mprbs.m

来自「OFDMA 物理层开发的matlab 源码.飞思卡尔提供.对物理层开发的工程师有」· M 代码 · 共 92 行

function [PNCode]= mPRBS(CellId,FrameNr,NFFTUsed)
% FPUL Frame Start of IEEE 802.16-2005 (WiMAX, OFDMA only)
% Input:
%       NFFTUsed    -- Number of FFT carrier
% Output:
%       TileLUT     -- Tile LUT
% Remark:
%
% Matlab 7 Release 14 SP2

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%  Property of Freescale
%  Freescale Confidential Proprietary
%  Freescale Copyright (C) 2005 All rights reserved
%  ----------------------------------------------------------------------------
%  $RCSfile: mPRBS.m.rca $
%  $Revision: 1.5 $
%  $Date: Fri Nov 17 14:20:31 2006 $
%  Target: Matlab
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

%-- Matlab files used by this file
%-- End of list

NumBits = NFFTUsed + 1 + 32;

%Calculate init state
if (bitand(CellId,16) > 0 )  %hex2dec('10')=16
    PrbsState  = 1;
else
    PrbsState  = 0;
end

if (bitand(CellId,8) > 0)
    PrbsState = bitor(PrbsState,2);
end

if (bitand(CellId,4) > 0)
    PrbsState = bitor(PrbsState,4);
end

if (bitand(CellId,2) > 0)
    PrbsState = bitor(PrbsState,8);
end

if (bitand(CellId,1) > 0)
    PrbsState = bitor(PrbsState,16);  %hex2dec('10')=16
end

PrbsState = bitor(PrbsState,bitshift(3,5));

if (bitand(FrameNr,8) > 0)
    PrbsState = bitor(PrbsState,128); % hex2dec('80')=128
end

if (bitand(FrameNr,4) > 0)
    PrbsState = bitor(PrbsState,256);  %hex2dec('100')=256
end

if (bitand(FrameNr,2) > 0)
    PrbsState = bitor(PrbsState,512);  %hex2dec('200')=512
end

if (bitand(FrameNr,1) > 0)
    PrbsState = bitor(PrbsState,1024);  %hex2dec('400')=1024
end

% generate PN sequence
PRBS_POLY = 5;
for PNIndex=1:NumBits
    X = bitand(PrbsState,PRBS_POLY);
    PrbsState = bitshift(uint16(PrbsState),-1);
    switch X
        case 0
            PN(PNIndex) =  1;
        case 1
            PN(PNIndex) =  -1;
            PrbsState = bitor(PrbsState,1024); %hex2dec('400')=1024
        case 4
            PN(PNIndex) =  1;
            PrbsState = bitor(PrbsState,1024); %hex2dec('400')=1024
        case 5
            PN(PNIndex) =  -1;
        otherwise
            PN(PNIndex) =  1;
    end
end

PNCode = PN;

end