LTE定位参考信号生成程序与标准不一致？

在定位参考信号映射到资源单元中时，频域上位置与LTE协议标准中的不一样，一直找不到原因，麻烦各路大神帮帮忙！下面附录的是程序代码！主程序：%PRS定位参考信号clc;close all;clear all;%信道为20MHz系统的参数设置N_fft=2048;   % FFT点数N_used_subcarrier=1200; %可用的子载波个数fs=30.72e6;    %系统采样频率Ts=1/fs;      %系统采样间隔N_DL_RB=100;   %资源块数目（传输带宽18MHz）N_PRS_RB=100; %分配给PRS的资源块数N_RB_SC=12;   %每个资源块的子载波数% N_id_1 = 9;     %物理层小区ID组 0 <= N_ID_1<=167% N_id_2 = 1;          %物理层小区ID组中的物理层ID 0 <= N_ID_2<=2% N_cell_id = 3* N_id_1 + N_id_2;       % 物理层小区ID 0-503N_cell_id=5;subframe_index=1; %子帧号0--9PBCH_port=1; %物理广播信道天线端口数：1、2或4N_CP=1;      %常规循环前缀：1；扩展循环前缀：0switch N_CP    case 0, N_DL_symb=6;    case 1, N_DL_symb=7;    otherwise N_DL_symb=7;endSNR=25; %信噪比% 定位参考信号映射到资源单元上recv_subframe = zeros(N_DL_RB*N_RB_SC,N_DL_symb*2);recv_subframe = rs_mapping_to_subframe_PRS(recv_subframe,subframe_index,N_cell_id,PBCH_port,N_PRS_RB,N_CP,N_DL_RB); %定位参考信号 recv_subframe = rs_mapping_to_subframe(recv_subframe,subframe_index,N_cell_id,0,N_DL_RB,N_CP);    %小区参考信号% recv_subframe = rs_mapping_to_subframe(recv_subframe,subframe_index,N_cell_id,1,N_DL_RB,N_CP);    %小区参考信号% recv_subframe = rs_mapping_to_subframe(recv_subframe,subframe_index,N_cell_id,2,N_DL_RB,N_CP);    %小区参考信号% recv_subframe = rs_mapping_to_subframe(recv_subframe,subframe_index,N_cell_id,3,N_DL_RB,N_CP);    %小区参考信号%---IFFT---recv_subframe =[zeros((N_fft-N_used_subcarrier)/2,N_DL_symb*2);recv_subframe;zeros((N_fft-N_used_subcarrier)/2,N_DL_symb*2)];IFFTed=zeros(N_fft,N_DL_symb*2);for i=1:N_DL_symb*2    IFFTed(:,i)=sqrt(N_fft)*ifft(recv_subframe(:,i),N_fft);end%---加CP----WithCP_sequence=zeros(2208,N_DL_symb*2);for i=1:14    WithCP_sequence(:,i)=CP_Insert(IFFTed(:,i).',0);endsend_signal=reshape(WithCP_sequence,1,length(WithCP_sequence)*size(WithCP_sequence,2));%---信道---%---AWGN---recv_signal=awgn(send_signal,SNR);%---去CP---recv_WithCP_sequence=reshape(recv_signal,2208,N_DL_symb*2);NoCP_sequence=zeros(N_DL_symb*2,N_fft); for i=1:N_DL_symb*2   NoCP_sequence(i,=CP_Removal(recv_WithCP_sequence(:,i),0);  end NoCP_sequence=NoCP_sequence.'; %----FFT----- FFTed=zeros(N_fft,N_DL_symb*2); for i=1:N_DL_symb*2   FFTed(:,i)=1/sqrt(N_fft)*fft(NoCP_sequence(:,i),N_fft); end %---去资源映射---调用函数：function subframe = rs_mapping_to_subframe (subframe,sub_index,N_cell_id,p,N_DL_RB,N_CP);% *************************************************************************% Function Description: (v1.0---20090513 by jiangyoubang)% This function is used for the progress of mapping the reference signals% to the relevant position in the radio subframe of antana port p in 3GPP LTE.%% usage :%     subframe = rs_mapping_to_subframe (subframe,sub_index,N_cell_id,p,N_DL_RB,N_CP);% % input parameter :%      "subframe" : the data subframe that reference signal needs to add into.%      "sub_index" : the subframe index in a radio frame. range:0~9%      "N_cell_id" : Physical layer cell identity.%      "N_CP" : For normal CP,N_CP=1; for extended CP,N_CP=0;%      "p" : The antena number %      "N_DL_RB" : Downlink bandwidth configuration. it might be 6,25,50,100% %   note : %      the generalization of the reference signal sequence%       can be found in Ref.36.211.850 %**************************************************************************% parameter that can be found in Ref.36.211-850N_RB_DL_MAX = 110;v_shift = mod(N_cell_id,6);% For N_CP=1, means normal CP; For N_CP=0, means extended CP; switch N_CP    case 0, N_DL_symb = 6;    case 1, N_DL_symb = 7;    otherwise N_DL_symb = 7;end% different p means different antana port, and the mapping process is different%参考于《移动宽带技术》----扇区参考信号定义（p79）switch p    case 0, %the subframe will go to antana port 0     for ns= 2 * sub_index : 2 * sub_index + 1         kk=mod(ns,2);         l=0;%如果p=0且l=0时，v=0（参考移动宽带技术——扇区参考信号定义）         v=0;         r_l_ns = gen_rs_seq (N_cell_id,N_CP,ns,l);% generate rs sequence         for m = 0 : 2 * N_DL_RB - 1            m1 = m + N_RB_DL_MAX - N_DL_RB + 1;            k = (6 * m + mod((v + v_shift),6)) + 1;            subframe(k,l + N_DL_symb * kk + 1) = r_l_ns(m1); %mapping rs to subframe         end         l=N_DL_symb - 3;%N_DL_symb=7         v=3;         r_l_ns = gen_rs_seq (N_cell_id,N_CP,ns,l);% generate rs sequence         for m = 0 : 2 * N_DL_RB - 1            m1 = m + N_RB_DL_MAX - N_DL_RB + 1;            k = 6 * m + mod((v + v_shift),6) + 1;            subframe(k,l + N_DL_symb * kk + 1) = r_l_ns(m1);%mapping rs to subframe         end     end    case 1, %the subframe will go to antana port 1     for ns= 2 * sub_index : 2 * sub_index + 1         kk=mod(ns,2);         l=0;         v=3;         r_l_ns = gen_rs_seq (N_cell_id,N_CP,ns,l);% generate rs sequence         for m = 0 : 2 * N_DL_RB - 1            m1 = m + N_RB_DL_MAX - N_DL_RB + 1;            k = 6 * m + mod((v + v_shift),6) + 1;            subframe(k,l + N_DL_symb * kk + 1) = r_l_ns(m1);%mapping rs to subframe         end         l=N_DL_symb - 3;         v=0;         r_l_ns = gen_rs_seq (N_cell_id,N_CP,ns,l);% generate rs sequence         for m = 0 : 2 * N_DL_RB - 1            m1 = m + N_RB_DL_MAX - N_DL_RB + 1;            k = 6 * m + mod((v + v_shift),6) + 1;            subframe(k,l + N_DL_symb * kk + 1) = r_l_ns(m1);%mapping rs to subframe         end              end    case 2, %the subframe will go to antana port 2     for ns= 2 * sub_index : 2 * sub_index + 1         kk=mod(ns,2);         l=1;         v=3*mod(ns,2);         r_l_ns = gen_rs_seq (N_cell_id,N_CP,ns,l);% generate rs sequence         for m = 0 : 2 * N_DL_RB - 1            m1 = m + N_RB_DL_MAX - N_DL_RB + 1;            k = 6 * m + mod((v + v_shift),6) + 1;            subframe(k,l + N_DL_symb * kk + 1) = r_l_ns(m1);%mapping rs to subframe         end     end    case 3, %the subframe will go to antana port 3     for ns= 2 * sub_index : 2 * sub_index + 1         kk=mod(ns,2);         l=1;         v=3+3*mod(ns,2);         %mod((v + v_shift),6)         r_l_ns = gen_rs_seq (N_cell_id,N_CP,ns,l);% generate rs sequence         for m = 0 : 2 * N_DL_RB - 1            m1 = m + N_RB_DL_MAX - N_DL_RB + 1;            k = 6 * m + mod((v + v_shift),6) + 1;            subframe(k,l + N_DL_symb * kk + 1) = r_l_ns(m1);%mapping rs to subframe         end     end    otherwise disp('illagal antana port number p .');end            function subframe = rs_mapping_to_subframe_PRS (subframe,sub_index,N_cell_id,PBCH,N_PRS_RB,N_CP,N_DL_RB);% *************************************************************************% This function is used for the progress of mapping the reference signals% to the relevant position in the radio subframe of antana port p in 3GPP LTE.% % usage :%     subframe = rs_mapping_to_subframe (subframe,sub_index,N_cell_id,p,N_DL_RB,N_CP);% % input parameter :%      "subframe" : the data subframe that reference signal needs to add into.%      "sub_index" : the subframe index in a radio frame. range:0~9%      "N_cell_id" : Physical layer cell identity.%      "N_CP" : For normal CP,N_CP=1; for extended CP,N_CP=0;%      "p" : The antena number %      "N_DL_RB" : Downlink bandwidth configuration. it might be 6,25,50,100% %   note : %   the generalization of the reference signal sequence%   can be found in Ref.36.211.850 %**************************************************************************N_RB_DL_MAX = 110; v_shift = mod(N_cell_id,6);% N_CP=1, 常规循环前缀P；N_CP=0, 扩展循环前缀; switch N_CP    case 0, N_DL_symb = 6;    case 1, N_DL_symb = 7;    otherwise N_DL_symb = 7;end% 定位参考信号映射到资源单元上if N_CP==1    %常规循环前缀    for ns = 2 * sub_index : 2 * sub_index + 1     kk=mod(ns,2);     if kk==0          l=[3,5,6];      %OFDM符号的序号     elseif (kk==1)&&(PBCH==1||PBCH==2) %kk=1且（1个或2个物理广播信道天线端口）         l=[1,2,3,5,6];   %OFDM符号的序号     elseif (kk==1)&&(PBCH==4)       %kk=1且（4个物理广播信道天线端口）         l=[2,3,5,6];   %OFDM符号的序号     end         for i=1:length(l)            r_l_ns = gen_rs_seq (N_cell_id,N_CP,ns,l(i));        % 产生定位参考信号序列            for m = 0: 2 * N_PRS_RB-1             m1 = m + N_RB_DL_MAX - N_PRS_RB+1;             k=6*(m+N_DL_RB-N_PRS_RB)+mod((6-l(i)+v_shift),6)+1; %k为子载波序号              subframe(k,l(i)+N_DL_symb*kk+1) = r_l_ns(m1);     %参考信号序列映射到复值调制符号（天线端口6）            end         end    endelse %扩展循环前缀    for ns= 2 * sub_index : 2 * sub_index + 1     kk=mod(ns,2);     if kk==0 %l的取值         l=[4,5];     elseif (kk==1)&&(PBCH==1||PBCH==2)         l=[1,2,4,5];     elseif (kk==1)&&(PBCH==4)         l=[2,4,5];     end         for i=1:length(l)            r_l_ns = gen_rs_seq (N_cell_id,N_CP,ns,l(i)); % 产生定位参考信号序列            for m = 0 : 2 * N_PRS_RB - 1             m1 = m + N_RB_DL_MAX - N_PRS_RB;             k=6*(m+N_DL_RB-N_PRS_RB)+mod((5-l(i)+v_shift),6)+1;             subframe(k,l(i)+N_DL_symb*kk+1) = r_l_ns(m1); %参考信号序列映射到复值调制符号（天线端口6）            end         end    endend% % different p means different antana port, and the mapping process is different% %参考于《移动宽带技术》----扇区参考信号定义（p79）% switch p%   case 0, %the subframe will go to antana port 0%       for ns= 2 * sub_index : 2 * sub_index + 1%          kk=mod(ns,2);%          l=0;%如果p=0且l=0时，v=0（参考移动宽带技术——扇区参考信号定义）%          v=0;%          r_l_ns = gen_rs_seq (N_cell_id,N_CP,ns,l);% generate rs sequence%          for m = 0 : 2 * N_DL_RB - 1%           m1 = m + N_RB_DL_MAX - N_DL_RB + 1;%           k = (6 * m + mod((v + v_shift),6)) + 1;%           subframe(k,l + N_DL_symb * kk + 1) = r_l_ns(m1); %mapping rs to subframe%          end% %          l=N_DL_symb - 3;%N_DL_symb=7%          v=3;%          r_l_ns = gen_rs_seq (N_cell_id,N_CP,ns,l);% generate rs sequence%          for m = 0 : 2 * N_DL_RB - 1%           m1 = m + N_RB_DL_MAX - N_DL_RB + 1;%           k = 6 * m + mod((v + v_shift),6) + 1;%           subframe(k,l + N_DL_symb * kk + 1) = r_l_ns(m1);%mapping rs to subframe%          end%       end%   case 1, %the subframe will go to antana port 1%       for ns= 2 * sub_index : 2 * sub_index + 1%          kk=mod(ns,2);%          l=0;%          v=3;%          r_l_ns = gen_rs_seq (N_cell_id,N_CP,ns,l);% generate rs sequence%          for m = 0 : 2 * N_DL_RB - 1%           m1 = m + N_RB_DL_MAX - N_DL_RB + 1;%           k = 6 * m + mod((v + v_shift),6) + 1;%           subframe(k,l + N_DL_symb * kk + 1) = r_l_ns(m1);%mapping rs to subframe%          end%          %          l=N_DL_symb - 3;%          v=0;%          r_l_ns = gen_rs_seq (N_cell_id,N_CP,ns,l);% generate rs sequence%          for m = 0 : 2 * N_DL_RB - 1%           m1 = m + N_RB_DL_MAX - N_DL_RB + 1;%           k = 6 * m + mod((v + v_shift),6) + 1;%           subframe(k,l + N_DL_symb * kk + 1) = r_l_ns(m1);%mapping rs to subframe%          end         %       end%   case 2, %the subframe will go to antana port 2%       for ns= 2 * sub_index : 2 * sub_index + 1%          kk=mod(ns,2);%          l=1;%          v=3*mod(ns,2);%          r_l_ns = gen_rs_seq (N_cell_id,N_CP,ns,l);% generate rs sequence%          for m = 0 : 2 * N_DL_RB - 1%           m1 = m + N_RB_DL_MAX - N_DL_RB + 1;%           k = 6 * m + mod((v + v_shift),6) + 1;%           subframe(k,l + N_DL_symb * kk + 1) = r_l_ns(m1);%mapping rs to subframe%          end%       end%   case 3, %the subframe will go to antana port 3%       for ns= 2 * sub_index : 2 * sub_index + 1%          kk=mod(ns,2);%          l=1;%          v=3+3*mod(ns,2);%          %mod((v + v_shift),6)%          r_l_ns = gen_rs_seq (N_cell_id,N_CP,ns,l);% generate rs sequence%          for m = 0 : 2 * N_DL_RB - 1%           m1 = m + N_RB_DL_MAX - N_DL_RB + 1;%           k = 6 * m + mod((v + v_shift),6) + 1;%           subframe(k,l + N_DL_symb * kk + 1) = r_l_ns(m1);%mapping rs to subframe%          end%       end%   case 6,%the subframe will go to antana port 6%       for ns= 2 * sub_index : 2 * sub_index + 1%          kk=mod(ns,2);%       %   otherwise disp('illagal antana port number p .');% end            function rs_seq_l_ns = gen_rs_seq (N_cell_id,N_CP,ns,l);% *************************************************************************% Function Description: (v1.0---20090428 by )% This function is used for the progress of generation of the reference %      signal sequence that is needed by cell_specific reference signal%      in 3GPP LTE.%% usage :%     rs_seq_l_ns = gen_rs_seq (N_cell_id,N_CP,ns,l);% % input parameter :%      "N_cell_id" : Physical layer cell identity.%      "N_CP" : For normal CP,N_CP=1; for extended CP,N_CP=0;%      "ns" : The slot number within a radio frame%      "l" : The OFDM symbol number within the slot% % output parameter :%      "rs_seq_l_ns": the reference_signal sequence needed by 3GPP TDD-LTE% %   note : %      the generalization of the reference signal sequence%       can be found in Ref.36.211.850 %**************************************************************************% N_cell_id= 17;% N_CP = 1;% ns=1;% l=4;%parameter needed,can be found in LTE reference 36.211-850N_RB_DL_MAX=110;%generation of gold sequence(生成Gold序列)gold_seq = gen_gold_seq(N_cell_id,N_CP,ns,l);%generation of reference sequence（生成参考序列）rs_seq_l_ns = zeros(1,N_RB_DL_MAX * 2);for m = 1 : N_RB_DL_MAX * 2    rs_seq_l_ns(m)=(1/sqrt(2)) * ( (1-2*gold_seq(2*m-1)) + (1-2*gold_seq(2*m))*j );end function gold_seq_out = gen_gold_seq (N_cell_id,N_CP,ns,l)% *************************************************************************% Function Description: (v1.0---20090428 by )% This function is used for the progress of generation of gold sequence % that is needed by cell_specific reference signal in 3GPP LTE.% % usage :%      gold_seq_out = gen_gold_seq (N_cell_id,N_CP,ns,l)% % input parameter（输入参数）:%      "N_cell_id" : Physical layer cell identity.%      "N_CP" : For normal CP,N_CP=1; for extended CP,N_CP=0;%      "ns" : The slot number within a radio frame%      "l" : The OFDM symbol number within the slot% % output parameter :%      "gold_seq_out": the gold_seq needed by 3GPP TDD-LTE,%     it starts at c(1601) and with a length of (N_RB_DL_MAX+1)*4% note : %      the initialization of the m-sequence can be found in 36.211.850.%**************************************************************************% N_cell_id= 17;% N_CP = 1;% ns=1;% l=4;%parameter needed,can be found in LTE reference 36.211-850N_RB_DL_MAX=110;NC=1600;%generation of the first m-sequence x1.(产生第一个m序列x1)% the length of x1 needed at least is N_RB_DL_MAX*4+NCx1=zeros(1,(N_RB_DL_MAX+1)*4+NC);x1(1)=1;%the values of x1(32)---x1((N_RB_DL_MAX+1)*4+NC-31)for k = 1 : (N_RB_DL_MAX+1) * 4 + NC - 31    x1(k+31)=mod((x1(k+3)+x1(k)),2);endx1;%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%generation of the second m-sequence x2.（产生第二个m序列x2）% the length of x2 needed at least is (N_RB_DL_MAX)*4+NCx2=zeros(1,(N_RB_DL_MAX+1)*4+NC);%the initialization of the first 31 values of x2;x2(1) = N_CP;for k=1:9    x2(k+1)=bitget(N_cell_id,k); %information of cell id endother21bits=(7*(ns+1)+l+1)*(N_cell_id*2+1);for k=1:21    x2(k+10)=bitget(other21bits,k); %initialization of the other 21 bits;end%the values of x2(32)---x2((N_RB_DL_MAX+1)*4+NC-31)for k=1N_RB_DL_MAX+1)*4+NC-31    x2(k+31)=mod((x2(k+3)+x2(k+2)+x2(k+1)+x2(k)),2);endx2;%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%the generation of the gold sequence cn;gold_seq_out=zeros(1,(N_RB_DL_MAX+1)*4);for k=1N_RB_DL_MAX+1)*4    gold_seq_out(k)=mod((x1(k+NC)+x2(k+NC)),2);end%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

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