t_seq_gen.m

小区初搜为GSM系统中的一个关键过程

function T_SEQ = T_SEQ_gen(TRAINING)
%
% T_SEQ_GEN:
%           This function generates the MSK-mapped version of the 
%           training sequence used in the GSMsim package.
%
% SYNTAX:   T_SEQ = T_SEQ_gen(TRAINING)
%
% INPUT:    TRAINING: The training sequence represented as bits. (0's and 1's)
%
% OUTPUT:     T_SEQ: A MSK-mapped representation of the 26/36/64 bits long
%                    training sequence.
%
% SUB_FUNC: None
%
% WARNINGS: First MSK symbol is set to 1. This may be a problem!!!
%
% TEST(S):  Result is verified against those reported by 95gr870T
%
% AUTOR:    wuguangfu   20070820
%

Lburst = 148;
L = length(TRAINING);
data = [1 zeros(1,(Lburst-L)/2) TRAINING zeros(1,(Lburst-L)/2)]; %First MSK symbol is set to 1.

% INTERMEDIATE VECTORS FOR DATA PROCESSING 
%
a = zeros(1,Lburst);

for n = 1+1 : Lburst+1
  a(n-1) = xor( data(n),data(n-1) );   
end

% MAKE A POLAR VERSION OF TRAINING
a = 1 - 2.*a;

% THIS IS A CHOICE, AND IT MAY BE WRONG!!!!!!
T_SEQ(1) = 1;
for n = 2 : Lburst+1
  T_SEQ(n)=j*a(n-1)*T_SEQ(n-1);%From this,we know the beginning of the MSK symbol is the second. 
end

T_SEQ = T_SEQ((Lburst-L)/2+2 : Lburst-(Lburst-L)/2+1);