CN102474335B - Method and apparatus for data relay and data decoding - Google Patents

Abstract

The invention provides a method and an apparatus for forwarding multiple packets from multiple user terminals in a relay station, and a method and an apparatus for decoding the multiple packets in a base station. The relay station performs joint modulation-based network coding processing or analog network coding processing for the multiple packets from the multiple user terminals, and forwards a joint modulation-based network coding packet or an analog network coding packet to the base station. The base station receives the multiple packets from the respective multiple user terminals and the joint modulation-based network coding packet or the analog network coding packet from the relay station, and performs joint soft combining and decoding to them. The invention can effectively save the uplink frequency spectrum resources of the link section between the relay station to the base station, reduce power consumption in the relay station, and can improve the forwarding efficiency of the relay station and ensure reception quality.

Description

For method and the device of data relay and data decode

Technical field

The present invention relates to wireless communication system, relate more specifically to a kind of method and corresponding equipment thereof that utilizes relaying to carry out transfer of data in wireless communication system, can effectively save the radio spectrum resources of up link, reduce the power consumption of relay station, can also improve relay station forward efficiency and keep good receptivity simultaneously.

Background technology

In LTE-A cordless communication network, relaying is back-up system dilatation and the important technical of expanding the coverage area.In the up link of LTE-A cordless communication network, generally need the information of relaying from multiple user terminal UE.Traditional trunking scheme is the information that forwards one by one multiple user terminals.

For example, as shown in Figure 1, grouping P1 and the P2 from user terminal 11 and 12 respectively relayed to respectively eNodeB31 by relay station 21.For P1 and these two groupings of P2, relay station 21 still needs to use the resource suitable with these two block lengths to carry them.In TDM system, in the time that served UE number increases, the pass-through mode one by one shown in Fig. 1 will bring compared with long delay.In FDM system, the pass-through mode one by one shown in Fig. 1 needs a large amount of frequency spectrum resources.Due in cordless communication network, the Radio Resource of communication link is very limited, therefore, is necessary to take the scheme of some saving Radio Resources to carry out relaying.

In the PCT international application of submitting on April 27th, 2009, propose a kind of about the XOR network code scheme of multi-user's relaying and about the soft combining scheme of eNB the applicant.As shown in Figure 2, by XOR network code mode, with 1 XOR bit represent 2 bits from 2 UE, can save like this 50% forwarding resource, but receptivity is not fine.Therefore, need to take into account the more effective pass-through mode of receptivity.

Summary of the invention

The present invention is on the basis of background technology, proposed a kind of in relay station to the technical scheme forwarding from multiple groupings of multiple user terminals, and these multiple groupings from user terminal are combined the technical scheme of soft merging decoding in base station.

According to an aspect of the present invention, proposed a kind of in the relay station of cordless communication network for to the method forwarding from the grouping of user terminal, comprise the following steps: receive the multiple groupings from multiple user terminals respectively; Described multiple groupings are carried out to the network code processing based on combined modulation, to obtain a grouping of the network code based on combined modulation; And the described grouping of the network code based on combined modulation is sent to base station.

According to a further aspect in the invention, proposed a kind of in the relay station of cordless communication network for to the method forwarding from the grouping of user terminal, comprise the following steps: receive the multiple groupings from multiple user terminals respectively; Described multiple groupings are carried out to analog network coding processing, to obtain an analog network coding grouping; And described analog network coding grouping is sent to base station.

According to another aspect of the invention, proposed a kind of in the base station of cordless communication network for to the method for decoding from the grouping of user terminal, comprise the following steps: receiving respectively and divide into groups from multiple groupings of multiple user terminals and from the network code based on combined modulation of relay station, should the network code grouping based on combined modulation be wherein that described multiple groupings that described relay station is received are respectively carried out obtaining after the network code processing based on combined modulation; And described multiple groupings and the grouping of the described network code based on combined modulation are combined to soft merging decoding.

In accordance with a further aspect of the present invention, proposed a kind of in the base station of cordless communication network for to the method for decoding from the grouping of user terminal, comprise the following steps: receive respectively and divide into groups from multiple groupings of multiple user terminals and from the analog network coding of relay station, wherein this analog network coding grouping is that described multiple groupings that described relay station is received are respectively carried out based on obtaining after analog network coding processing; And to described multiple groupings and describedly combine soft merging decoding based on analog network coding grouping.

The present invention can save the uplink spectrum resource of relay station to base station link section effectively, reduces the power consumption in relay station, can also improve relay station forward efficiency and keep good receptivity simultaneously.

Accompanying drawing explanation

By reference to below in conjunction with accompanying drawing to adopted detailed description of preferred embodiment, above-mentioned purpose of the present invention, advantage and feature will become apparent, wherein:

Fig. 1 is the network topology structure schematic diagram of traditional multiple user uplink relaying;

Fig. 2 is the network topology structure schematic diagram of the multiple user uplink relaying of existing employing XOR network code;

Fig. 3 is the schematic diagram that forwards grouping according to the relay station of the cordless communication network of the embodiment of the present invention;

Fig. 4 show according in the relay station of first embodiment of the invention for the flow chart to the method forwarding from the grouping of multiple user terminals;

Fig. 5 shows the flow chart of the sub-steps the example 1 in the situation that according to the step S403 of first embodiment of the invention;

Fig. 6 shows the 16QAM planisphere in current non-patent literature 36.211;

Fig. 7 shows the planisphere for 16QAM customization according to first embodiment of the invention;

Fig. 8 show according to the example 1 of first embodiment of the invention in eNB for the flow chart to the method for decoding from the grouping of user terminal;

Fig. 9 shows the sub-steps flow chart according to the step S803 in the example 1 of first embodiment of the invention;

Figure 10 shows according to the decoding schematic block diagram in eNB in the example 1 of first embodiment of the invention;

Figure 11 shows the flow chart of the sub-steps the example 2 in the situation that according to the step S403 of first embodiment of the invention;

Figure 12 show according to first embodiment of the invention in the relay station of cordless communication network for the structured flowchart of the retransmission unit 1200 to forwarding from the grouping of multiple users;

Figure 13 show according to first embodiment of the invention in the eNB of cordless communication network for the structural representation of the decoding device 1300 to decoding from the grouping of user terminal;

Figure 14 show according in the relay station of second embodiment of the invention for the flow chart to the method forwarding from the grouping of multiple user terminals;

Figure 15 shows the flow chart of the sub-steps the example 3 in the situation that according to the step S1403 of second embodiment of the invention;

Figure 16 shows the planisphere corresponding with the mapping table shown in table 2;

Figure 17 shows the flow chart of the sub-steps the example 4 in the situation that according to the step S1403 of second embodiment of the invention;

Figure 18 show according to second embodiment of the invention in the relay station of cordless communication network for the structured flowchart of the retransmission unit 1800 to forwarding from the grouping of multiple users;

Figure 19 show according to second embodiment of the invention in the eNB of cordless communication network for the structural representation of the decoding device 1900 to decoding from the grouping of user terminal; And

Figure 20 shows the simulation curve figure according to 4 kinds of each self-corresponding packet error rates of trunking plan of the present invention.

Embodiment

Describe the preferred embodiments of the present invention in detail below in conjunction with accompanying drawing.

Fig. 3 is the forwarding scheme schematic diagram of relay station 300 of the present invention.It should be noted that, only show two user terminals 301 and 302 in Fig. 3, those of ordinary skill in the art will be understood that technical scheme of the present invention is not limited to two user terminals, but is applicable to the situation of multiple user terminals.As can be seen from Figure 3, the difference of the trunking plan of mentioning in forwarding scheme of the present invention and background parts is, the present invention adopts combined modulation network code (JM NC) scheme and analog network coding (ANC) scheme that are different from XOR network code.

Illustrate combined modulation network code scheme of the present invention and analog network coding scheme by enumerating respectively the first embodiment and the second embodiment below.

[the first embodiment]

Fig. 4 show according in the relay station of first embodiment of the invention for the flow chart to the method forwarding from the grouping of multiple user terminals.

As shown in Figure 4, in step 401, relay station receives the multiple groupings from multiple user terminals respectively.In step 403, relay station carries out the network code processing based on combined modulation to described multiple groupings, to obtain a grouping of the network code based on combined modulation.In step 405, the described grouping of the network code based on combined modulation is sent to eNB by relay station.

In wireless communication field, existing relaying is all that single bag forwards, and is divided into amplification forwarding (AF) trunking scheme and decodes forwarding (DF) trunking scheme.Below, will be respectively take AF relaying and DF relay scene as example, the network code processing based on combined modulation in the step S403 in Fig. 4 is specifically described.

Example 1: multiple user uplink combined modulation (MUJM) DF relaying

Fig. 5 shows the flow chart of the sub-steps the example 1 in the situation that according to the step S403 of first embodiment of the invention.

As shown in Figure 5, in step S501, relay station carries out demodulation code to described multiple groupings.In step S503, relay station judges whether described multiple grouping is all correctly decoded.In the present embodiment, relay station carries out above-mentioned judgement by CRC check.In the situation that described multiple groupings are all correctly decoded, relay station carries out chnnel coding (step S505) to described multiple groupings, and then carries out combined modulation (step S507).If exist at least one grouping not to be correctly decoded, carry out so combined modulation also nonsensical, in this case, relay station is switched to the pattern of traditional AF relaying.That is to say, relay station still amplifies one by one the grouping receiving and forwards operation.

Carry out the concrete mapping mode of the combined modulation in description of step S507 below in conjunction with Fig. 6 and Fig. 7.

For with LTE-A system compatible, need to consider the modulation type of LTE-A data channel, i.e. QPSK, 16QAM and 64QAM.Two QPSK symbols can combined modulation be a 16QAM symbol.A QPSK symbol and a 16QAM symbol can combined modulation be a 64QAM symbol.

Next, describe as a 16QAM symbol as example take two QPSK symbol combined modulations.

Fig. 6 shows the 16QAM planisphere in current non-patent literature 3GPP TS36.211, as seen from the figure, and wherein the first two table of bits aspect limit, the particular location in latter two table of bits aspect limit.For example, under the application scenarios shown in Fig. 3, as the bit from 2 UE is connected, and be the first two bit by the bit modulation from UE1.From Fig. 6, can find out clearly, UE1 will have the better performance than UE2, and the performance gap between UE1 and UE2 is great disparity too.

Therefore, combined modulation should adopt more suitable mapping mode.In order to make to there is suitable performance from the bit of two UE, should rearrange planisphere.As shown in Figure 7, make to distribute along x axle from the bit of UE1, and distribute along y axle from the bit of UE2.In this case, UE1 and UE2 have identical performance.

Table 1 shows the combined modulation mapping table corresponding with planisphere in Fig. 7.In order to be customization planisphere as shown in Figure 7 by the bit combined modulation from 2 UE in meeting LTE planisphere, first needing the bit mapping from 2 UE is the corresponding bit on the planisphere in table 1 the 5th row, then modulates according to LTE planisphere.Concrete mapping relations are as shown in table 1.

Table 1: combined modulation mapping table

In fact, constellation mapping pattern is not limited to this.In other cases, design map principle in a similar manner.

Fig. 8 show according to the example 1 of first embodiment of the invention in eNB for the flow chart to the method for decoding from the grouping of user terminal.

Below in conjunction with Fig. 3 and Fig. 8, the eNB31 that is arranged in Fig. 3 is elaborated to the process of decoding from the grouping of user terminal 11 or 12.

First, in step S801, eNB31 receives the network code based on the combined modulation grouping from relay station 21, and respectively from grouping P1 and the P2 of user terminal 11 and 12.Wherein, from the network code based on the combined modulation grouping of relay station 21 be received respectively by relay station 21 respectively from two grouping P1 of user terminal 11 and 12 and P2 carry out the network code based on combined modulation as shown in Figure 4 process after gained.

Conventionally,, due to the processing delay in relay station 21, eNB31 first receives grouping P1 and the P2 from user terminal 11 and 12 respectively.It should be noted that, different due to the wireless communication link of user terminal 11 or 12 to relay station 21 and user terminal 11 or 12 to eNB31, same grouping P1 or P2 that relay station 21 is received from eNB31 may be different.For example, due to relay station 21 from user terminal 11 or 12 close to, grouping P1 or P2 that it receives may receive entirely true; And due to eNB31 from user terminal 11 or 12 away from, may reception can there is mistake in the grouping P1 that it receives or P2.After the single grouping that receives direct link, eNB carries out demodulation, channel-decoding to single grouping, if correct channel-decoding does not need to carry out soft combination with network code grouping.

It should be noted that, those of ordinary skill in the art will be understood that particularly, and the send mode of grouping P1 and P2 can be time-division, code point, frequency division, empty grading mode, due to grouping send mode and the present invention without direct relation, the present invention does not repeat them here.

Then,, in step S803, the grouping P1 from user terminal and P2 and the grouping of the described network code based on combined modulation are combined to soft merging decoding.

Fig. 9 shows the sub-steps flow chart according to the step S803 in the example 1 of first embodiment of the invention.

First,, in step S901, eNB31 carries out soft merging to the soft information of soft information separately of described multiple groupings and the grouping of the described network code based on combined modulation.

First, eNB31 obtains the soft information of soft information separately of described multiple grouping and the grouping of described analog network coding, the sequence of the log-likelihood ratio (LLR) that what the soft information here referred to is exactly in each grouping each coded-bit is corresponding.

Below the computational process of the log-likelihood ratio to a coded-bit is elaborated.

Suppose that a symbol in grouping P1 that user terminal 11 sends is s ₁, that eNB31 receives is y ₁:

y ₁＝h ₁·s ₁+n ₁ (1)

Wherein, h ₁for the transmission coefficient of user terminal 11 to eNB31, n ₁for variance is σ ²the noise of normal distribution, then symbol s ₁likelihood ratio be:

$\mathrm{LLR}\left(s_1\right)=\log P\left({\mathrm{<figure-callout\; id="1"\; label="y"\; filenames="HPA0000133524660000321.png"\; state="\{\{state\}\}">y</figure-callout>}}_1\right|s_{1i})=-\frac{{(y_1-h_1{s}_{1i})}^2}{2{\mathrm{\&sigma;}}^2}---\left(2\right)$

Wherein, s _1ifor symbol s ₁all possible value.For example,, for QPSK symbol, i=1～4.

Then, carry out compute sign s by expression formula (3) ₁in the bit likelihood ratio of bit j:

$\mathrm{LLR}\left(b_j\right)=\log \frac{P\left({\mathrm{<figure-callout\; id="1"\; label="y"\; filenames="HPA0000133524660000321.png"\; state="\{\{state\}\}">y</figure-callout>}}_1\right|b_j=1)}{P\left({\mathrm{<figure-callout\; id="1"\; label="y"\; filenames="HPA0000133524660000321.png"\; state="\{\{state\}\}">y</figure-callout>}}_1\right|b_j=0)}=\log \frac{\underset{s_i;b_j=1}{\mathrm{\&Sigma;}}P\left({\mathrm{<figure-callout\; id="1"\; label="y"\; filenames="HPA0000133524660000321.png"\; state="\{\{state\}\}">y</figure-callout>}}_1\right|s_i)}{\underset{s_k;b_j=0}{\mathrm{\&Sigma;}}P\left({\mathrm{<figure-callout\; id="1"\; label="y"\; filenames="HPA0000133524660000321.png"\; state="\{\{state\}\}">y</figure-callout>}}_1\right|s_k)}=\log \frac{\underset{s_i;b_j=1}{\mathrm{\&Sigma;}}\exp \left(\mathrm{LLR}\left(s_i\right)\right)}{\underset{s_k;b_j=0}{\mathrm{\&Sigma;}}\exp \left(\mathrm{LLR}\left(s_k\right)\right)}---\left(3\right)$

Wherein, the bit that i and k comprise for each symbol.For example, for QPSK symbol, i and k=1～2.

Then, bit LLR sequence is inputed to channel decoder.If the channel-decoding of two groupings is correct, for example CRC check result is correct, and the sequence of data bits of the decoded P1 of memory channel and P2, without carrying out further soft merging processing.For example, if having the channel-decoding of any one grouping (P1 divides into groups) incorrect, need this grouping P1 to carry out soft merging processing.

In the second time slot, eNB carries out identical processing to P2.In the 3rd time slot, the combined modulation symbol s in the grouping of the network code based on the combined modulation PNC that eNB receives _nCas shown in expression formula (4)

y _NC＝h _R，B·s _NC+n _R，B· (4)

For the information to about P1 is carried out soft combination, with first b in P1 ₁for example, according to LLR in MAP (Maximum a Posterior, maximum a posteriori probability) criterion _bdefinition $\widetilde{\mathrm{LLR}}\left(b_1\right)=\log \frac{P[{\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="HPA0000133524660000321.png"\; state="\{\{state\}\}">b</figure-callout>}}_1=1|y_{\mathrm{NC}}]}{P[{\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="HPA0000133524660000321.png"\; state="\{\{state\}\}">b</figure-callout>}}_1=0|y_{\mathrm{NC}}]}=\log \frac{P[{\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="HPA0000133524660000321.png"\; state="\{\{state\}\}">b</figure-callout>}}_1=1,y_{\mathrm{NC}}]}{P[{\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="HPA0000133524660000321.png"\; state="\{\{state\}\}">b</figure-callout>}}_1=0,y_{\mathrm{NC}}]}$ Carry out soft combination.

After receiving single grouping and the grouping of the network code based on combined modulation, can calculate as follows LLR _bsequence

$\widetilde{\mathrm{LLR}}\left(b_k\right)=\log \frac{\underset{s_{\mathrm{JM}}}{\mathrm{\&Sigma;}}P\left[y_{\mathrm{NC}}\right|s_{\mathrm{NC}}:b_k=1\left]P\right[{\mathrm{<figure-callout\; id="1"\; label="y"\; filenames="HPA0000133524660000321.png"\; state="\{\{state\}\}">y</figure-callout>}}_1|s_1:b_k=1]P[{y_2|s}_2:b_k=1]}{\underset{s_{\mathrm{JM}}}{\mathrm{\&Sigma;}}P\left[y_{\mathrm{NC}}\right|s_{\mathrm{NC}}:b_k=0\left]P\right[{\mathrm{<figure-callout\; id="1"\; label="y"\; filenames="HPA0000133524660000321.png"\; state="\{\{state\}\}">y</figure-callout>}}_1|s_1:b_k=0]P\left[y_2\right|s_2:b_k=0]}=\log \frac{\underset{s_{\mathrm{NC}},{\mathrm{<figure-callout\; id="1"\; label="s"\; filenames="HPA0000133524660000321.png"\; state="\{\{state\}\}">s</figure-callout>}}_1\&CenterDot;s_2:b_k=1}{\mathrm{\&Sigma;}}{e}^{{\mathrm{LLR}}_{s_{\mathrm{NC}}}+{\mathrm{LLR}}_{s_1}+{\mathrm{LLR}}_{s_2}}}{\underset{s_{\mathrm{NC}},{\mathrm{<figure-callout\; id="1"\; label="s"\; filenames="HPA0000133524660000321.png"\; state="\{\{state\}\}">s</figure-callout>}}_1\&CenterDot;s_2:b_k=0}{\mathrm{\&Sigma;}}{e}^{{\mathrm{LLR}}_{s_{\mathrm{NC}}}+{\mathrm{LLR}}_{s_1}+{\mathrm{LLR}}_{s_2}}}$

(5)

Wherein, k=1,2,3,4.K=1, the LLR of the 2nd, P1, and k=3, the LLR of the 4th, P2.For example, first b ₁, take the joint probability sum in last 8 row in table 1 as molecule, take the joint probability sum in 8 row as denominator.According to the LLR of formula (5) and table 1 derivation P1 _bsequence.

In step 903, by derived LLR _bsequence inputs to Turbo decoder, so that P1 is carried out to channel-decoding.Can utilize similar mode, the information of P2 and the single grouping and the combined modulation that receive are combined.This soft combining scheme as shown in figure 10.

As can be seen from Figure 10, in order to combine with combined modulation information, only need an extra preliminary treatment, i.e. soft combination block shown in the dash area of Figure 10.In the time adopting max-log-MAP algorithm (approximate data), this pretreated complexity is very low.

Example 2: multiple user uplink combined modulation (MUJM) AF relaying

Figure 11 shows the flow chart of the sub-steps the example 2 in the situation that according to the step S403 of first embodiment of the invention.

As shown in figure 11, compared with example 1, relay station in example 2, after the grouping receiving from user terminal, is not decoded to the symbol receiving, but is calculated the symbol LLR (step S1101) of each grouping in described multiple grouping.Then, at step S1103, relay station estimates by ML (maximum likelihood) principle the symbol receiving, and this can calculate by above-mentioned expression formula (2).Finally, relay station to estimated go out receiving symbol carry out combined modulation, to obtain combined modulation grouping (step S1105).

For example, the mapping relations shown in relay station reference table 1 are carried out combined modulation, will be specifically a 16QAM symbol from two QPSK sign map of 2 UE.

Due to this example repeating to eNB be also the network code grouping based on combined modulation, thereby in this example, eNB adopts with example 1 similar soft combining scheme (as shown in figure 10) and decodes, and just repeats no more here.

Figure 12 show according to first embodiment of the invention in the relay station of cordless communication network for the structured flowchart of the retransmission unit 1200 to forwarding from the grouping of multiple users.In Figure 12, retransmission unit 1200 comprises first receiving device 1202, for receiving the multiple groupings from multiple user terminals respectively; Network encoding apparatus 1204, for described multiple groupings are carried out to the network code processing based on combined modulation, to obtain a grouping of the network code based on combined modulation; And first dispensing device 1206, for the described grouping of the network code based on combined modulation is sent to eNB.

Preferably, network encoding apparatus 1204 comprises: the first demodulation code device, for described multiple groupings are carried out to demodulation code; The first channel coding device, in the situation that described multiple groupings are all correctly decoded, carries out chnnel coding to described multiple groupings; And the first combined modulation device, for described multiple groupings are carried out to combined modulation.

Preferably, network encoding apparatus 1204 comprises: LLR calculation element, for calculating the symbol LLR of each grouping of described multiple groupings; Estimation unit, for estimating receiving symbol according to maximum-likelihood criterion; And the second combined modulation device, carry out combined modulation for the receiving symbol to estimated.

Figure 13 show according to first embodiment of the invention in the eNB of cordless communication network for the structural representation of the decoding device 1300 to decoding from the grouping of user terminal.In Figure 13, decoding device 1300 comprises: the 3rd receiving system 1302, dividing into groups from multiple groupings of multiple user terminals and from the network code based on combined modulation of relay station for receiving respectively, should the network code grouping based on combined modulation be wherein that described multiple groupings that described relay station is received are respectively carried out obtaining after the network code processing based on combined modulation; And the first soft merging decoding device 1304, for described multiple groupings and the grouping of the described network code based on combined modulation are combined to soft merging decoding.Wherein, this first soft merging decoding device 1304 comprises: the first soft merging device, for the soft information of soft information separately of described multiple groupings and the grouping of the described network code based on combined modulation is carried out to soft merging; And first decoding device, input to the channel decoder (not shown) of decoding for the result that soft merging is obtained.

[the second embodiment]

Figure 14 show according in the relay station of second embodiment of the invention for the flow chart to the method forwarding from the grouping of multiple user terminals.

As shown in figure 14, in step 1401, relay station receives the multiple groupings from multiple user terminals respectively.In step 1403, relay station carries out analog network coding processing to described multiple groupings, to obtain an analog network coding grouping.In step 1405, described analog network coding grouping is sent to eNB by relay station.

Below, will be respectively take AF relaying and DF relay scene as example, the analog network coding processing in the step S1403 in Figure 14 is specifically described.

Example 3: multiple user uplink analog network coding (ANC) DF relaying

Figure 15 shows the flow chart of the sub-steps the example 3 in the situation that according to the step S1403 of second embodiment of the invention.

As shown in figure 15, in step S1501, relay station carries out demodulation code to described multiple groupings.In step S1503, relay station judges whether described multiple grouping is all correctly decoded.In the present embodiment, relay station carries out above-mentioned judgement by CRC check.In the situation that described multiple groupings are all correctly decoded, relay station carries out Channel Coding and Modulation (step S1505) to described multiple groupings, then utilizes pre-determined factor to be weighted summation (step S1507).If exist at least one grouping not to be correctly decoded, relay station only plays the effect of traditional AF (amplify and forward) relaying.This means that relay station still amplifies one by one the grouping receiving and forwards operation.

Under the application scenarios shown in Fig. 3, relay station, after the grouping receiving from UE1 and UE2, carries out relaying modulation and channel-decoding to the P1 from UE1 with from the P2 of UE2.If correctly decoded, these two groupings, carry out Channel Coding and Modulation to the data bit of these two groupings, then usage factor k ₁and k ₂(being also referred to as ANC coefficient) is weighted summation to the modulation symbol of these two groupings, obtains y _nC=k ₁s ₁+ k ₂s ₂, and forward it to eNB.

If relaying keeps fixed transmission power, first tackle coefficient k ₁and k ₂be normalized.Secondly, k ₁and k ₂should there is equal mould, to keep two justices between UE.Otherwise the UE that coefficient module is larger will have good performance.These conditions can be served as definition coefficient k above ₁and k ₂factor.Here exemplarily defined,

At exemplary coefficient

basis on, provided ANC mapping table as shown in table 2.

Table 2ANC mapping table

It should be noted that table 2 is only example, ANC coefficient and mapping table are not limited to this.

Figure 16 shows the planisphere corresponding with the mapping table shown in table 2.The constellation of QPSK meets the planisphere in current non-patent literature 3GPP TS36.211.

In this example, eNB adopts with example 1 similar soft combining scheme (as shown in figure 10) and decodes.That is to say, can carry out the soft combination about ANC information by the corresponding table 2 of expression formula (5).Here just repeat no more.

Example 4: multiple user uplink analog network coding (ANC) AF relaying

Figure 17 shows the flow chart of the sub-steps the example 4 in the situation that according to the step S1403 of second embodiment of the invention.

As shown in figure 17, in step S1701, relay station does not carry out demodulation code to the symbol receiving, but directly utilize pre-determined factor to be weighted summation to receiving symbol, for example, usage factor k1 and k2 are weighted summation to symbol y1 and y2 in the grouping receiving, obtain y=k1*y1+k2*y2.

Under the application scenarios shown in Fig. 3, relay station, after the grouping receiving from UE1 and UE2, utilizes weight coefficient k ₁and k ₂(, ANC coefficient) is weighted the receiving symbol of these two groupings, obtains y _nC=k ₁y ₁+ k ₂y ₂, and forward it to eNB.

In this example, the definite and ANC mapping ruler of weight coefficient is identical with example 3, just repeats no more here.

In this example, the soft combining scheme of eNB side is identical with example 3, identical with the example 1 of aforementioned the first embodiment, also can carry out the soft combination about ANC information by the corresponding table 2 of expression formula (5).

Figure 18 show according to second embodiment of the invention in the relay station of cordless communication network for the structured flowchart of the retransmission unit 1800 to forwarding from the grouping of multiple users.In Figure 18, retransmission unit 1800 comprises: the second receiving system 1802, for receiving the multiple groupings from multiple user terminals respectively; Analog network coding device 1804, for described multiple groupings are carried out to analog network coding processing, to obtain an analog network coding grouping; And second dispensing device 1806, for described analog network coding grouping is sent to eNB.

Preferably, analog network coding device 1804 comprises: the second demodulation code device, for described multiple groupings are carried out to demodulation code; Second channel coding and modulating device, for carrying out Channel Coding and Modulation to described multiple groupings in the situation that described multiple groupings are all correctly decoded; And the first weighted sum device, for utilizing pre-determined factor to be weighted summation to described multiple groupings.

Preferably, analog network coding device 1804 comprises: the second weighted sum device, and for utilizing pre-determined factor to be weighted summation to the described multiple groupings that receive.

Figure 19 show according to second embodiment of the invention in the eNB of cordless communication network for the structural representation of the decoding device 1900 to decoding from the grouping of user terminal.As shown in figure 19, decoding device 1900 comprises: the 4th receiving system 1902, divide into groups from multiple groupings of multiple user terminals and from the analog network coding of relay station for receiving respectively, wherein this analog network coding grouping is that described multiple groupings that described relay station is received are respectively carried out based on obtaining after analog network coding processing; And the second soft merging decoding device 1904, for to described multiple groupings and described based on analog network coding grouping combine soft merging decoding.Wherein, described the second soft merging decoding device 1904 comprises: the second soft merging device, for the soft information of soft information separately of described multiple groupings and the grouping of described analog network coding is carried out to soft merging; And second decoding device, input to the channel decoder (not shown) of decoding for the result that soft merging is obtained.

Figure 20 is that explanation is according to the simulation curve figure of the performance of the soft merging of four kinds of each self-corresponding network codes of network code trunking plan of the present invention.

Here, by the emulation in Rayleigh channel, by four kinds of physical-layer network coding schemes of the present invention and traditional DF/AF relaying, XOR network code relaying with compare by the situation that there is no relaying.The variance of supposing Rayleigh fading is 1, and noise power is distributed as AWGN.Suppose that UE1 and UE2 have identical channel status.RS-eNB link has the channel status identical with UE-eNB link, and UE-RS link is than the good 5dB of UE-eNB link.Employing length is that the UMTS1/3Turbo code of 3456 bits carries out chnnel coding.Modulation system is QPSK.In addition,, for NC scheme is assessed, adopt each improvement in performance forwarding as yardstick.

As can be seen from Figure 20,10 ^-2pER place, for then saying in DF, tradition DF relaying can obtain by forwarding two subframes of two UE the improvement in performance of 2.7dB, be that unit forwarding receptivity is improved to 1.35dB/FW, the unit of XOR relaying forwards receptivity and is improved to 1.25dB/FW, and MUJM DF relaying/ANC DF relaying that the present invention proposes has the unit forwarding receptivity improvement of 1.9dB/FW.That is to say, MUJM DF relaying/ANC DF trunking plan proposed by the invention has higher unit and forwards receptivity improvement.Aspect AF relaying, ANC AF trunking plan proposed by the invention is being better than traditional AF trunking plan aspect unit forwarding receptivity improvement equally.The unit that has listed Figure 20 in table 3 forwards the improved simulation result of receptivity.

The unit of the different relayings of table 3. forwards receptivity and improves

As can be seen from Table 3, the scheme in last column has higher efficiency.According to this yardstick, in layer 2 (L2), should adopt MUJM/ANC DF as NC trunking plan.If less PER hydraulic performance decline is acceptable, can adopt XOR scheme to save the computation complexity on relaying.In layer 1 (L1), should adopt ANC AF as NC trunking plan.

In addition, can find out from the description of specification, utilize the network code trunking plan of all these types, all can save 50% forwarding resource.In addition, the performance of MUJM/ANC DF relaying is better than traditional AF relaying.On saved TTI, need not carry out relaying, can save thus 50% through-put power.AF NC scheme has extremely low complexity.

In sum, adopt trunking plan of the present invention and corresponding decoding scheme, can in keeping receptivity, effectively save frequency spectrum resource, and reduce the power consumption in relay processes, improve forward efficiency.

Although below show the present invention in conjunction with the preferred embodiments of the present invention, one skilled in the art will appreciate that without departing from the spirit and scope of the present invention, can carry out various modifications, replacement and change to the present invention.Therefore, the present invention should not limited by above-described embodiment, and should be limited by claims and equivalent thereof.

Claims (12)

1. In the relay station of cordless communication network for to the method forwarding from the grouping of user terminal, comprise the following steps:

   Receive the multiple groupings from multiple user terminals respectively;

   Described multiple groupings are carried out to demodulation code, and in the situation that described multiple groupings are all correctly decoded, described multiple groupings are carried out to chnnel coding and combined modulation, to obtain a grouping of the network code based on combined modulation; And

   The described grouping of the network code based on combined modulation is sent to base station.
2. In the relay station of cordless communication network for to the method forwarding from the grouping of user terminal, comprise the following steps:

   Receive the multiple groupings from multiple user terminals respectively;

   Calculate the symbol log-likelihood ratio of each grouping in described multiple grouping, estimate receiving symbol according to maximum likelihood principle, and to estimated go out receiving symbol carry out combined modulation, to obtain the grouping of network code based on combined modulation; And

   The described grouping of the network code based on combined modulation is sent to base station.
3. In the relay station of cordless communication network for to the method forwarding from the grouping of user terminal, comprise the following steps:

   Receive the multiple groupings from multiple user terminals respectively;

   Utilize pre-determined factor to be weighted summation to described multiple groupings, to obtain an analog network coding grouping;

   And described analog network coding grouping is sent to base station.
4. 4. method according to claim 3, wherein, further comprising the steps of before described multiple groupings are weighted to summation in the described pre-determined factor of utilizing:

   Described multiple groupings are carried out to demodulation code; And

   In the situation that described multiple groupings are all correctly decoded, described multiple groupings are carried out to chnnel coding and modulation.
5. In the relay station of cordless communication network for to the retransmission unit forwarding from the grouping of user terminal, comprising:

   First receiving device, for receiving the multiple groupings from multiple user terminals respectively;

   The first demodulation code device, for carrying out demodulation code to described multiple groupings;

   The first channel coding device, in the situation that described multiple groupings are all correctly decoded, carries out chnnel coding to described multiple groupings;

   The first combined modulation device, for described multiple groupings are carried out to combined modulation, to obtain a grouping of the network code based on combined modulation; And

   The first dispensing device, for sending to base station by the described grouping of the network code based on combined modulation.
6. In the relay station of cordless communication network for to the retransmission unit forwarding from the grouping of user terminal, comprising:

   First receiving device, for receiving the multiple groupings from multiple user terminals respectively;

   Log-likelihood calculations device, for calculating the symbol log-likelihood ratio of each grouping of described multiple groupings;

   Estimation unit, for estimating receiving symbol according to maximum likelihood principle;

   The second combined modulation device, for to estimated go out receiving symbol carry out combined modulation, to obtain the grouping of network code based on combined modulation; And

   The first dispensing device, for sending to base station by the described grouping of the network code based on combined modulation.
7. In the relay station of cordless communication network for to the retransmission unit forwarding from the grouping of user terminal, comprising:

   The second receiving system, for receiving the multiple groupings from multiple user terminals respectively;

   The second weighted sum device, for utilizing pre-determined factor to be weighted summation to described multiple groupings, to obtain an analog network coding grouping; And

   The second dispensing device, for sending to base station by described analog network coding grouping.
8. 8. retransmission unit according to claim 7, also comprises:

   The second demodulation code device, for carrying out demodulation code to described multiple groupings; And

   Second channel coding and modulating device, in the situation that described multiple groupings are all correctly decoded, described multiple groupings being carried out to Channel Coding and Modulation, carry out described weighted sum for described the second weighted sum device.
9. In the base station of cordless communication network for to a method of decoding from the grouping of user terminal, comprise the following steps:

   Receiving respectively and divide into groups from multiple groupings of multiple user terminals and from the network code based on combined modulation of relay station, should the network code grouping based on combined modulation be wherein that described multiple groupings that described relay station is received are respectively carried out obtaining after the network code processing based on combined modulation;

   Soft information to soft information separately of described multiple groupings and the grouping of the described network code based on combined modulation is carried out soft merging; And

   The result that soft merging is obtained inputs to channel decoder and decodes.
10. In the base station of cordless communication network for to a method of decoding from the grouping of user terminal, comprise the following steps:

    Receive respectively and divide into groups from multiple groupings of multiple user terminals and from the analog network coding of relay station, wherein this analog network coding grouping is that described multiple groupings that described relay station is received are respectively carried out based on obtaining after analog network coding processing;

    Soft information to soft information separately of described multiple groupings and the grouping of described analog network coding is carried out soft merging; And

    The result that soft merging is obtained inputs to channel decoder and decodes.
11. 11. 1 kinds in the base station of cordless communication network for to the decoding device of decoding from the grouping of user terminal, comprising:

    The 3rd receiving system, dividing into groups from multiple groupings of multiple user terminals and from the network code based on combined modulation of relay station for receiving respectively, should the network code grouping based on combined modulation be wherein that described multiple groupings that described relay station is received are respectively carried out obtaining after the network code processing based on combined modulation;

    The first soft merging device, for carrying out soft merging to the soft information of soft information separately of described multiple groupings and the grouping of the described network code based on combined modulation; And

    The first decoding device, inputs to channel decoder for the result that soft merging is obtained and decodes.
12. 12. 1 kinds in the base station of cordless communication network for to the decoding device of decoding from the grouping of user terminal, comprising:

    The 4th receiving system, divide into groups from multiple groupings of multiple user terminals and from the analog network coding of relay station for receiving respectively, wherein this analog network coding grouping is that described multiple groupings that described relay station is received are respectively carried out based on obtaining after analog network coding processing;

    The second soft merging device, for carrying out soft merging to the soft information of soft information separately of described multiple groupings and the grouping of described analog network coding; And

    The second decoding device, inputs to channel decoder for the result that soft merging is obtained and decodes.

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