function [quad,inphase]=down_converter(received,fc,fs,T,cut_off,order)%   [quad,inphase]=down_converter(received,fc,fs,T,cut_off,order)%%	Output:%	quad		- Quadrature component of the received signal, in baseband%	inphase		- Inphase component of the received signal, in baseband%	%   Input:%   received    - Received signal, in passband %   fc          - Carrier frequency%   fs          - Sampling frequency%   T           - Symbol period%   cut_off     - Cut off frequency for the lowpass filter%   order       - Order of the lowpass filter%%   Short Theoretical Background for the Function:%   %   Downconverts the received passband signal to a baseband signal which%   is lowpass filtered and split into a quadrature and an inphase component %   The function low_pass is used for lowpass filtering%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%     %%% Function part of simulation for Space-Time%%% coding project, group Grey-2001.%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%   Author:  Fredrik Hansson%   Date:    2001-03-20%   Version: 1.0%   Revision (Name & Date):%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%oversamp = fs*T;t = 0:T/oversamp:(length(received)*T-T)/oversamp; % timescaleri = received.*(2*cos(-2*pi*fc*t));      % downconversion, still containing                                         % high frequency componentsrq = received.*(2*sin(-2*pi*fc*t));      % downconversion, still containing                                         % high frequency componentsinphase = low_pass(cut_off,order,ri);    % The inphase component onlyquad    = low_pass(cut_off,order,rq);    % The quadrature component only