generateultable.m

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%**************************************************************************
%  802.16-2004 OFDMA PHY - Sub-channel to tile mapper
%
%    Description: Maps the sub-channel index to the set of tiles that
%                 belongs to that sub-channel according to 8.4.6.2
%
%    Parameters:  subAllocVector: vector of allocated sub-channel numbers
%                 UL_IDCell: ID cell(5 LSB) used as permutation number
%                 Nsubcarriers: number of data subcarriers for one
%                               subchannel (48)
%                 TilesPerSubchannel: number of tiles in one subchannel(6)
%                 FFT_size: number of FFT points
%
%    Output:    dataOVec: matrix of data carrier locations in the middle symbol
%                         of every slot, that are allocated to each subchannel.
%                         Each row corresponds to a different sub-channel.
%               dataPVec: matrix of data carrier locations in the first/third
%                         symbol of every slot, that are allocated to each subchannel.
%                         Each row corresponds to a different sub-channel.
%               pilotLocVec: matrix of pilot carrier locations in the first/third
%                            symbol of every slot, that are allocated to each subchannel.
%                            Each row corresponds to a different sub-channel.
%               rotationOffset: Vector of initial rotation values that are used to rotate
%                               data symbols before mapping them to data carriers.
%
%    Functions:
%                N/A
%
%    Data Files:
%                N/A
%
%***************************************************************************

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%  Property of Freescale
%  Freescale Confidential Proprietary
%  Freescale Copyright (C) 2005 All rights reserved
%  ----------------------------------------------------------------------------
%  $RCSfile: GenerateULTable.m.rca $
%  $Revision: 1.4 $
%  $Date: Mon Dec 11 16:48:12 2006 $
%  Target: Matlab
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

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

function [dataOVec, dataPVec, pilotLocVec, rotationOffset] = GenerateULTable(subAllocVector,UL_PermBase,Nsubcarriers,TilesPerSubchannel,FFT_size)

% the permutation that determines the mapping of a subchannel to a
% physical set of tiles
switch FFT_size
    case 2048
        TilePermutation = [6,48,58,57,50,1,13,26,46,44,30,3,27,53,22,18,61,7,55,36,45,37,52,15,40,2,20,4,34,31,10,5,41,9,69,63,21,11,12,19,68,56,43,23,25,39,66,42,16,47,51,8,62,14,33,24,32,17,54,29,67,49,65,35,38,59,64,28,60,0];
    case 1024
        TilePermutation = [11,19,12,32,33,9,30,7,4,2,13,8,17,23,27,5,15,34,22,14,21,1,0,24,3,26,29,31,20,25,16,10,6,28,18];
    case 512
        TilePermutation = [11,15,10,2,12,9,8,14,16,4,0,5,13,3,6,7,1];
    case 128
        TilePermutation = 0:23;
end

% number of tiles in each group (a total of 6 groups of 70 contiguous
% tiles each)
Nsubchannels = length(TilePermutation);

Nused = length(subAllocVector);

tileMatrix = zeros(Nused,TilesPerSubchannel);

% compute tile locations according to 8.4.6.2.2 for each subchannel in
% the segment
% tileMatrix(i,j) is a value between 0 and 419
for i=1:Nused
    for j=1:TilesPerSubchannel
        % tileMatrix(i,j)= Nsubchannels*(j-1)+mod((TilePermutation(mod((subAllocVector(i)+j-1),Nsubchannels)+1)+UL_IDCell),Nsubchannels);
        tileMatrix(i,j)= Nsubchannels*(j-1)+mod((TilePermutation(mod((subAllocVector(i)+j-1),Nsubchannels)+1)+UL_PermBase),Nsubchannels);
    end
end

for i=1:Nused
    carrierVec = tileMatrix(i,:)*4;
    dataOVec(i,:) = sort([carrierVec,carrierVec+1,carrierVec+2,carrierVec+3])+1;
    dataPVec(i,:) = sort([carrierVec+1,carrierVec+2])+1;
    pilotLocVec(i,:) = sort([carrierVec,carrierVec+3])+1;

    % determine the offset at which to map data to carriers
    carrierOffset = mod(subAllocVector(i)*13,Nsubcarriers);
    % instead of rotating the subcarrier mapping, rotate the data carriers
    if (carrierOffset>0)
        rotationOffset(i) = Nsubcarriers-carrierOffset+1;
    else
        rotationOffset(i) = 0;
    end
end