CN102447522A - Multilayer transmission method and device - Google Patents

Abstract

The invention provides a multilayer transmission method and device. The invention provides a communication method which comprises the following steps of: receiving a channel quality indicator; and selecting a modulation and encoding scheme for code words at least partially based on the channel quality indicator, wherein a code word is mapped to at least one layer; the code word uses a same code rate at all the layers where the code word is mapped to, but can use a same modulation scheme or different modulation schemes at each layer according to the quality of the channel. The invention also provides a corresponding device.

Description

The method and apparatus of multilayer transmission

Technical field

Exemplary non-limiting execution mode of the present invention relates generally to wireless communication system, method, equipment and computer program, more specifically, relates to the modulation and the encoding scheme (MCS) of multilayer transmission.

Background technology

(Long Term Evolution, LTE) target of technology is to realize higher data rate, shorter time delay, lower cost, higher power system capacity and improved coverage to the 3GPP Long Term Evolution.LTE-Advanced (LTE-A) technology is the follow-up evolution of LTE.Multiple-input and multiple-output (MIMO) technology is the key technology of LTE and LTE-A system intermediate frequency spectrum improved efficiency.

In mimo wireless communication system, transmitter and receiver all use aerial array, thereby abundant Fen Ji and big message capacity are provided.Spatial reuse is a modulation technique when being used for MIMO communication system common empty, wherein through distinct transmit antenna transmission independent data stream.The downlink transmission process of LTE/LTE-A can comprise following a few step: the data to from the upper strata are carried out chnnel coding and modulation, to form code word; Different code word is carried out layer mapping; Data to after the layer mapping are carried out precoding, send to be mapped on the antenna.

(Code Words CW) is meant that the Business Stream from the upper strata carries out chnnel coding and modulation data afterwards to code word.At transmitting terminal, corresponding a MAC layer passes to the independent information piece of physical layer, and CRC protects through piece.At present, transmission block can be divided into one or more code words.A code word adopts identical modulation and encoding scheme (MCS), is mapped to one or more layers through layer mapping.Basically, corresponding spatial multiplexing passage of one deck.The number of plies equals the degree of freedom of mimo channel matrix, is also referred to as the order (rank) of mimo system.Layer mapping provides the demultiplexing to code word, is about to each code word and is demultiplexed into one or more layers.Therefore, the number of code word generally is no more than the number of plies.

Data for after the layer mapping are mapped to it on different antennas through pre-coding matrix, also are on the transmit antenna of physics.The number of plies generally is no more than the transmit antenna number.The effect of precoding is according to channel conditions, and data flow to be sent is carried out preliminary treatment, and data flow is mapped on the corresponding transmitting antenna.In LTE and LTE-A system, adopt such as precoding technique based on singular value decomposition (SVD).

When a code word being mapped to a plurality of layers of last time, adopt precoding can have very big variation for a plurality of layers the singular value of shining upon corresponding to this code word based on SVD and so on.In other words, through after the precoding, there is very big-difference in the capacity of each layer, and performance also is not quite similar.Therefore, this causes being difficult between the multilayer that a code word shines upon shares identical MCS, especially under the relatively large situation of the number of plies.

For example, adopt a code word and two-layer precoding as an example, system-level emulation shows than the individual layer precoding, can obtain 30% throughput gain at transmitting terminal.Yet, because to inappropriate MCS selection between each layer of a code word, in fact only less than 5% throughput gain.

For the capacity volume variance problem between the multilayer, a solution is every layer of only code word.Yet, considering implementation complexity (for example, the quantity of Turbo decoder) and chnnel coding gain (length of code word is short, and coding efficiency is low), the LTE/LTE-A system supports two code words at the most, even exist at the most under 8 layers the situation.And because every layer of code word only adopts too many code word like this, up/downlink signaling expense also is a problem.

In current LTE-A standardized process, to the MCS technology of multilayer transmission still discuss with research in.Up to now, when being mapped to a plurality of layers, how to select suitable MCS, corresponding solution is not provided as yet for a code word.

Summary of the invention

In view of this, execution mode of the present invention provides a code word and has been mapped under the situation of at least one layer, confirms the modulation of each layer and the method and apparatus of encoding scheme.

According to an illustrative aspects of the present invention, a kind of communication means is provided.This method comprises: the indication of receive channel quality; And part is indicated based on said channel quality at least; For code word is selected modulation and encoding scheme; One of them code word is mapped at least one layer; Said code word still can be used identical or different modulation schemes according to channel quality at each layer in the identical code rate of all layers use of being shone upon.

In one embodiment, the channel quality indication comprises and modulation scheme of said each layer and the relevant information of code rate of said all layers.

In another illustrative aspects of the present invention, a kind of communication means is provided.This method comprises: for each code word generates the channel quality indication when selecting modulation and encoding scheme, to use; One of them code word is mapped at least one layer; Said code word still can be used identical or different modulation schemes based on channel instruction at each layer in the identical code rate of all layers use of being shone upon; And send said channel quality and indicate.

In one embodiment, the channel quality indication comprises and modulation scheme of said each layer and the relevant information of code rate of said all layers.

In one embodiment, generating the channel quality indication comprises: calculate the modulation scheme of being distributed independently to said each layer; To all layers, select to satisfy the code rate r of the highest code rate of following formula as all layers ^h:

$r^h\·\underset{l=1}{\overset{L}{\mathrm{\Σ}}}\frac{s_l}{r_l}\≤1,$

Wherein

r ^hBe code rate to all layers, B ^hIt is the information bit of the code word on all layers; r _lBe the code rate of l layer when hypothesis adopts every layer of code word scheme, B _lIt is the information bit of the code word on the l layer when hypothesis adopts every layer of code word scheme; Function f (x, y) expression when code rate be x, when code length is y, the ratio of the bit error rate of information bit and the bit error rate of coded-bit; L is the number of plies that code word is shone upon, l=1 ..., L.

In one embodiment, calculate s by following formula _l:

M wherein _lBeing the modulation bit number of l layer, for example, is 2 bits for QPSK, is 4 bits for 16QAM, is 6 bits for 64QAM.

In another illustrative aspects of the present invention, a kind of communicator is provided.This communicator comprises: receiving system is used for the indication of receive channel quality; And choice device; Be used at least partly based on said channel quality indication; For code word is selected modulation and encoding scheme; One of them code word is mapped at least one layer, and said code word still can be used identical or different modulation scheme according to channel quality at each layer in the identical code rate of all layers use of being shone upon.

In an illustrative aspects more of the present invention, a kind of communicator is provided.This communicator comprises: channel quality indication generating apparatus; Be used to each code word and generate the channel quality indication when selecting modulation and encoding scheme, to use; One of them code word is mapped at least one layer; Said code word still can be used identical or different modulation scheme according to channel quality at each layer in the identical code rate of all layers use of being shone upon; And dispensing device, be used to send said channel quality indication.

Other aspects of the present invention can also comprise the computer program of carrying out said method and the storage medium that is used to store this program.

Execution mode of the present invention is mapped under the situation of at least one layer a code word, and the scheme of confirming suitable MCS for each layer is provided.

According to execution mode of the present invention, each layer that code word is shone upon can keep selecting modulation separately according to channel quality under the identical situation of code rate, and these modulation can be the same or different.Thereby than the scheme of the MCS of each code word of prior art, execution mode of the present invention can adapt to the characteristics such as capacity of each layer better.In addition, to this mixing MCS scheme, execution mode of the present invention also provides the CQI feedback mechanism.Designed a kind of new CQI/MCS, it comprises modulation of each layer of code word and unified code rate.Through this CQI feedback mechanism, can feed back CQI exactly, can practice thrift up signaling consumption again.In addition, the technical scheme of the present invention that is proposed is easy to implement, need not available frame is made big change.

Description of drawings

When combining advantages, in the detailed description hereinafter, above-mentioned and other aspects of embodiment of the present invention will become and know more and easy to understand, wherein:

Fig. 1 shows the example of the wireless communication system environments that the present invention can implement therein;

Fig. 2 shows the sketch map of the downlink transmission of prior art;

Fig. 3 shows the schematic logical flow chart according to the method for one embodiment of the present invention;

Fig. 4 shows the exemplary block diagram according to the device of the base station eNB side of an embodiment of the invention; And

Fig. 5 shows the exemplary block diagram according to the user terminal UE side of one embodiment of the present invention.

In all above-mentioned accompanying drawings, identical label representes to have identical, similar or corresponding feature or function.

Embodiment

The inventor recognizes that though a code word requires to adopt identical modulation and encoding scheme MCS, it only requires that in fact code rate is identical, and to not restriction of modulation scheme.Therefore; In view of this; Basic thought of the present invention is: when a code word is mapped to a plurality of layers; Can for this code word in the identical code rate of all layers employing that is mapped to, but can use modulation scheme separately according to channel quality at each layer, these modulation schemes can be identical or different.

Carry out detailed exemplary description below in conjunction with the accompanying drawing specific embodiments of the invention.

With reference to figure 1, it shows the example of the wireless communication network environments 100 that embodiment of the present invention can implement therein.As shown in Figure 1, this wireless communication network environments 100 can comprise base station BS 101 and some user equipment (UE) 102-1,102-2 ... 102-L, L are the integer more than or equal to 1.Base station BS 101 has M dual-mode antenna, each user equipment (UE) 102-1,102-2 ..., 102-L has N dual-mode antenna, wherein M and N are all greater than 1.In various execution modes, base station BS 101 is also referred to as eNB in LTE and LTE-A system.In the following description, various embodiments adopt base station eNB and user equipment (UE) to carry out exemplary description.

Fig. 2 shows the sketch map of the downlink transmission of prior art.As shown in Figure 2, transmission block TB is divided into several code words.Only show two code word CW1 and CW2 among Fig. 2, but it will be understood by those skilled in the art that the code word that can also be divided into other numbers.

Each code word has its independently chnnel coding and modulation.For example, code word CW1 channel encoder 201-1 carries out chnnel coding, modulates through modulator 202-1 then.Similarly, code word CW2 channel encoder 201-2 carries out chnnel coding, and 202-2 modulates through modulator.

Resulting data are mapped to each space layer in layer mapper 203.For example, when having two code word CW1, CW2 and four layer Layer0, Layer1, Layer2 and Layer3, can code word CW1 be mapped to Layer0 and Layer1, and code word CW2 is mapped to Layer2 and Layer3.It will be understood by those skilled in the art that above-mentioned example only is schematically, can also envision other layers mapping situation, for example, number of codewords is different, the asynchronous various layer mapping scheme of the number of plies.

Data for after the layer mapping are mapped to it on different antennas 205 through pre-coding matrix 204, also are on the transmit antenna of physics.

It will be understood by those skilled in the art that above-mentioned diagram only is schematically, can also there be a lot of other treatment steps the centre.For example, processing such as rate-matched, scrambling are arranged after chnnel coding; After precoding, Resource Unit RE mapping and ofdm signal generation etc. can also be arranged.

Because the up-downgoing channel between user equipment (UE) and the base station eNB is a nonsymmetric channel; Therefore, base station eNB need confirm to be used for to send to the modulation and the encoding scheme MCS of the data of user equipment (UE) based on the information of the relevant down channel of user equipment (UE) feedback.

In the downlink transfer of LTE-A, user equipment (UE) carries out to each code word to the process that reports of eNB feedback channel quality indication (CQI).User equipment (UE) estimates channel matrix according to the pilot tone that eNB sends, calculate in view of the above then precoding vector and and then obtain CQI, with to base station feedback.The base station obtains after the CQI, according to the value of feedback of UE, and other some reference factors, the data that for example need transmit, available through-put powers etc. distribute corresponding M CS, physical resource unit etc. for UE.

With reference now to Fig. 3,, it shows the schematic logical flow chart according to the method for one embodiment of the present invention.Below in conjunction with wireless communication network environments shown in Figure 1 100, the flow process among Fig. 3 is elaborated.

Base station eNB and an illustrative user device UE have been shown among Fig. 3.As shown in the figure, in step S301, base station eNB is sent reference signal RS to user equipment (UE)." pilot tone " signal that reference signal RS just often says is to offer receiving terminal by transmitting terminal to be used for channel estimating, synchronously or a kind of known signal of channel detection.

Then, in step 302, user equipment (UE) can carry out channel estimating from the reference signal that base station eNB receives according to it, thereby generates channel quality indicator (CQI).Particularly, how carrying out channel estimating is very mature technique of this area, can consult " Digital Communication " that John G.Proakis is shown, repeats no more here.

In one embodiment, CQI can indicate Unified coding speed and each layer modulation scheme separately of all layers that code word is mapped to.Hereinafter will be described modulation scheme and this unified code rate how UE calculated/confirmed each layer in detail.

In step S303, user equipment (UE) sends to eNB with the CQI that generates, and uses when selecting suitable MCS for the code word that will send to UE for eNB.

In step S304, eNB receives the CQI from UE.Then in step S305; ENB is at least partly based on this CQI; For the code word that will be transferred to UE is selected MCS; Wherein on all layers that this code word is shone upon, can use identical code rate, and on each layer, can use modulation scheme separately according to channel instruction, these modulation schemes can be identical or different.

After having confirmed MCS, eNB can encode to code word and modulates according to determined MCS, after suitably handling, sends to UE.

In step S306, UE receives the data from eNB.Then, in step S307, UE carries out the demodulation sign indicating number to the data that receive.Because code word can different still code rates be identical in the modulation scheme of each layer, therefore, UE carries out demodulation to each layer respectively to code word; To all layers, the code word unification after the demodulation is decoded.

Although the whole flow process of top reference method is described execution mode of the present invention, it will be appreciated by those skilled in the art that execution mode of the present invention can comprise more or less step.

Hereinafter will be described the Unified coding speed how user equipment (UE) calculated/confirmed the modulation scheme of each layer that code word is shone upon and be used for all layers in detail.At first provide as giving a definition.

K: Resource Unit number;

L: the number of plies that code word is shone upon;

F (x, y): when code rate be x, when code length is y, the ratio of the bit error rate of information bit and the bit error rate of coded-bit.

The variable that defines during below for every layer of code word CW of hypothesis:

r _l: the code rate of l layer;

m _l: the modulation bit number of l layer for example, is 2 bits for QPSK, is 4 bits for 16QAM, is 6 bits for 64QAM, or the like;

B _l: the information bit of the code word on the l layer, wherein B _l=Km _lR _l

The information errored bit number of

l layer;

BER _{L_C}: the coded-bit bit error rate of l layer;

BER _l: the information bit bit error rate of l layer, wherein BER _l=f (r _l, B _l) BER _{L_C}

In embodiments of the present invention, when a code word was mapped at least one layer, it used identical code rate at all layers, and can use different modulation schemes at each layer.Therefore, for purpose of brevity, execution mode of the present invention also can be called and mix the MCS scheme.Below be variable to mixing MCS scheme of the present invention definition.

r ^h: to the code rate of all layers;

B ^h: the information bit of the code word on all layers,

BER ^H_C: the coded-bit bit error rate on all layers;

BER ^h: the information bit bit error rate on all layers, wherein BER ^h=f (r ^h, B ^h) BER ^H_C

$s_l:\frac{f(r^h,B^h)}{f(r_l,B_l)}.$

Based on above definition, in an embodiment of the invention, the modulation scheme of the compute codeword multilayer of shining upon and unified code rate as follows.

At first, each layer that user equipment (UE) shines upon to code word calculates CQI independently, or claims MCS-(r _l, m _l) (confirming MCS because CQI is mainly used in), wherein r _l, m _lBe respectively code rate and the modulation bit number that is used for the l layer.The method of calculating CQI to each layer separately is being known in the art, and such as based on singular value decomposition, repeats no more here.The ground that is without loss of generality can suppose that singular value has the index l that successively decreases.

Then, be that the distribution of l layer counted m corresponding to the modulation bit that is calculated _lModulation scheme.

At last, to all layers that code word is shone upon, the highest code rate of selecting to satisfy following formula 1 is as unified code rate r ^h:

$r^h\·\underset{l=1}{\overset{L}{\mathrm{\Σ}}}\frac{s_l}{r_l}\≤1$ (formula 1)

Can calculate s according to multiple mode _lIn one embodiment, s _lCan be similar to value is:

(formula 2)

Top r ^hAnd s _lThe value derivation following.

Suppose to adopt every layer of MCS, as known in those skilled in the art, MCS selects corresponding to certain specific block error rate BLER point, and this can be described as:

${\mathrm{BLER}}_l=1-\underset{k=1}{\overset{B_l}{\mathrm{\Π}}}(1-{\mathrm{BER}}_l),$ Wherein, ${\mathrm{BER}}_l=\frac{n_{\mathrm{Err}}^l}{K\·m_l\·r_l}$ (formula 3)

Might as well suppose that all layers that a code word is shone upon have identical BLER, thereby can have:

${(1-{\mathrm{BER}}_l)}^{B_l}={(1-{\mathrm{BER}}_k)}^{B_k}$ (formula 4)

When the mixing MCS that utilizes according to embodiment of the present invention, variable BER _lAnd Km _lCan remain unchanged.Therefore, can obtain:

${\mathrm{BER}}^h=\frac{\underset{l=1}{\overset{L}{\mathrm{\Σ}}}{n}_{\mathrm{Err}}^l}{K\·r^h\·\underset{l=1}{\overset{L}{\mathrm{\Σ}}}{m}_l}=\frac{K\·r^h\·f(r^h,B^h)\·\underset{l=1}{\overset{L}{\mathrm{\Σ}}}{m}_l\·{\mathrm{BER}}_{l\_C}}{K\·r^h\·\underset{l=1}{\overset{L}{\mathrm{\Σ}}}{m}_l}=\frac{\underset{l=1}{\overset{L}{\mathrm{\Σ}}}(s_l\·m_l\·{\mathrm{BER}}_l)}{\underset{l=1}{\overset{L}{\mathrm{\Σ}}}{m}_l}$ (formula 5)

In formula 3 substitution formula 5, can obtain:

${\mathrm{BLER}}^h=1-{(1-{\mathrm{BER}}^h)}^{B_h}=1-{(1-\frac{\underset{l=1}{\overset{L}{\mathrm{\Σ}}}(s_l\·m_l\·(1-{(1-\mathrm{BLER})}^{\frac{1}{B_l}}))}{\underset{l=1}{\overset{L}{\mathrm{\Σ}}}{m}_l})}^{B_h}$

$\≈\frac{B_h\·\underset{l=1}{\overset{L}{\mathrm{\Σ}}}(s_l\·m_l\·(1-{(1-\mathrm{BLER})}^{\frac{1}{B_l}}))}{\underset{l=1}{\overset{L}{\mathrm{\Σ}}}{m}_l}\≈\frac{\mathrm{BLER}\·\underset{l=1}{\overset{L}{\mathrm{\Σ}}}K\·m_l\·r^h\underset{l=1}{\overset{L}{\mathrm{\Σ}}}\frac{s_l\·m_l}{K\·m_l\·r_l}}{\underset{l=1}{\overset{L}{\mathrm{\Σ}}}{m}_l}$ (formula 6)

$\≈\mathrm{BLER}\·r^h\·\underset{l=1}{\overset{L}{\mathrm{\Σ}}}\frac{s_l}{r_l}$

In the approximate calculation of formula 6, adopted the mathematical operation such as Taylor series expansion.

Note, in fact, Be BLER ^hThe upper limit, when all layers have identical BER ^hThe time, can reach this upper limit.

Therefore,, can obtain following constraints, i.e. the formula 1 that provides of front in order to keep target BLER:

$r^h\·\underset{l=1}{\overset{L}{\mathrm{\Σ}}}\frac{s_l}{r_l}\≤1$

s _lDepend on code rate r _l, r ^hAnd weaving length B ^h

According to some lists of references; The document R1-071967 of 3GPP TSG-RAN1 " DL E-UTRA Performance Checkpoint " for example, Alcatel-Lucent and Hamid R.Sadjadpour, " Interleaver Design for Turbo Codes "; IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS; Vol.19, No.5, May calendar year 2001; Can obtain the rough result to the 0.1BLER working point: code rate rising one-level causes BER to increase 100 times; Weaving length reduces half the, causes BER to increase 10 times.

Therefore, can come approximate calculation s through following straightforward procedure _l

It will be understood by those skilled in the art that and to take other modes to calculate s _lFor example, obtain s through emulation _lApproximate value.

In one embodiment, for example can be directed against the unified code rate r of all layers that code word is shone upon through the highest code rate conduct that following logic is selected to satisfy formula 1 ^h

If r ^TempIn the scope of the code rate of the modulation of all distribution

r ^h＝r ^temp

else

1 grade of invalid modulation rollback upgrades corresponding r _l, m _l

Go?to?Start；

end

End

End?start

In the above-mentioned logic, r _HighestBe under situation about not changing to the modulation of all layers distribution, the highest code rate that system supported.In real system, it can be made as r ₁

Note a kind of special circumstances of the mixing MCS that MCS of each code word is an embodiment of the present invention.

User equipment (UE) calculates after the CQI, and it is reported eNB, uses when confirming MCS for code word for eNB.In the LTE/LTE-A system, in up signaling, there are ACK/NACK, pre-coding matrix indication (PMI) and CQI (indication MCS) feedback to each code word.For the mixing MCS scheme of embodiment of the present invention, owing to only changed the modulation system of each layer that code word is shone upon, therefore, the PMI of the ACK/NACK feedback still situation with a code word of tradition is identical.When according to mixing MCS scheme of the present invention,, several solutions can be arranged for the CQI feedback.

In one embodiment, for every layer of code word a CQI is provided all (MCS) feedback also promptly.This mode can provide feedback accurately, but its cost is higher signaling consumption.

In another embodiment, all layers for a code word only feed back a CQI/MCS.For example, can only feed back the highest singular value.ENB waits other information to calculate the MCS of other layers based on the channel condition information (CSI) that this feedback, utilization obtain.Though this mode can be practiced thrift up signaling consumption, it can not accurately feed back CQI.

In another execution mode, design a kind of new CQI/MCS, it comprises modulation of each layer of code word and unified code rate.For example, its form can for:

Can find out that from above-mentioned form CQI can be relevant with the number of plies.This mode can be fed back CQI exactly, can practice thrift up signaling consumption again.

Fig. 4 shows the exemplary block diagram according to the device of the base station eNB side of an embodiment of the invention.

As shown in Figure 4, device 400 can comprise receiving system 401, choice device 402 and dispensing device 403.

Receiving system 401 receives the CQI feedback from UE.In one embodiment, this CQI feedback comprises modulation scheme of each layer that shines upon with code word and the relevant information of code rate of all layers.

Then, choice device 402 part at least feeds back based on this CQI, for the code word that will be transferred to UE is selected MCS.Can know from the feedback of CQI, on all layers that this code word is shone upon, can use identical code rate, and on each layer, can use identical or different modulation scheme according to channel quality.

After having confirmed MCS, eNB can encode to code word and modulates (not shown) according to determined MCS, after suitably handling, sends to UE through dispensing device 403.

Fig. 5 shows the exemplary block diagram according to the user terminal UE side of one embodiment of the present invention.

As shown in Figure 5, device 500 can comprise receiving system 501, CQI generating apparatus device 502, dispensing device 503, demodulating equipment 504 and decoding device 505.

Receiving system 501 can receive various signals from base station eNB, such as reference signal RS, data flow or code word CW and other signalings.When receiving RS, it is delivered to CQI generating apparatus 502.

Then, CQI generating apparatus 502 can carry out channel estimating according to the reference signal RS that receives, thereby generates channel quality indicator (CQI).

In one embodiment, CQI can indicate Unified coding speed and each layer modulation scheme separately of all layers that code word is mapped to.

In one embodiment, the configuration of CQI generating apparatus is used for: each layer that shines upon to code word calculates the modulation scheme of being distributed independently; To all layers that code word is shone upon, select to satisfy the code rate r of the highest code rate of following formula as all layers ^h:

$r^h\·\underset{l=1}{\overset{L}{\mathrm{\Σ}}}\frac{s_l}{r_l}\≤1,$

Wherein

r ^hBe code rate to all layers, B ^hIt is the information bit of the code word on all layers; r _lBe the code rate of l layer when hypothesis adopts every layer of code word scheme, B _lIt is the information bit of the code word on the l layer when hypothesis adopts every layer of code word scheme; Function f (x, y) expression when code rate be x, when code length is y, the ratio of the bit error rate of information bit and the bit error rate of coded-bit; L is the number of plies that code word is shone upon, l=1 ..., L.

In one embodiment, calculate s by following formula _l:

Then, CQI generating apparatus 502 offers dispensing device 503 with the CQI that is generated, to send to eNB.

When receiving system 501 received the data from eNB, these data were sent to demodulating equipment 504 after suitably handling.Because code word can different still code rates be identical in the modulation scheme of each layer, therefore, UE carries out demodulation to each layer respectively to code word; To all layers, the code word unification after the demodulation is decoded.For example, demodulating equipment 504 can comprise a plurality of demodulators, carries out demodulation respectively with the code word to each layer.Though in demodulating equipment 504, only show two demodulators among Fig. 5, it will be understood by those skilled in the art that the demodulator that other numbers can also be arranged, it is relevant with the number of plies that code word is shone upon.

After the demodulation, data are sent to decoding device 505 to decode.

Only the purpose of property has provided Fig. 4 and Fig. 5 presented for purpose of illustration.It will be understood by those skilled in the art that in device 400 and 500 and can also comprise miscellaneous part.For example, can also comprise such as code device, modulating device, precoder etc. in the device 400.Given device can realize that also other are functional.For example, the dispensing device among Fig. 4 403 can send pilot tone etc. to UE.

Need to prove that also execution mode of the present invention can be realized with software, firmware, hardware or their combination.Hardware components can utilize special logic to realize; Software section can be stored in the memory, and by suitable instruction execution system, for example microprocessor or special designs hardware are carried out.

Should be noted that for the present invention is more readily understood top description has been omitted to be known for a person skilled in the art and possibly to be essential some ins and outs more specifically for realization of the present invention.

The purpose that specification of the present invention is provided is in order to explain and to describe, rather than is used for exhaustive or the present invention is restricted to disclosed form.As far as those of ordinary skill in the art, many modifications and changes all are conspicuous.

Therefore; Selecting and describing execution mode is in order to explain principle of the present invention and practical application thereof better; And those of ordinary skills are understood, under the prerequisite that does not break away from essence of the present invention, all modifications all falls within the protection scope of the present invention that is limited claim with change.

Claims (14)

1. communication means comprises:

The indication of receive channel quality; And

At least part is based on said channel quality indication; For code word is selected modulation and encoding scheme; One of them code word is mapped at least one layer; Said code word still can be used identical or different modulation scheme according to channel quality at each layer in the identical code rate of all layers use of being shone upon.

2. method according to claim 1, wherein said channel quality indication comprises and modulation scheme of said each layer and the relevant information of code rate of said all layers.

3. communication means comprises:

For each code word generates the channel quality indication when selecting modulation and encoding scheme, to use; One of them code word is mapped at least one layer; Said code word still can be used identical or different modulation scheme according to channel quality at each layer in the identical code rate of all layers use of being shone upon; And

Send said channel quality indication.

4. method according to claim 3, wherein said channel quality indication comprises and modulation scheme of said each layer and the relevant information of code rate of said all layers.

5. method according to claim 3 further comprises:

Receive said code word;

To each layer, code word is carried out demodulation respectively; And

To all layers, the code word unification after the demodulation is decoded.

6. method according to claim 3 wherein generates the channel quality indication and comprises:

Calculate the modulation scheme of being distributed independently to said each layer;

To all layers, select to satisfy the code rate r of the highest code rate of following formula as all layers ^h:

$r^h\·\underset{l=1}{\overset{L}{\mathrm{\Σ}}}\frac{s_l}{r_l}\≤1,$

Wherein

r ^hBe code rate to all layers, B ^hIt is the information bit of the code word on all layers; r _lBe the code rate of l layer when hypothesis adopts every layer of code word scheme, B _lIt is the information bit of the code word on the l layer when hypothesis adopts every layer of code word scheme; Function f (x, y) expression when code rate be x, when code length is y, the ratio of the bit error rate of information bit and the bit error rate of coded-bit; L is the number of plies that code word is shone upon, l=1 ..., L.

7. method according to claim 6 wherein, is calculated s by following formula _l:

M wherein _lIt is the modulation bit number of l layer.

8. communicator comprises:

Receiving system is used for the indication of receive channel quality; And

Choice device; Be used at least partly based on said channel quality indication; For code word is selected modulation and encoding scheme; One of them code word is mapped at least one layer, and said code word still can be used identical or different modulation scheme according to channel quality at each layer in the identical code rate of all layers use of being shone upon.

9. based on the described device of claim 8, wherein said channel quality indication comprises and modulation scheme of said each layer and the relevant information of code rate of said all layers.

10. communicator comprises:

Channel quality indication generating apparatus; Be used to each code word and generate the channel quality indication when selecting modulation and encoding scheme, to use; One of them code word is mapped at least one layer; Said code word still can be used identical or different modulation scheme according to channel quality at each layer in the identical code rate of all layers use of being shone upon; And

Dispensing device is used to send said channel quality indication.

11. based on the described device of claim 10, wherein said channel quality indication comprises and modulation scheme of said each layer and the relevant information of code rate of said all layers.

12. device according to claim 10 further comprises:

Receiving system is used to receive said code word;

Demodulating equipment is used for to each layer code word being carried out demodulation respectively; And

Decoding device is used for to all layers the code word unification after the demodulation being decoded.

13. device according to claim 9, wherein said channel quality indication generating apparatus further configuration is used for:

Calculate the modulation scheme of being distributed independently to said each layer;

To all layers, select to satisfy the code rate r of the highest code rate of following formula as all layers ^h:

$r^h\·\underset{l=1}{\overset{L}{\mathrm{\Σ}}}\frac{s_l}{r_l}\≤1,$

Wherein

r ^hBe code rate to all layers, B ^hIt is the information bit of the code word on all layers; r _lBe the code rate of l layer when hypothesis adopts every layer of code word scheme, B _lIt is the information bit of the code word on the l layer when hypothesis adopts every layer of code word scheme; Function f (x, y) expression when code rate be x, when code length is y, the ratio of the bit error rate of information bit and the bit error rate of coded-bit; L is the number of plies that code word is shone upon, l=1 ..., L.

14. device according to claim 13 wherein, calculates s by following formula _l:

M wherein _lIt is the modulation bit number of l layer.

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