data flow s and data flow t is identical;

TTI mentioned above is: in order to resist channel fading, and the error of transmission that brings of the interference of channel and noise, transmitting terminal is divided into a plurality of packets (Block) to the data of needs transmission, information bit in the same packet is carried out chnnel coding and interweaves, be modulated into a plurality of symbols again by Channel Transmission, and the length of transmitting so needed time of packet has determined the length of a TTI.Receiving terminal receives all symbols that comprise in the same packet earlier, carries out deinterleaving and decoding again.In the present invention, a TTI just is meant the time interval of transmitting such packet.

Two symbol periods of mentioned above certain are adjacent, are meant that these two symbol periods satisfy in frequency domain or the adjacent condition of time-domain; And in actual communication systems, some symbol period is used to launch frequency pilot sign, thereby can not be used for transmitted data symbols; Also non-conterminous physically for two symbol periods that certain two data symbol is shared, but the interval is useful on the situation of one or more symbol period (generally being a symbol period) of emission frequency pilot sign, and we think that also two shared symbol periods of described two data symbols are adjacent.And distribute in same user's a plurality of OFDM symbols and a plurality of subcarrier, the 1st subcarrier on last 1 subcarrier on 1 OFDM symbol and adjacent following 1 the OFDM symbol is considered to adjacent; The 1st OFDM symbol on last 1 OFDM symbol on 1 subcarrier and adjacent following 1 subcarrier also is considered to adjacent; This is because in the standard of ofdm communication system, and easy for standard formulation ignored their non-conterminous in fact physically these characteristics, and that this is ignored the influence of systematic function is smaller.

Each data flow of step 102, reception transmission antennas transmit.

According to the above-mentioned emission matrix that provides, can stipulate, the reception antenna of the receiver of one or more terminal can adopt interference excision detection technology, modulation coding mode coded data to low order flows earlier, for example data flow s detects, in received signal, eliminate the interference of the data flow s that detects earlier, detect the modulation coding mode coded data stream of high-order again, for example data flow t; Perhaps earlier high to transmitting power data flow, for example data flow s detects, and eliminates the interference of the data flow s that detects earlier in received signal, detects the low data flow of transmitting power again, for example data flow t.Because the interference of data flow s is eliminated, when utilizing the interference eliminated detection technique to detect t again, the CQI of data flow t is improved, so unified regulation for each terminal, all is that the CQI of data flow t is higher.Use each road signal flow of each transmission antennas transmit in the embodiment of the invention in turn, data flow t place channel is a transmitting antenna 1 at some symbol period, and is transmitting antennas 2 at other symbol periods.

If two data flow s and t in the present embodiment detect data flow s after also can stipulating to detect data flow t earlier, make data flow s have higher CQI; Embodiments of the invention are not limited to only two data streams be transmitted, and also can be the Channel Transmission of two above more data streams by the difference correspondence, at this moment are exactly the detection order of a plurality of data flow of unified regulation.

Use a certain transmission antennas transmit one circuit-switched data to flow signal at prior art is fixing usually, for example data flow s is fixing uses transmitting antenna 1, and the fixing transmitting antenna 2 that uses of data flow t.So at certain TTI that determines, for a plurality of receiving terminals under the MBS scene, usually all be for a part of receiving terminal wherein, the channel quality indication of transmitting antenna 1 is better than the channel quality indication of transmitting antenna 2, i.e. the channel quality of data flow s indication is better than the channel quality indication of data flow t; And for other a part of receiving terminal, the indication of the channel quality of transmitting antenna 2 is better than the channel quality indication of transmitting antenna 1, i.e. the channel quality of data flow t indication is better than the channel quality indication of data flow s.Thereby, a transmitting terminal under the MBS scene, which no matter adjust the MCS (modulation coding mode) of the data flow among data flow s and the t than higher, some receiving terminal of capital can not obtain receptivity preferably, for example, suppose that transmitting terminal adjusts than higher to the MCS of data flow s (modulation coding mode), this channel quality for transmitting antenna 1 indicates preferably that receiving terminal is suitable so, and indicate preferably receiving terminal and improper for the channel quality of transmitting antenna 2, thereby the channel quality of transmitting antenna 2 indicates preferably receiving terminal can not obtain receptivity preferably.

Therefore, the communication means of the mimo system that is used for Multimedia Broadcast Multicast Service that present embodiment provides, by using the different traffic spike of each transmission antennas transmit in turn, and the unified order of the receiver regulation of each terminal is carried out interference eliminated to different data flow detect, thereby guarantee for all receiving terminals, all be lower, and the CQI of the data flow detected than the back is than higher than the CQI of earlier detected data flow; Thereby again with among data flow s and the data flow t the detected CQI in back adjust than higher than the MCS (modulation coding mode) of higher data flow, for example data flow t is than higher, thereby can improve the performance of Channel Transmission, all receiving terminals all there is receptivity preferably, overcomes the fixing above-mentioned defective of using a certain transmission antennas transmit one circuit-switched data stream signal.

As shown in Figure 2, be the schematic flow sheet of the MIMO communication means embodiment two of Multimedia Broadcast Multicast Service of the present invention.Signal to two data flow has adopted the emission matrix of STBC diversity technique to launch in the present embodiment, specifically comprises the steps:

Step 201, set the detection order of each data flow;

For example two data flow s in the present embodiment and t, regulation detects data flow s earlier, detects data flow t again;

Step 202, according to the detection order that step 201 is set, the modulation coding mode or the transmitting power of each data flow is set;

For example, set in the present embodiment and detect data flow s earlier, data flow t is detected in the back.In order to guarantee that data flow t has the CQI higher than data flow s, must guarantee at first that data flow s can correctly be detected when follow-up receiver adopts interference cancellation techniques that data stream is detected.Have only the correct testing result of utilizing data flow s to eliminate the interference of s, when detecting data flow t, just can have higher SINR, thereby data flow t is detected correctly.Therefore, want to improve the probability of the correct detection of data flow s, data flow s will adopt the modulation coding mode than data flow t low order so, distributes higher power perhaps for data flow s;

Step 203, in Transmission Time Interval, adopt diversity antenna technology, use each traffic spike of the combined transmit independent channel coding of each transmitting antenna in turn;

The diversity antenna technology that adopts in the present embodiment carries out the circulation of transmitting antenna for adopting the space diversity method of STBC, sends 2 data flow of independent channel coding.For an application scenarios commonly used among the MBS be, there are 4 transmitting antennas the base station, the scene of the rarest 2 reception antennas of portable terminal, and corresponding emission matrix is:

$\left[\begin{array}{cccc}{t}_1& -t_2^{*}& s_3& -s_4^{*}\\ t_2& t_1^{*}& s_4& s_3^{*}\\ s_1& -s_2^{*}& t_3& -t_4^{*}\\ s_2& s_1^{*}& t_4& t_3^{*}\end{array}\right]$

Top emission matrix represents to adopt many patterns of code words, and promptly t represents an independent channel coded data stream, and s represents another one independent channel coded data stream.Above-mentioned each transmitting antenna of each line display, each symbol period is shown in each tabulation.Transmitting antenna wherein can be actual physical antenna, perhaps virtual-antenna.4 symbol periods that emission matrix comprises are corresponding to 2 kinds of situations: 1st, 2 symbol periods, the data flow t behind transmitting antenna 1, the 2 combined transmit coding, the data flow s behind transmitting antenna 3, the 4 combined transmit coding; 3rd, 4 symbol periods, the data flow s behind transmitting antenna 1, the 2 combined transmit coding, the data flow t behind transmitting antenna 3, the 4 combined transmit coding.Above-mentioned either way need be in a TTI traversal is repeatedly successively;

The detailed embodiment that a plurality of symbol periods in a TTI, transmitting terminal use above-mentioned emission matrix to transmit is: at the 1st symbol period of a TTI, 4 transmitting antennas are launched successively by 4 shown in the 1st row of emission matrix and are transmitted; At 2nd symbol period adjacent with described the 1st symbol period of this TTI, 4 transmitting antennas are launched successively by 4 shown in the 2nd row of emission matrix and are transmitted; At 3rd symbol period adjacent with described the 2nd symbol period of this TTI, 4 transmitting antennas are launched successively by 4 shown in the 3rd row of emission matrix and are transmitted; At 4th symbol period adjacent with described the 3rd symbol period of this TTI, 4 transmitting antennas are launched successively by 4 shown in the 4th row of emission matrix and are transmitted; So after 4 row of emission matrix all used, restart to use the 1st row of emission matrix again, begin new cyclic process, promptly this TTI with described the 1st, 2,3,4 symbol period in any one the 5th adjacent symbol period, 4 transmitting antennas are launched successively by 1 shown in the 1st row of emission matrix and are transmitted ...So, a plurality of symbol periods in a TTI all use each row of above-mentioned emission matrix to transmit successively in turn.

Each data flow of step 204, reception transmission antennas transmit;

Step 205, according to the detection order, detect earlier and adopt low-order-modulated coded system coded data stream; Perhaps detect the data flow of distributing high transmit power earlier;

One or more receivers in the present embodiment can adopt interference excision detection technology earlier data flow s to be detected, and eliminate the interference of data flow s;

Step 206, according to the detection order, detect to adopt high order modulation coded system coded data stream again; Perhaps detect the data flow of distributing low transmitting power again.

Because what adopt in the present embodiment is to use transmission antenna group to share Alamouti STBC emission matrix in turn to transmit, so data flow s can be regarded as identical with the channel that data flow t is experienced; Thereby under the situation of not considering the receiver interference cancellation gain, the CQI of data flow s and t is identical.So, the order of receiver interference eliminated has just determined the relative size of the CQI value of data flow s and data flow t.That is, at first eliminated the interference of data flow s in the present embodiment after, detect data flow t again, because the interference of data flow s eliminates, so data flow t has the CQI value higher than data flow s after after testing.So just can guarantee, for each terminal, all be that the CQI of data flow t is higher.Use each emitting antenna combination to launch each road signal flow in the embodiment of the invention in turn, data flow t place channel is that transmitting antenna 1 and 2 combinations send at some symbol period, and is that transmitting antenna 3 and 4 combinations send at other symbol periods.

Therefore, the communication means of the mimo system that is used for Multimedia Broadcast Multicast Service that present embodiment provides, adjust than higher by MCS (modulation coding mode) with the some data flow among data flow s and the data flow t, for example data flow t is than higher, for all receiving terminals, the CQI that is data flow t is than higher; Again in conjunction with using the different traffic spike of emitting antenna combination emission in turn, thereby can improve the performance of Channel Transmission, all receiving terminals all there is receptivity preferably, overcomes the fixing above-mentioned defective of using a certain emitting antenna combination to launch the traffic spike after one road Alamouti STBC encodes.

On the basis of the foregoing description two, the communication means of the mimo system that is used for Multimedia Broadcast Multicast Service that embodiments of the invention three provide can obtain the two better receptivities than embodiment.Emission matrix in the present embodiment is:

$\left[\begin{array}{cccccccccccccccccccccccc}{t}_1& -t_2^{*}& t_3& -t_4^{*}& t_5& -t_6^{*}& s_7& -s_8^{*}& s_9& -s_{10}^{*}& s_{11}& -{\mathrm{<figure-callout\; id="12"\; label="s"\; filenames="S2008101024436E00022.png"\; state="\{\{state\}\}">s</figure-callout>}}_{12}^{*}& s_{13}& -{\mathrm{<figure-callout\; id="14"\; label="s"\; filenames="S2008101024436E00022.png"\; state="\{\{state\}\}">s</figure-callout>}}_{14}^{*}& s_{15}& -s_{16}^{*}& s_{17}& -s_{18}^{*}& t_{19}& -t_{20}^{*}& t_{21}& -{\mathrm{<figure-callout\; id="22"\; label="t"\; filenames="S2008101024436E00022.png"\; state="\{\{state\}\}">t</figure-callout>}}_{22}^{*}& t_{23}& -t_{24}^{*}\\ t_2& t_1^{*}& s_3& s_4^{*}& s_5& -s_6^{*}& s_8& s_7^{*}& t_9& t_{10}^{*}& t_{11}& {\mathrm{<figure-callout\; id="12"\; label="t"\; filenames="S2008101024436E00022.png"\; state="\{\{state\}\}">t</figure-callout>}}_{12}^{*}& s_{14}& {\mathrm{<figure-callout\; id="13"\; label="s"\; filenames="S2008101024436E00022.png"\; state="\{\{state\}\}">s</figure-callout>}}_{13}^{*}& t_{15}& t_{16}^{*}& t_{17}& -t_{18}^{*}& t_{19}& t_{20}^{*}& s_{21}& {\mathrm{<figure-callout\; id="22"\; label="s"\; filenames="S2008101024436E00022.png"\; state="\{\{state\}\}">s</figure-callout>}}_{22}^{*}& s_{23}& s_{24}^{*}\\ s_1& -s_2^{*}& t_4& t_3^{*}& s_6& s_5^{*}& t_7& t_8^{*}& s_{10}& s_9^{*}& t_{12}& -{\mathrm{<figure-callout\; id="11"\; label="t"\; filenames="S2008101024436E00022.png"\; state="\{\{state\}\}">t</figure-callout>}}_{11}^{*}& t_{13}& -{\mathrm{<figure-callout\; id="14"\; label="t"\; filenames="S2008101024436E00022.png"\; state="\{\{state\}\}">t</figure-callout>}}_{14}^{*}& s_{16}& s_{15}^{*}& t_{18}& t_{17}^{*}& s_{19}& s_{20}^{*}& t_{22}& {\mathrm{<figure-callout\; id="21"\; label="t"\; filenames="S2008101024436E00022.png"\; state="\{\{state\}\}">t</figure-callout>}}_{21}^{*}& s_{24}& -s_{23}^{*}\\ s_2& s_1^{*}& s_4& -s_3^{*}& t_6& t_5^{*}& t_8& -t_7^{*}& t_9& -t_{10}^{*}& s_{12}& {\mathrm{<figure-callout\; id="11"\; label="s"\; filenames="S2008101024436E00022.png"\; state="\{\{state\}\}">s</figure-callout>}}_{11}^{*}& t_{14}& {\mathrm{<figure-callout\; id="13"\; label="t"\; filenames="S2008101024436E00022.png"\; state="\{\{state\}\}">t</figure-callout>}}_{13}^{*}& t_{16}& -t_{15}^{*}& s_2& s_{18}^{*}& s_{20}& -s_{19}^{*}& s_{22}& -{\mathrm{<figure-callout\; id="21"\; label="s"\; filenames="S2008101024436E00022.png"\; state="\{\{state\}\}">s</figure-callout>}}_{21}^{*}& t_{24}& t_{23}^{*}\end{array}\right]$

This emission matrix adopts many code words usually, and promptly t represents an independent channel coded data stream, and s represents another one independent channel coded data stream.And 24 above-mentioned symbol periods corresponding to 12 kinds of situations, all need travel through in a TTI.Utilize principle: between each TTI, data flow s and data flow t are less in the fluctuation ratio of the instantaneous channel capacity of each TTI, the above-mentioned emission matrix of design can further reduce data flow s and the data flow t fluctuation in the instantaneous channel capacity (being TTI) of each TTI.And the optimal ordering that travels through above-mentioned emission matrix (promptly, reach optimally diversified effect), by emulation as can be known, an optimal ordering can taking is (with 1,2,, 12 represent top 12 kinds of corresponding situations of 24 row successively, a kind of situation is shown in adjacent 2 tabulations): 1,7,2,8,3,9,4,10,5,11,6,12.

Now as follows: as to suppose to comprise in 1 TTI 108 symbol periods for a more detailed embodiment, so, 24 symbol periods of head adjacent successively in 1 TTI use above-mentioned emission matrix 1 time according to above-mentioned optimal ordering, and use above-mentioned emission matrix 1 time at 24 next adjacent successively symbol periods according to above-mentioned optimal ordering then, so circulate repeatedly (here being 4 times), up to 24 of remaining symbol period number deficiency (here being 12); In the symbol period of 24 of described remaining adjacent successively less thaies, (be made as X) then, use the X row in 24 row of emission matrix to transmit according to above-mentioned optimal ordering.

The communication means of the mimo system that is used for Multimedia Broadcast Multicast Service that present embodiment provides, by utilizing between each TTI, data flow s and data flow t are in less this principle of the fluctuation ratio of the instantaneous channel capacity of each TTI, MBS business for normally open loop, can obtain better channel gain and receptivity, reduce the Packet Error Ratio in the message transmission.

The communication means of the mimo system that is used for Multimedia Broadcast Multicast Service that the embodiment of the invention four provides does not use the Space-Time Block Coding coded system to transmit obtaining space diversity gain, but the coded system that adopts other is to obtain space diversity gain.Such as: for the ofdm communication system that chnnel coding is arranged, exist a kind of time delay deversity scheme (Cyclic Shift Diversity, hereinafter to be referred as: CSD).

For the base station 4 transmitting antennas are arranged, the MBS scene of the rarest 2 reception antennas of portable terminal, corresponding launch scenario is: tentation data stream t and data flow s adopt the CSD deversity scheme, assign to two transmitting antennas respectively and get on to transmit.Wherein, data flow t adopts the CSD deversity scheme, and being assigned to the data flow of launching on two transmitting antennas is t _a, t _b, and data flow s adopts the CSD deversity scheme, being assigned to the data flow of launching on two transmitting antennas is s _a, s _b, a so corresponding emission matrix is:

$\left[\begin{array}{cc}{t}_a^1& s_a^2\\ t_b^1& s_b^2\\ s_a^1& t_a^2\\ s_b^1& t_b^2\end{array}\right]$

Wherein, first symbol and second symbol of 1,2 expression data flow t of the subscript on the data flow and data flow s.

Identical with previous embodiment, for example unified each receiving terminal of stipulating detects data flow s earlier, eliminates the interference of data flow s, detects data flow t again.Thereby data flow t adopts different MCS (modulation coding mode) with data flow s, distribute the scheme of different power to be perhaps for data flow t and data flow s: data flow s adopts the MCS of lower-order, distribute higher power perhaps for data flow s, to improve the probability that data flow s is correctly detected.Adopt unified each receiving terminal of stipulating that the concrete reason and the beneficial effect of the detection order of data flow are illustrated in the aforementioned embodiment.

In this CSD deversity scheme, adopt the unification of the embodiment of the invention to stipulate in the method for each receiving terminal to the detection order of data flow, because the reason of two shared pilot tones of transmitting antenna of CSD, the combination that CSD sends out two used antennas of symbol is not suitable for any variation, but be fixed as combination of antennas 1 and 2 CSD, and combination of antennas 3 and 4 another CSD.This specific character causes it to obtain does not have antenna diversity scheme good on the receptivity, but can improve the yield value and the receptivity of signal channel yet.

The communication means of the mimo system that is used for Multimedia Broadcast Multicast Service that the embodiment of the invention five provides, do not use the Space-Time Block Coding coded system to transmit equally to obtain space diversity gain, use each antenna simply in turn but adopt, to reach the effect of diversity, the signal emission matrix of this embodiment is as follows:

$\left[\begin{array}{cccccccccccc}{t}_1& 0& 0& t_4& t_5& 0& s_7& 0& 0& s_{10}& s_{11}& 0\\ s_1& 0& t_3& 0& 0& t_6& t_7& 0& s_9& 0& 0& s_{12}\\ 0& t_2& s_3& 0& s_5& 0& 0& s_8& t_9& 0& {\mathrm{<figure-callout\; id="11"\; label="t"\; filenames="S2008101024436E00022.png"\; state="\{\{state\}\}">t</figure-callout>}}_{11}& 0\\ 0& s_2& 0& s_4& 0& s_6& 0& t_8& 0& t_{10}& 0& {\mathrm{<figure-callout\; id="12"\; label="t"\; filenames="S2008101024436E00022.png"\; state="\{\{state\}\}">t</figure-callout>}}_{12}\end{array}\right]$

This emission matrix represents to adopt usually many code words, and promptly t represents an independent channel coded data stream, and s represents another one independent channel coded data stream.Wherein, the from the 7th to the 12nd symbol period launched two combination of antennas that symbol is used, just in time is the combination of antennas that repeats the 1st to the 6th symbol period successively, and just the corresponding relation of two antennas of data flow t, s and combination of antennas has become.And 12 above-mentioned symbol periods corresponding to 12 kinds of situations, all need travel through in a TTI, and the optimal ordering of traversal needs emulation to determine.Experiment shows, as long as can guarantee that s and the approximately equalised traversal order of the CQI of t under the situation of not considering interference eliminated can.But the fluctuation in the instantaneous CQI of different TTI may be big a little.

Accordingly,, detect data flow s earlier, eliminate the interference of data flow s, detect data flow t again as unified each terminal that is defined as the above embodiments.Thereby data flow t adopts different MCS modes with data flow s, distribute the scheme of different power to be perhaps for data flow t and data flow s: data flow s adopts the MCS of lower-order, distribute higher transmitting power perhaps for data flow s, to improve the probability that data flow s is correctly detected.

Therefore, the communication means of the mimo system that is used for Multimedia Broadcast Multicast Service that present embodiment provides, adjust than higher by MCS (modulation coding mode) with the some data flow among data flow s and the data flow t, for example data flow t is than higher, for all receiving terminals, the CQI that is data flow t is than higher; The different traffic spike of transmission antennas transmit is used in combination in turn again, thereby can improve the performance of Channel Transmission, and all receiving terminals are all had receptivity preferably.

The communication means of the mimo system that is used for Multimedia Broadcast Multicast Service that the embodiment of the invention six provides, as shown in Figure 3, can also be in the above-described embodiments, receiving terminal also comprises after adopting unified regulation to finish detection to data flow in proper order:

Step 301, feedback are dynamically adjusted the result to each transmitting antenna;

Should dynamically adjust the difference of the high modulation order of modulation coding mode that the result adopts for the data flow that increases or reduce the data flow that detects earlier and back and detect, perhaps for increasing or reduce the difference of the data stream transmission performance number that the data flow that detects earlier and back detects;

Step 302, each transmitting antenna are dynamically adjusted the modulation coding mode or the transmitting power of the data flow that detects earlier.

A scheme should dynamically adjusting be: all at interval or whenever several TTI are at interval at each TTI for each receiving terminal, feedback wishes to increase the order of MCS or the difference of transmission power level, still reduce the difference of order or the transmission power level of MCS, and the feedback of comprehensive each receiving terminal of transmitting base station BS, decide thereafter one or several TTI to increase the order of MCS or the difference of transmission power level, still reduce the difference of order or the transmission power level of MCS, and the amount that increases or reduce is that receiving-transmitting sides is appointed at every turn.The design of feedback channel, can be: do energy statistics by the base station, each terminal is under identical running time-frequency resource, the feedback signaling (sending out) of the order of transmission increase MCS or the difference of transmission power level with identical spreading code, terminal use's quantity of difference is wished to increase by the signal strength signal intensity of statistics on this running time-frequency resource in the base station with estimation; Same method can also be used to estimating the terminal use's who wishes the minimizing difference quantity, and comprehensively the two makes decision last BS, promptly increases difference and still reduces difference.

More than cited various embodiments of the present invention, all be at such scene: each receiving terminal of Multimedia Broadcast Multicast Service is minimum to have 2 reception antennas, thus 2 independent channel coded datas streams of transmitting terminal emission.And the minimum reception antenna number of each receiving terminal of Multimedia Broadcast Multicast Service may increase, and respective embodiments is as described below.

The embodiment seven of the MIMO communication means of Multimedia Broadcast Multicast Service, there are 4 transmitting antennas the base station, and the scene of the rarest 3 reception antennas of each portable terminal of Multimedia Broadcast Multicast Service.For the similar scene of clean culture, in being 200710004560 patent application " multi-antenna communication method and system ", application number provides, for transmitting terminal 4 transmitting antennas are arranged, and the scene of the dimension K of spatial reuse=3 has provided following signal emission form:

$\left[\begin{array}{cccc}{s}_i& s_{i+1}& t_i& t_{i+1}\\ -s_{i+1}^{*}& s_i^{*}& t_{i+2}& t_{i+3}\\ s_{i+2}& t_{i+4}& s_{i+3}& t_{i+5}\\ -s_{i+3}^{*}& t_{i+6}& s_{i+2}^{*}& t_{i+7}\\ s_{i+4}& t_{i+8}& t_{i+9}& s_{i+5}\\ -s_{i+5}^{*}& t_{i+10}& t_{i+11}& s_{i+4}^{*}\\ t_{i+12}& s_{i+7}& s_{i+6}& t_{i+13}\\ t_{i+14}& s_{i+6}^{*}& -s_{i+7}^{*}& t_{i+15}\\ t_{i+16}& t_{i+17}& s_{i+8}& s_{i+9}\\ t_{i+18}& t_{i+19}& -s_{i+9}^{*}& s_{i+8}^{*}\\ t_{i+20}& s_{i+10}& t_{i+21}& s_{i+11}\\ t_{i+22}& -s_{i+11}^{*}& t_{i+23}& s_{i+10}^{*}\end{array}\right]$

In the top emission matrix, 4 row are represented each transmitting antenna respectively, and each row is represented each symbol period respectively, slightly different with the expression way of the various embodiments described above, the emission form of above-mentioned signal both can be used for closed loop, also can be used for open loop, the condition of its enforcement is: this mimo system transmitting terminal has M transmission antennas transmit K road (K is less than M) data flow.

This embodiment seven can further be optimized by the order of adjusting each row of emission matrix.

$C_1=\left[\begin{array}{cccc}{s}_1& -s_2^{*}& s_7& s_{11}\\ s_2& s_1^{*}& s_8& s_{12}\\ s_3& s_5& s_9& -s_{10}^{*}\\ s_4& s_6& s_{10}& s_9^{*}\end{array}\right],$ $C_2=\left[\begin{array}{cccc}{s}_1& -s_3^{*}& s_7& s_{11}\\ s_2& s_5& s_8& -s_{10}^{*}\\ s_3& s_1^{*}& s_9& s_{12}\\ s_4& s_6& s_{10}& s_8^{*}\end{array}\right],$ $C_3=\left[\begin{array}{cccc}{s}_1& -s_4^{*}& s_7& s_{11}\\ s_2& s_5& s_8& -s_{10}^{*}\\ s_3& s_6& s_9& s_9^{*}\\ s_4& s_1^{*}& s_{10}& s_{12}\end{array}\right]$

In above-mentioned each emission matrix, transmitting antenna of each line display, and a symbol period is shown in each tabulation.Above-mentioned each emission matrix is used for transmitting terminal 4 transmitting antennas, and the reception antenna number of receiving terminal is no less than in 3 the unicast system, and, in a plurality of symbol periods of a TTI, use 3 above-mentioned emission matrix C successively in turn ₁, C ₂And C ₃, concrete mode is: in each 12 the adjacent successively symbol period in 1 TTI, according to the order of each row in each emission matrix, use emission matrix C successively ₁4 row, C ₂4 row and C ₃4 row each 1 time.Be characterized in: C ₁, C ₂And C ₃All satisfy 2 symbol periods in end and launch one group of used 2 symbol period of two transmitting antennas and head of Alamouti Space-Time Block Coding to launch two used transmitting antennas of one group of Alamouti Space-Time Block Coding different fully, for example at C ₁In, first 2 symbol periods are launched the antenna 1 and 2 that one group of Alamouti Space-Time Block Coding uses, and the antenna 3 and 4 of launching one group of Alamouti Space-Time Block Coding use with 2 symbol periods in end is different fully, and promptly used antenna neither one is identical.Thus, at C ₁, C ₂And C ₃In 4 the adjacent successively symbol periods that take respectively, the used two groups of antennas of Fa She two groups of Alamouti Space-Time Block Codings are different fully successively, can reach better diversity gain thus.

The foregoing description seven that is used for clean culture also can be generalized to the multicast that comprises base station and a plurality of receiving terminals and the application scenarios of broadcasting service.

The embodiment eight of the MIMO communication means of Multimedia Broadcast Multicast Service, there are 4 transmitting antennas the base station, and the scene of the rarest 4 reception antennas of each portable terminal of Multimedia Broadcast Multicast Service.For the similar scene of clean culture, in application number is 200710000610 patent application " MIMO multi-code communication method ", two embodiment have been provided, that is:

One is, for the base station 4 transmitting antennas is arranged, and the clean culture scene of the rarest 4 reception antennas of receiving terminal, and the used emission matrix of the method for the 12 kinds of arrangements of employing that provide is as follows:

Wherein, a, b, c, d represent 4 tunnel data flow of absolute coding separately respectively, and this 4 circuit-switched data is detected according to the sequencing of a, b, c, d;

Another one is, for above-mentioned clean culture scene, also has the method for 24 kinds of arrangements of a kind of employing, and used emission matrix is as follows:

Wherein, a, b, c, d in the emission matrix in the emission matrix of the implication of a, b, c, d and above-mentioned 12 kinds of arrangements are identical, and in each symbol period of a TTI, transmitting terminal uses each row of above-mentioned emission matrix to transmit successively.

Above-mentioned two embodiment at clean culture are generalized in the multicast and broadcasting service of present embodiment eight, there are 4 transmitting antennas the base station, and the rarest 4 reception antennas of each portable terminal of Multimedia Broadcast Multicast Service, each symbol period at a TTI, the base station uses in following two emission matrix any one to transmit, that is:

Perhaps

$\left[\begin{array}{cccc}a& c& d& b\\ b& d& c& a\\ c& b& a& d\\ d& a& b& c\end{array}\right]\left[\begin{array}{cccc}a& c& d& b\\ c& b& a& d\\ b& d& c& a\\ d& a& b& c\end{array}\right]\left[\begin{array}{cccc}a& b& c& d\\ c& d& b& a\\ d& c& a& b\\ b& a& d& c\end{array}\right]\left[\begin{array}{cccc}c& a& d& b\\ d& b& c& a\\ a& d& b& c\\ b& c& a& d\end{array}\right]\left[\begin{array}{cccc}a& c& d& b\\ d& a& b& c\\ b& d& c& a\\ c& b& a& d\end{array}\right]\left[\begin{array}{cccc}a& c& d& b\\ d& a& b& c\\ c& b& a& d\\ b& d& c& a\end{array}\right]$

Wherein, a, b, c, d represent 4 tunnel data flow of absolute coding separately respectively, and this 4 circuit-switched data is detected according to the sequencing of a, b, c, d, be that receiving terminal at first detects a and eliminates the interference of a, the interference that next detects b and eliminates b, secondly detect c again and eliminate the interference of c, detect d at last.And data flow a, b, c, d adopt more high-order or constant MCS successively, and perhaps data flow a, b, c, d adopt lower or constant transmitting power successively; Simultaneously, at least one data flow adopts than the another one data flow MCS of high-order more among data flow a, b, c, the d, and perhaps at least one data flow adopts the transmitting power lower than another one data flow among data flow a, b, c, the d.

As shown in Figure 4, be the structural representation of the MIMO communication system embodiment of Multimedia Broadcast Multicast Service of the present invention.The MIMO communication system of this Multimedia Broadcast Multicast Service comprises: transmitter 1, be used for using in turn each traffic spike of at least two transmission antennas transmit independent channel codings, wherein, at least one data flow adopts the modulation coding mode than other data flow high-order, perhaps is lower than other data flow for the transmitting power of at least one distribution of flows; Described transmitting antenna can be physical antenna or virtual-antenna.A plurality of receivers are used to receive each data flow of transmission antennas transmit, and the situation of a receiver 2 only is shown among Fig. 4.

Wherein, in a transmitter 1 shown in Figure 4 and receiver 2, transmitter 1 comprises: detection is provided with module 11 in proper order, is used to set the detection order of each data flow of the independent channel coding that 2 pairs of receivers will receive; Antenna traversal is provided with module 12, is used to be provided with the traversal order that transmitting antenna or emitting antenna combination transmit.Also comprise: modulating-coding module 13, be used for the detection order of module 11 settings or the dynamic adjustment result of feedback being set in proper order according to detection, the modulation coding mode of data flow is set; And/or power setting module 14, be used for the detection order of module 11 settings or the dynamic adjustment result of feedback being set in proper order according to detection, the transmitting power of data flow is set.

Receiver 2 comprises: detection module 21, be used for the detection order that module 11 is set being set in proper order according to detection, and detect earlier and adopt low-order-modulated coded system coded data stream, detect again and adopt high order modulation coded system coded data stream; Perhaps detect the data flow of distributing high transmit power earlier, detect the data flow of distributing low transmitting power again; Feedback module 22 is used to feed back modulating-coding module 13 or the power setting module 14 of dynamic adjustment result to each transmitter 2, dynamically adjusts the result and is the data flow and the modulation coding mode of the data flow of back detection or the difference of power that increase or minimizing detects earlier.

It should be noted that at last: above embodiment only in order to technical scheme of the present invention to be described, is not intended to limit; Although with reference to previous embodiment the present invention is had been described in detail, those of ordinary skill in the art is to be understood that: it still can be made amendment to the technical scheme that aforementioned each embodiment put down in writing, and perhaps part technical characterictic wherein is equal to replacement; And these modifications or replacement do not make the essence of appropriate technical solution break away from the spirit and scope of various embodiments of the present invention technical scheme.

Claims (14)

1. the MIMO communication means of a Multimedia Broadcast Multicast Service is characterized in that comprising:

Use each traffic spike of at least two transmission antennas transmit independent channel codings in turn, wherein, at least one described data flow adopts the modulation coding mode than other data flow high-order, perhaps is lower than other data flow for the transmitting power of at least one described distribution of flows;

Receive described each data flow of described transmission antennas transmit.

2. the MIMO communication means of Multimedia Broadcast Multicast Service according to claim 1 is characterized in that described transmitting antenna is: physical antenna, perhaps virtual-antenna.

3. the MIMO communication means of Multimedia Broadcast Multicast Service according to claim 2 is characterized in that described each traffic spike of at least two transmission antennas transmit independent channels codings that uses in turn specifically comprises:

In Transmission Time Interval, use each traffic spike of each transmission antennas transmit independent channel coding in turn; Perhaps,

In Transmission Time Interval, adopt diversity technique, use each traffic spike of the combined transmit independent channel coding of each transmitting antenna.

4. the MIMO communication means of Multimedia Broadcast Multicast Service according to claim 3 is characterized in that described employing diversity technique is: the antenna collection method that adopts Space-Time Block Coding; Perhaps, adopt the time delay deversity scheme.

5. according to the MIMO communication means of claim 1,2,3 or 4 described Multimedia Broadcast Multicast Service, it is characterized in that before described each traffic spike that uses at least two transmission antennas transmit independent channels to encode in turn, also comprising: the detection order of setting described each data flow.

6. the MIMO communication means of Multimedia Broadcast Multicast Service according to claim 5 is characterized in that comprising after described each data flow of the described transmission antennas transmit of described reception:

According to described detection order, detect earlier and adopt low-order-modulated coded system coded data stream, detect again and adopt high order modulation coded system coded data stream; Perhaps,

According to described detection order, detect the data flow of distributing high transmit power earlier, detect the data flow of distributing low transmitting power again.

7. the MIMO communication means of Multimedia Broadcast Multicast Service according to claim 6, it is characterized in that at least one receiving terminal adopts interference excision detection technology that described data flow is detected, in the received signal of described receiving terminal, according to described detection order, eliminate the interference of the data flow that detects earlier, detect other data flow again.

8. the MIMO communication means of Multimedia Broadcast Multicast Service according to claim 6 is characterized in that also comprising after according to described detection sequence detection data flow:

Feedback is dynamically adjusted the result to each transmitting antenna, the difference of the high modulation order of the modulation coding mode that described dynamic adjustment result adopts for the data flow that increases or reduce the data flow that detects earlier and back and detect is perhaps for increasing or reduce the difference of the data stream transmission performance number that the data flow that detects earlier and back detects;

Each transmitting antenna is dynamically adjusted the described modulation coding mode or the described transmitting power of the data flow that detects earlier.

9. the MIMO communication system of a Multimedia Broadcast Multicast Service is characterized in that comprising:

Transmitter, be used for using in turn each traffic spike of at least two transmission antennas transmit independent channel codings, wherein, at least one described data flow adopts the modulation coding mode than other data flow high-order, perhaps is lower than other data flow for the transmitting power of at least one described distribution of flows;

A plurality of receivers are used to receive described each data flow of described transmission antennas transmit.

10. the MIMO communication system of Multimedia Broadcast Multicast Service according to claim 9 is characterized in that described transmitting antenna is: physical antenna, perhaps virtual-antenna.

11. according to the MIMO communication system of claim 9 or 10 described Multimedia Broadcast Multicast Service, it is characterized in that described transmitter comprises: detection is provided with module in proper order, is used to set the detection order of described each data flow.

12. the MIMO communication system of Multimedia Broadcast Multicast Service according to claim 11 is characterized in that described transmitter also comprises: antenna traversal is provided with module, is used to be provided with the traversal order that transmitting antenna or emitting antenna combination transmit.

13. the MIMO communication system of Multimedia Broadcast Multicast Service according to claim 12 is characterized in that described transmitter also comprises:

The modulating-coding module is used to be provided with the modulation coding mode of described data flow; And/or,

The power setting module is used to be provided with the transmitting power of described data flow.

14. the MIMO communication system of Multimedia Broadcast Multicast Service according to claim 13 is characterized in that described receiver comprises:

Detection module is used for detecting earlier and adopting low-order-modulated coded system coded data stream according to described detection order, detects and adopts high order modulation coded system coded data stream; Perhaps detect the data flow of distributing high transmit power earlier, detect the data flow of distributing low transmitting power again;

Feedback module, be used to feed back modulating-coding module or the power setting module of dynamic adjustment result to each described transmitter, the difference of the high modulation order of the modulation coding mode that described dynamic adjustment result adopts for the data flow that increases or reduce the data flow that detects earlier and back and detect is perhaps for increasing or reduce the difference of the data stream transmission performance number that the data flow that detects earlier and back detects.

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