CN110445594B - Data transmission auxiliary non-orthogonal pilot frequency design method - Google Patents

Data transmission auxiliary non-orthogonal pilot frequency design method Download PDF

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CN110445594B
CN110445594B CN201910674732.1A CN201910674732A CN110445594B CN 110445594 B CN110445594 B CN 110445594B CN 201910674732 A CN201910674732 A CN 201910674732A CN 110445594 B CN110445594 B CN 110445594B
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CN110445594A (en
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李祥明
蒋露
叶能
潘建雄
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Beijing Institute of Technology BIT
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/0001—Systems modifying transmission characteristics according to link quality, e.g. power backoff
    • H04L1/0033—Systems modifying transmission characteristics according to link quality, e.g. power backoff arrangements specific to the transmitter
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/0001—Systems modifying transmission characteristics according to link quality, e.g. power backoff
    • H04L1/0036—Systems modifying transmission characteristics according to link quality, e.g. power backoff arrangements specific to the receiver
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L25/00—Baseband systems
    • H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
    • H04L25/0202—Channel estimation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00—Arrangements affording multiple use of the transmission path
    • H04L5/003—Arrangements for allocating sub-channels of the transmission path
    • H04L5/0048—Allocation of pilot signals, i.e. of signals known to the receiver

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Abstract

The invention relates to a data transmission auxiliary non-orthogonal pilot frequency design method, belonging to the technical field of demodulation reference signal design and channel estimation. Reducing the candidate space of the estimated channel parameters from the whole complex domain to a set with a limited size, and selecting the most appropriate channel from the candidate space according to the amplitude of a historical channel or a demodulation LLR (log likelihood ratio) or a decoding check result; in the most suitable channel, a non-orthogonal data transmission mode is designed based on a factor graph, a non-orthogonal DMRS transmission mode and a transmission symbol are constructed, then signal estimation is carried out by using the non-orthogonal pilot frequency and data in a combined mode, and finally data recovery is carried out according to the signal estimation. The non-orthogonal pilot frequency design method can reduce the requirement on pilot frequency resources, and a large number of DMRS ports are provided under the conditions of not improving complexity and limited resources; the performance of channel estimation is improved compared to existing schemes, and data recovery performance is good.

Description

Data transmission auxiliary non-orthogonal pilot frequency design method
Technical Field
The invention relates to a data transmission auxiliary non-orthogonal pilot frequency design method, belonging to the technical field of demodulation reference signal design and channel estimation.
Background
With the development of communication technology in China, the application of three 5G scenes (eMBB, URLLC and mMTC) is gradually improved, the number of users is gradually increased, the application of NOMA (Non-orthogonal Multiple Access) is increasingly wide, pilot frequency is one of factors influencing the performance of NOMA, and large-scale superposition transmission based on NOMA needs more DMRS ports to realize channel estimation. However, the existing techniques may bring larger time delay and higher computational complexity, so that researches on DMRS (Demodulation Reference Signal) patterns and CE (Channel Estimation) methods that satisfy multiple ports, low time delay and high accuracy at the same time are needed. DMRS is used in LTE for coherent demodulation of PUSCH and PUCCH channels. The existing research direction mainly comprises the following aspects: 1) sequence design of orthogonal DMRS, including Goldsequence-based QPSK, DFT-S-OFDM, and Zadoff-Ch sequences. 2) Adding extra DMRS to improve weak users in NOMAAnd (4) detection accuracy. And dividing the DMRS into three types, namely orthogonal DMRS, quasi-orthogonal DMRS and non-DMRS according to research content. Orthogonal DMRSs are studied by Fujitsu (sparse pattern), LG (SIC-based CE), Intel (OCC). The adoption of orthogonal DMRS can ensure the accuracy, but reduce the resource utilization rate and is limited by the number of DMRS ports. The research on quasi-orthogonal DMRS is from companies such as samsung, while the research on ZTE is about the Data-Only transmission mode, which can realize joint estimation of Data and channels, but results in great search complexity. Because blind channel estimation requires searching for and selecting from all possible channel states based on data; assuming that N users are superposed on 1 RE, where the constellation size of each user is M, there may be M on the RENEach constellation point corresponding to a size of MNThis results in a more complex search.
Therefore, the research on the DMRS pattern which simultaneously satisfies multiple ports, has low time delay and high accuracy, and is assisted by data transmission is a problem addressed by the present patent.
Disclosure of Invention
Aiming at the condition of the rapid increase of the number of users and considering that the pilot frequency has great influence on the performance of NOMA, the invention provides a non-orthogonal pilot frequency design method for assisting data transmission.
The core idea of the data transmission auxiliary non-orthogonal pilot frequency design method is as follows:
the method comprises the following steps of performing channel estimation by using the combination of non-orthogonal pilot frequency and data, and performing data recovery according to a channel estimation result, specifically: reducing the candidate space of the estimated channel parameters from the whole complex domain to a set with a limited size, and selecting the most appropriate channel from the candidate space according to the amplitude of a historical channel or a demodulation LLR (log likelihood ratio) or a decoding check result; designing a non-orthogonal data transmission mode based on a factor graph in the most suitable channel, constructing a non-orthogonal DMRS transmission mode and a transmission symbol, further performing signal estimation by using non-orthogonal pilot frequency and data combination, and finally performing data recovery according to the non-orthogonal data transmission mode and the transmission symbol, namely reducing the size of a channel parameter candidate set to M at a receiving end through the combination processing and interference deletion of the non-orthogonal data and the non-orthogonal DMRS;
wherein the transmission symbols include regular pilot symbols and differential pilot symbols.
The data transmission system on which the data transmission auxiliary non-orthogonal pilot frequency design method depends comprises a DMRS transmitting end and a DMRS receiving end;
the DMRS transmitting terminal adopts parallel SIC of a plurality of initial users, transmits orthogonal DMRS for users with weak power or after the SIC is sequenced, and transmits one of the orthogonal DMRS for users with the lowest historical BER;
the DMRS receiving end adopts one of SIC receiving and iterative receiving based on a DataGraph factor graph and a DmrsGraph factor graph;
a data transmission auxiliary non-orthogonal pilot frequency design method is defined based on the following:
definition 1: a non-orthogonal data transmission factor graph DataGraph ═ B, S, E };
wherein B ═ BiI ═ 1 … } represents a user node;
S＝{Sjj 1 … represents the time-frequency resource grid node used by data transmission;
wherein, the time frequency Resource lattice is Resource Element, which is called RE for short; the time-frequency resource grid nodes are also called RE nodes;
Eijrepresents BiAt SjAn edge on which data is transmitted;
e represents a set of edges;
Xijis shown at EijTransmitted complex data symbols;
definition 2: non-orthogonal DMRS transmission factor graph DmrsGraph ═ { B, Sdmrs，Eo，Ediff}；
Wherein B is as defined for B in DataGraph in definition 1;
SdmrsRE nodes used for representing DMRS transmissions; eoRepresenting the edge on which the regular pilot symbols are transmitted, EdiffRepresenting the edges on which the differential pilot symbols are transmitted;
definition 3: user BiAt SjThe side information when transmitting the conventional DMRS is EoIj, the symbol transmitted at this time is denoted as P, the symbol P is at the DMRS transmitting end andDMRS receivers are all known;
definition 4: user BiAt SjThe edge of the upper transmission differential DMRS symbol is marked as Ediff_ij；
Definition 5: eo_rec,EdiffThe rec respectively represents a non-orthogonal DMRS transmission sequence and a position;
definition 6: specifying the set of adjacent user node edges of Sj as N ^ B _ SjE', definition with BiThe set of adjacent RE node edges is N ^ S _ BiE'; wherein E' may be EoOr Ediff；
The data transmission auxiliary non-orthogonal pilot frequency design method comprises the steps of designing Dmrsgrap at a DMRS transmitting end and designing Dmrsgraph at a DMRS receiving end;
the DmrsGrap design of the DMRS transmitting end comprises the following steps:
step 1: RE node S determining DMRS transmission usagedmrsInitializing the DataGraph as { B, S, E } according to the non-orthogonal data transmission mapping relation;
wherein B, S in DataGraph and E in DataGraph are defined as 1;
step 2: initializing DmrsGraph ═ B, Sdmrs,Eo,Ediff}；
Wherein DmrsGraph is defined in definition 2; RE node S for DMRS transmissiondmrsDetermined by step 1, E0And EdiffAre all initialized to an empty set; b in DataGraph has the same meaning as B in DmrsGraph;
and step 3: initialization Eo_rec,EdiffRec is an empty set;
and 4, step 4: judging whether the B is empty or not, and ending the method or jumping to the step 5 according to the judgment result whether the B is empty or not, wherein the method specifically comprises the following steps:
4.1 if B is empty, i.e. all transmission tasks are finished, output EoRec and EdiffRec, and according to EoRec and EdiffTransmitting DMRS and data by using the receiver, and ending the method;
wherein the output EoRec and EdiffRec denotes a non-orthogonal DMRS transmission sequence andlocation, i.e., dmrspatattern;
after sending data, the corresponding receiving end receives the data as Ydata(ii) a After the DMRS is transmitted, the corresponding receiving end receives data as Ydmrs；
4.2 if B is not empty, jumping to step 5;
and 5: will be reacted with SjThe number of adjacent user node edges is according to | N ^ B _ SjE is arranged from small to large as J ═ J1，j2，j3…]；
Wherein, | N ^ B _ SjE represents the node S with REjThe number of all adjacent user node edges;
the number of elements for initializing the cycle count value, setting the Boolean value of the working mode and setting the maximum value of the cycle count to be J is recorded as JmaxInitializing a loop count value idx to 1;
wherein S isjRepresents the j-th RE node used by data transmission;
N^B_Sje represents and SjA set of adjacent user node edges;
step 6: judging the current J according to the elements in the J generated in the step 5*N ^ B _ S in the case of j (idx)j *_EoAnd N ^ B _ Sj *_EdiffIf N ^ B _ Sj *_EoAnd N ^ B _ Sj *_EdiffJumping to step 7 if all are empty sets; otherwise, making idx equal to idx +1, and jumping to 6. A;
wherein j is*From j1Start, in turn j2，j3，…j*The subscript of (a) is idx;
wherein j is*Reference numeral representing the current cycle, J (idx) represents the idx-th element in sequence J generated in step 5; sj *Represents the j (th)*A RE node; n ^ B _ Sj *_EoRepresenting the sum of S when the normal pilot is transmittedj *A set of adjacent user node edges; n ^ B _ Sj *_EdiffRepresenting the sum of S when transmitting the differential pilotj *Set of adjacent user node edgesCombining;
6, A: judging whether the loop count value idx has reached the maximum loop count value JmaxAnd determining how to perform the method, specifically:
if the maximum cycle count value J has been reachedmaxThen expand SdmrsAnd jumping to the step 1; if not, jumping to the step 7;
wherein S is expandeddmrsRefers to increasing the number of REs;
and 7: determining | N ^ B _ SjIf _ E | is equal to 1, then step 7.a is performed, otherwise step 7.B is performed, specifically:
7, A: if so | N ^ B _ SjE | ═ 1, representing N ^ B _ S at this timej *Only one element in _E, i.e. with Sj *The number of adjacent users is only 1, and is marked as Bk(ii) a Jumping to step 8;
7, B: if so | N ^ B _ SjIf E is not equal to 1, then find N ^ B _ Sj *The user with the maximum power and/or the lowest code rate and/or the strongest protection degree in E is marked as BkA 1 is mixing Eo_kj*Addition to EoAnd EoIn rec; for all N ^ B _ Sj *In E, BW(w ≠ k), will
Figure BDA0002142895130000041
Addition to EdiffAnd EdiffJumping to step 8 in rec;
wherein E iso_kj*Indicates that user k is at jth*Transmitting side information of the conventional pilot frequency on the RE; eoAnd EoRec is defined in definitions 2 and 5; b isW(w ≠ k) represents other user nodes of non-user k;
and 8: for N ^ S _ BkAll RE nodes S in _ EmA 1 is mixing EkmDeleting from E; for N ^ Sdmrs_Bk_EoAll of S in (1)dmrsN, will EoKln from EoDeleting; for all N ^ Sdmrs_Bk_EdiffS in (1)dmrsN, will EdiffKln from EdiffDeleting; most preferablyThen B is mixedkDeleting the data from the set B, and then turning to the step 4;
wherein, N ^ Sdmrs_Bk_EoTo a user node BkA set of adjacent transmitting conventional pilot RE node edges; sdmrsN represents the nth node used for DMRS transmission; eoKln represents that user k sends side information of the conventional pilot frequency on the nth RE node; n ^ Sdmrs_Bk_EdiffRepresenting and user node BkA set of adjacent transmitting differential pilot RE node edges; ediffKln represents the side information of the differential pilot frequency sent by the user k on the nth RE node;
the DmrsGrap design of the DMRS receiving end comprises the following steps:
step I: judging whether the set B of the user nodes is empty or not, and determining whether to finish the receiving method, specifically comprising the following steps:
i.1, if yes, completing the method;
if not, jumping to the step II;
step II: find all RE nodes Sj1…Sjk…SjKWherein each SjkCan ensure that both condition 1) and condition 2) are satisfied, or only condition 3) is satisfied, record user BikWhere i is a counting variable starting from 1:
1)N^B_Sjk_Ediffcontained in N ^ B _ Sjk_E；
2) From the set N ^ B _ SjkDeleting NbS in _Ejk_EdiffAfter all the elements in (1), only one element,
notation Bik；
3)|N^B_SjkE | ═ 1 or | N ^ B _ Sjk_Ediff|+|N^B_Sjk_Eo|＝1；
Wherein S isjKA j-th RE node used for transmission on behalf of user k; n ^ B _ Sjk_EdiffRepresenting the sum of S when transmitting the differential pilotjKA set of adjacent user node edges; n ^ B _ SjkE represents the time when data is transmitted and SjKA set of adjacent user node edges; n ^ B _ Sjk_EoRepresenting the sum of S when the normal pilot is transmittedjKA set of adjacent user node edges;
step III: according to all B found in step IIikFor each BikAdding the data and the dmrs to estimate possible channel parameters, and obtaining a channel parameter candidate set with the size of M; adopting the M channel parameters to carry out data recovery, and selecting the most appropriate channel parameter;
wherein "most suitable" is defined as one of maximizing the sum of absolute values of the demodulated LLRs, or making the CRC check correct, or minimizing the absolute difference of the channel parameter from the previous time instant;
step IV: complete all BikAfter the data recovery of (3), the transmitted signal and the transmitted DMRS are reconstructed from the "checked data", and then the two are respectively transmitted from YdataAnd YdmrsAnd deleting the above B from Bik(ii) a From N ^ B _ SjkE and N ^ B _ Sjk_EdiffMiddle deletion and BikThe relevant edges are finally returned to the step I;
if no checking link exists, the 'data passing the checking' is corrected into 'all data';
wherein, YdataAnd YdmrsAnd (4) representing the received data corresponding to the non-orthogonal DMRS transmitting sequence, which is shown in the step 4 of DmrsGraph design at the DMRS transmitting end.
Advantageous effects
Compared with the prior pilot frequency design, the non-orthogonal pilot frequency design method assisted by data transmission has the following beneficial effects:
1. compared with the existing orthogonal DMRS technology, the non-orthogonal pilot frequency design method assisted by data transmission can reduce the requirement on pilot frequency resources, namely, more DMRS ports are supported under the condition that the resource consumption is not increased, namely, more user numbers are supported, because the method is the non-orthogonal DMRS;
2. in the case of increasing the number of users, the complexity remains substantially unchanged;
3. the performance of channel estimation is improved compared to existing schemes, and data recovery performance is good.
Drawings
Fig. 1 is a diagram of non-orthogonal data transmission factors proposed in definitions 1-5 in the data transmission aided non-orthogonal pilot design method proposed in the present invention;
fig. 2 is a diagram of non-orthogonal DMRS transmission factors defined in the method for designing non-orthogonal pilots for assisting data transmission according to the present invention;
fig. 3 illustrates a transmission manner of data transmission resources and DMRS transmission resources in the data transmission aided non-orthogonal pilot design method proposed in the present invention;
fig. 4 shows an embodiment 1 of a data transmission aided non-orthogonal pilot design method according to the present invention: PDMA8UE4 RE.
Detailed Description
The following describes a method for designing non-orthogonal pilots for data transmission assistance according to the present invention in detail with reference to the accompanying drawings and specific embodiments.
Example 1
This embodiment describes that the data transmission-aided non-orthogonal pilot design method according to the present invention is based on a non-orthogonal data transmission mode and a factor graph representation method, designs a non-orthogonal mapping manner of DMRS and transmission symbols of DMRS (including a conventional pilot symbol E)oAnd a differential pilot symbol Ediff)；
And the receiving end constructs orthogonal RE by linear calculation and interference deletion by utilizing the linearity between the received data and the received DMRS, and then completes channel estimation and data recovery according to a smaller channel parameter search space.
FIG. 1 is a schematic diagram of an implementation of a non-orthogonal data transmission factor graph, definition 1, with components B, S and E of DataGraph labeled; wherein B ═ BiI-1 … represents a user node, S-SjJ 1 … represents that data transmission uses time-frequency resource grid (RE) nodes, and E represents a set of edges; when B is presentiAt SjWhen data is transmitted, EijBelongs to a set E, 8 user nodes and 4RE nodes exist in the graph;
fig. 2 is an implementation schematic diagram of a DMRS transmission factor graph, i.e., definition 2; it is composed ofIn EoRepresenting the edge on which the regular pilot symbols are transmitted, EdiffRepresenting the edges on which the differential pilot symbols are transmitted;
when the user BiAt SjOn transmitting a conventional DMRS, then EoIn which the element E is containedoIj, the symbol transmitted at this time is denoted as P, which is known at both the transmitting and receiving ends;
when the user BiAt SjWhen transmitting differential DMRS, then EdiffIn which the element E is containeddiff_ij。
Fig. 3 shows how data transmission resources and DMRS transmission resources need to adopt adjacent transmission; the solid line box in the figure is the data transmission resource, and the spot box is the DMRS transmission resource; due to the variability of the channel, the adjacent transmission of the data transmission resource and the DMRS transmission resource is more beneficial to the performance improvement;
fig. 4 is an example of a 7-user, 4RE factor graph used in the implementation of the data transmission aided non-orthogonal pilot design method of the present invention; according to the design method, only 3 REs are needed for DMRS transmission, 4/7 resources are saved, and therefore the port number is increased.
The joint design of the DataGraph and the DmrsGraph mainly aims to ensure that users with the degree of 1 can appear in each iteration during the joint iteration (ensure that BP reception can continue).
Considering the case of 6 users and 4 REs specifically, pattern for representing data and DMRS by a matrix is shown as follows, where rows of the matrix represent REs and columns of the matrix represent users, and the total power for transmitting pilots by the users is P.
Figure BDA0002142895130000081
Wherein the second row of DMRS may also transmit pilots to enhance the estimation of the channel, but not in this example;
the DMRS pattern is designed by the following process:
step A: determining physical resources of DMRS, in this example 4RE resources, and initializing DataGraph { (B, S, E) } and DmrssGraph ═{B,Sdmrs,Eo,Edifd}; initialization EoRec and EdiffRec is an empty set;
and B: in data, the number of users per RE node is checked, in this case 3 users per RE node, i.e. | N ^ B _ SjkE | are equal, so the cycle is performed directly in the order of the indices of RE, i.e., J ═ 1,2,3,4]；
And C: for j*1 or Sj *＝S1Easy to know N ^ B _ Sj *_E0And N ^ B _ Sj *_EdiffAll are empty sets; if j*If the DMRS patterns on 4 REs are designed to be 5, the algorithm is ended, and E is outputoRec and EdiffRec, the final dmrsp pattern.
Step D: for j*＝1，|N^B_SjkE | ═ 3, find the user with the greatest power in RE1 as UE 1; the remaining users are user 3 and user 5;
step E: recording the side information of the regular pilot frequency sent by the user 1 in EoAnd EoIn rec, the side information of the differential pilots transmitted by the remaining users 3 and 5 is recorded in EdiffAnd EdiffIn rec;
step F: deleting all data side information and DMRS side information related to the user 1, and continuously designing the pattern of the DMRS on the next RE; j is a function of*＝j*+1, go back to step C;
the following example is an example of receiver-side algorithm design:
after the transmitting end transmits the designed DMRS, the following steps are carried out:
step a: the 1 st user on the 1 st RE meets the condition a) and the condition b in the DmrsGrap design step II of the DMRS receiving end);
step b: adding the data and the dmrs, and recovering the data according to the channel parameters to recover the user signal, as follows:
Figure BDA0002142895130000091
wherein, the dotted line part is the signal mainly used for estimating the channel, and the solid line part is the data and dmrs related to this step;
step c: the 6 th user on the 2 nd RE meets the condition a) and the condition b in the DmrsGrap design step II of the DMRS receiving end);
step d: based on the signal recovered in step b, the signal of user 1 is deleted, and the data is added to dmrs to recover the signal of user 6, as follows:
Figure BDA0002142895130000092
step e: the 4 th user on the 3 rd RE meets the condition c in the DmrsGrap design step II of the DMRS receiving end);
step f: based on the signal recovered in step d, the signal of user 6 is deleted, and data is added to dmrs, so that the signal of user 4 can be recovered according to the channel parameters, as follows:
Figure BDA0002142895130000093
step g: the 2 nd user on the 4 th RE meets the condition a) and the condition b in the DmrsGrap design step II of the DMRS receiving end);
step h: based on the signal recovered in step f, the signal of user 4 is deleted, and data is added to dmrs, so that the signal of user 2 can be recovered according to the channel parameters, as follows:
Figure BDA0002142895130000101
step i: similarly, based on the signals of the user 1, the user 2, the user 4, and the user 6 deleted in the above steps, the signals of the user 3 and the user 5 can be restored, as follows:
Figure BDA0002142895130000102
the above example uses 3 REs to transmit DMRSs of 6 users, saving resources. The core idea of DMRS pattern design is to ensure that an RE with a degree of 1 can be obtained after each channel estimation and deletion, and a DMRS pattern can be obtained by giving a pattern for data transmission.
The above detailed description is intended to illustrate the objects, aspects and advantages of the present invention, and it should be understood that the above detailed description is only exemplary of the present invention and is not intended to limit the scope of the present invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims (4)

1. A method for designing a non-orthogonal pilot for data transmission assistance, comprising: the supported data transmission system comprises a DMRS transmitting terminal and a DMRS receiving terminal;
the DMRS transmitting terminal adopts parallel SIC of a plurality of initial users, transmits orthogonal DMRS for users with weak power or users with the sequence of SIC and transmits one of the orthogonal DMRS to the user with the lowest historical BER;
the DMRS receiving end adopts one of SIC receiving and iterative receiving based on a DataGraph factor graph and a DmrsGraph factor graph;
the data transmission auxiliary non-orthogonal pilot frequency design method is defined based on the following steps:
definition 1: a non-orthogonal data transmission factor graph DataGraph ═ B, S, E };
wherein B ═ BiI ═ 1 … } represents a user node;
S＝{Sjj 1 … represents the time-frequency resource grid node used by data transmission;
wherein, the time frequency Resource lattice is Resource Element, which is called RE for short; the time-frequency resource grid nodes are also called RE nodes;
Eijrepresents BiAt SjAn edge on which data is transmitted;
e represents a set of edges;
Xijis shown at EijPlural number of transmissionsA data symbol;
definition 2: non-orthogonal DMRS transmission factor graph DmrsGraph ═ { B, Sdmrs，Eo，Ediff}；
Wherein B is as defined for B in DataGraph in definition 1;
SdmrsRE nodes used for representing DMRS transmissions; eoRepresenting the edge on which the regular pilot symbols are transmitted, EdiffRepresenting the edges on which the differential pilot symbols are transmitted;
definition 3: user BiAt SjThe side information when transmitting the conventional DMRS is EoIj, the symbol transmitted at this time is denoted as P, and the symbol P is known at both the DMRS transmitting end and the DMRS receiving end;
definition 4: user BiAt SjThe edge of the upper transmission differential DMRS symbol is marked as Ediff_ij；
Definition 5: eo_rec，EdiffThe rec respectively represents a non-orthogonal DMRS transmission sequence and a position;
definition 6: provision of SjThe set of adjacent user node edges is N ^ B _ SjE', definition with BiThe set of adjacent RE node edges is N ^ S _ BiE'; wherein E' may be EoOr Ediff；
The data transmission auxiliary non-orthogonal pilot frequency design method comprises the steps of designing Dmrsgrap at a DMRS transmitting end and designing Dmrsgraph at a DMRS receiving end;
the DmrsGrap design of the DMRS transmitting end comprises the following steps:
step 1: RE node S determining DMRS transmission usagedmrsInitializing the DataGraph as { B, S, E } according to the non-orthogonal data transmission mapping relation;
wherein B, S in DataGraph and E in DataGraph are defined as 1;
step 2: initializing DmrsGraph ═ B, Sdmrs，Eo，Ediff}；
Wherein DmrsGraph is defined in definition 2; RE node S for DMRS transmissiondmrsDetermined by step 1, E0And EdiffAre all initialized to an empty set; in DataGraphB is the same as B in DmrsGraph;
and step 3: initialization Eo_rec，EdiffRec is an empty set;
and 4, step 4: judging whether the B is empty or not, and ending the method or jumping to the step 5 according to the judgment result whether the B is empty or not, wherein the method specifically comprises the following steps:
4.1 if B is empty, i.e. all transmission tasks are finished, output EoRec and EdiffRec, and according to EoRec and EdiffTransmitting DMRS and data by using the receiver, and ending the method;
wherein the output EoRec and EdiffThe rec respectively represents a non-orthogonal DMRS sending sequence and a position, namely DMRS pattern;
after sending data, the corresponding receiving end receives the data as Ydata(ii) a After the DMRS is transmitted, the corresponding receiving end receives data as Ydmrs；
4.2 if B is not empty, jumping to step 5;
and 5: will be reacted with SjThe number of adjacent user node edges is according to | N ^ B _ SjE is arranged from small to large as J ═ J1，j2，j3...]；
Wherein, | N ^ B _ SjE represents the node S with REjThe number of all adjacent user node edges;
the number of elements for initializing the cycle count value, setting the Boolean value of the working mode and setting the maximum value of the cycle count to be J is recorded as JmaxInitializing a loop count value idx to 1;
wherein S isjRepresents the j-th RE node used by data transmission;
N^B_Sje represents and SjA set of adjacent user node edges;
step 6: judging the current J according to the elements in the J generated in the step 5*N ^ B _ S in the case of j (idx)j *_EoAnd N ^ B _ Sj *_EdiffIf N ^ B _ Sj *_EoAnd N ^ B _ Sj *_EdiffJumping to step 7 if all are empty sets; otherwise, making idx equal to idx +1, and jumping to 6. A;
wherein j is*From j1Start, in turn j2，j3，...j*The subscript of (a) is idx;
wherein j is*Reference numeral representing the current cycle, J (idx) represents the idx-th element in sequence J generated in step 5; sj *Represents the j (th)*A RE node; n ^ B _ Sj *_EoRepresenting the sum of S when the normal pilot is transmittedj *A set of adjacent user node edges; n ^ B _ Sj *_EdiffRepresenting the sum of S when transmitting the differential pilotj *A set of adjacent user node edges;
6, A: judging whether the loop count value idx has reached the maximum loop count value JmaxAnd determining how to perform the method, specifically:
if the maximum cycle count value J has been reachedmaxThen expand SdmrsAnd jumping to the step 1; if not, jumping to the step 7;
and 7: determining | N ^ B _ SjIf _ E | is equal to 1, then step 7.a is performed, otherwise step 7.B is performed, specifically:
7, A: if so | N ^ B _ SjE | ═ 1, representing N ^ B _ S at this timej *Only one element in _E, i.e. with Sj *The number of adjacent users is only 1, and is marked as Bk(ii) a Jumping to step 8;
7, B: if so | N ^ B _ SjIf E is not equal to 1, then find N ^ B _ Sj *The user with the maximum power and/or the lowest code rate and/or the strongest protection degree in E is marked as BkA 1 is mixing Eo_kj*Addition to EoAnd EoIn rec; for all N ^ B _ Sj *In E, BW(w ≠ k), will
Figure FDA0002542480590000031
Addition to EdiffAnd EdiffJumping to step 8 in rec;
wherein E iso_kj*Indicates that user k is at jth*Transmitting regular pilots on one RESide information; eoAnd EoRec is defined in definitions 2 and 5; b isW(w ≠ k) represents other user nodes of non-user k;
and 8: for N ^ S _ BkAll RE nodes S in _ EmA 1 is mixing EkmDeleting from E; for N ^ Sdmrs_Bk_EoAll of S in (1)dmrsN, will EoKln from EoDeleting; for all N ^ Sdmrs_Bk_EdiffS in (1)dmrsN, will EdiffKln from EdiffDeleting; finally B iskDeleting the data from the set B, and then turning to the step 4;
wherein, N ^ Sdmrs_Bk_EoTo a user node BkA set of adjacent transmitting conventional pilot RE node edges; sdmrsN represents the nth node used for DMRS transmission; eoKln represents that user k sends side information of the conventional pilot frequency on the nth RE node; n ^ Sdmrs_Bk_EdiffRepresenting and user node BkA set of adjacent transmitting differential pilot RE node edges; ediffKln represents the side information of the differential pilot frequency sent by the user k on the nth RE node;
the DmrsGrap design of the DMRS receiving end comprises the following steps:
step I: judging whether the set B of the user nodes is empty or not, and determining whether to finish the receiving method, specifically comprising the following steps:
i.1, if yes, completing the method;
if not, jumping to the step II;
step II: find all RE nodes Sj1…Sjk…SjKWherein each SjkCan ensure that both condition 1) and condition 2) are satisfied, or only condition 3) is satisfied, record user BikWhere i is a counting variable starting from 1:
1)N^B_Sjk_Ediffcontained in N ^ B _ Sjk_E；
2) From the set N ^ B _ SjkDeleting NbS in _Ejk_EdiffAfter all elements in (A), only one element remains, denoted as Bik；
3)|N^B_SjkE | ═ 1 or | N ^ B _ Sjk_Ediff|+|N^B_Sjk_Eo|＝1；
Wherein S isjKA j-th RE node used for transmission on behalf of user k; n ^ B _ Sjk_EdiffRepresenting the sum of S when transmitting the differential pilotjKA set of adjacent user node edges; n ^ B _ SjkE represents the time when data is transmitted and SjKA set of adjacent user node edges; n ^ B _ Sjk_EoRepresenting the sum of S when the normal pilot is transmittedjKA set of adjacent user node edges;
step III: according to all B found in step IIikFor each BikAdding the data and the dmrs to estimate possible channel parameters, and obtaining a channel parameter candidate set with the size of M; adopting the M channel parameters to carry out data recovery, and selecting the most appropriate channel parameter;
step IV: complete all BikIf there is a check link after the data recovery, the recovered data is checked, the transmitted signal and the transmitted DMRS are reconstructed according to the data passing the check, and then the signal and the DMRS are respectively reconstructed from YdataAnd YdmrsAnd deleting the above B from Bik(ii) a From N ^ B _ SjkE and N ^ B _ Sjk_EdiffMiddle deletion and BikAnd (4) the relevant edges finally return to the step I.
2. The method of claim 1, wherein the method further comprises: the "most suitable" in step III is defined as one of maximizing the sum of absolute values of the demodulated LLRs, or making the CRC check correct, or minimizing the absolute difference of the channel parameter from the previous time instant.
3. The method of claim 1, wherein the method further comprises: in A, expand SdmrsRefers to increasing the number of REs.
4. The method of claim 1, wherein the method further comprises: in step IV, if there is no verification link, the "data passing verification" is modified to "all data".
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