基于matlab的判决反馈的均衡器

【核心代码】

% The DFEcator
% General Information
% ===================
% The DFEcator is a tool for design of minimum mean square error (MMSE) and
% adaptive decision feedback equalizers (DFE) based on
% The Bergulator (refer to http://www.backhoe.ee.cornell.edu/BERG).  Both
% baud-spaced equalizers (BS) and T/2 fractionally-spaced (FS) DFEs may be 
% designed to equalize complex, additive white gaussian noise channels (AWGN)
% for various choices of parameters.  For MMSE designs some of these choices
% include:
% 
% * channel (coefficients, source and SNR)
% * forward and feedback filter lengths 
%   OR total number of coefficients 
% * cursor delay (for non-blind equalization) 
% * processing delay (delay required for processing decisions before they
%                     are sent to the feedback filter)
% * bias 
% 
% For adaptive designs, we also have:
%
% * forward and feedback filter initializations
% * adaptive algorithm (LMS, decision-direction, CMA) for both linear IIR
%   and DFE structures
% * forward and feedback filter step-size
%
% Figures displaying information about the designs may be accessed through 
% toggle buttons on the left side of the screen.  Variables containing
% results of designs and experiments may be accessed by typing
% 
%                             dfec_global
%
% at the Matlab prompt. Type
% 
%                           help dfec_global 
%
% for a description of each variable. 
%
%
% There are four main pieces of The DFEcator: channel, equalizer and 
% adaptation parameter boxes, and action buttons.  A brief description of
% each follows:
%
%
% CHANNEL PARAMETERS
% ==================
% "Channel Type"
% -------------- 
% * "8-tap" and "3-tap" select demonstration channels.
% * "Custom" allows typing in channel taps in the 
%   editing box or typing the name of a variable 
%   residing in the Matlab workspace.
%   WARNING: avoid using variable names which are
%            global to The DFEcator.  Check for the
%            list of variables by typing "dfec_global"
%            and using the "who" command
% * "File" allows typing in the name of a .mat file 
%   containing the vector "c" of channel coefficients. 
%
%     
% "Source"
% --------
% Includes several real and complex valued sources of several sizes, 
% i.e. PAM, QAM
%
%
% "dB SNR"
% -------- 
%  * Enter signal to noise ratio in dBs. 
%  * Type "Inf" for no noise. 
%  * Can type range of SNRs, e.g. 10:2:20 for SER vs. SNR waterfall curves
%    Figures display results of MMSE design for the highest value of the SNR
%    vector. 
%                   
%
% "Normalize"
% -----------
% * Normalizes channel to unit (l_2) norm when toggled on.
%
%
% "Display"
% ---------
% * Displays channel impulse and frequency responses when toggled on.
% 
%
%
% EQUALIZER PARAMETERS
% ====================
% "Nf Nd or [Nf,Nd]"
% ------------------
% * Type [Nf Nd] for length of forward and feedback filters,
%   e.g. [4 3] for a length Nf=4 forward filter and 
%   length Nd=3 feedback filter.
% * Type single integer M for a total number of parameters.
%   The DFEcator will compute all possible MMSE designs for each
%   combination [Nf Nd] (over other parameters such as SNR and delay)
%   such that Nf Nd=M.
% * If the Nf Nd format is used adaptation capabilities are turned
%   off since filter lengths are unspecified.
% 
%
% "Cursor Delay"
% --------------
% * "Opt" optimizes MMSE design over every possible cursor delay choice.
% * "Max" swith matches cursor to maximum channel tap.
% * "Center Spike" computes transmission delay as sum of delays introduced
%   by largest channel tap and a center spike in forward filter tap delay
%   line
% * "End" computes the transmission delay as sum of delays introduced 
%   by largest channel tap and a spike at the end of forward filter
%   tap delay line
% * "Range" allows selection of range of delays in the "Range" edit box.
% 
%
% "Spacing"
% ---------
% Switches between baud- ("BSE") and T/2 fractionally-spaced ("FSE")
% channels/equalizers.
%
%
% "Unbiased"
% ----------
% Switch between biased ("Biased") and unbiased ("Unbiased") designs.
% An unbiased design constrains the MMSE cursor to unity while a biased design
% minimizes MSE without constraints.  
%
%
% "Proc. Delay"
% ------------- 
% Processing time required to make decisions on symbols.  Must be greater
% than zero.  The default is one (1) baud interval. 
%
% 
%
% ADAPTATION PARAMETERS
% =====================
% "Initialization"
% ---------------- 
% * "Zero" sets initial forward and feedback filters to zero.
% * "Center spike" sets initial forward equalizer to have a single, center
%   spike and feedback filter to zero.
% * "Double spike" sets initial forward equalizer to have double, center
%   spikes and feedback filter to zero.
% * "DFE-MMSE" sets filters to MMSE-DFE design filters.  The "Design!" button
%   should be pressed in advance to compute these filters. 
% * "IIR-MMSE" sets filters to linear truncated Wiener filters.  Filter
%   lengths are changed to a feedback filter matching the channel memory
%   and a forward filter which is at least as long as the channel memory
% * "End spike" sets initial forward equalizer to have a single 
%   spike at the end of the tap-delay line and feedback filter is set to zero.
% * "Previous" sets filters to the final settings of the previous adaptation.
% * "Custom" allows typing in the edit boxes "f0" and "d0" initial 
%   coefficients or variable names residing in the Matlab workspace.
%   WARNING: avoid using variable names which are
%            global to The DFEcator.  Check for the
%            list of variables by typing "dfec_global"
%            and using the "who" command
% * "From file" allows typing in a .mat file containing variables f0 for 
%   forward filter taps and d0 for feedback filter taps.
% 
%
% "Algorithm"
% -----------
% * "DFE-LMS" uses the least mean squares algorithm with training sequence 
%   delayed by the choice of delay in the EQUALIZER PARAMETERS box to update
%   the DFE structure.
% * "DFE-DD" uses decision direction to update DFE structure with training 
%   and blind data. 
% * "DFE-CMA" uses the constant modulus algorithm to update DFE structure using
%   training and blind data. 
% * "DFE-LMS DD" uses LMS during training and decision-direction in blind mode. 
% * "DFE-LMS CMA" uses LMS during training and CMA in blind mode. 
% * "IIR-LMS" adapts forward and linear AR feedback filters with training 
%    and LMS. 
% * "IIR-DD" adapts forward and linear AR feedback filters with 
%    decision direction. 
% * "IIR-CMA" adapts forward and linear AR feedback filters with CMA.
% * "IIR-LMS DD" uses LMS during training and decision-direction in blind mode. 
% * "IIR-LMS CMA" uses LMS during training and CMA in blind mode. 
% 
% "Exact gradient"
% ----------------
% * Toggle on to use an exact gradient during IIR adaptation and off
%   to use Feintuch updates.  Has no effect during DFE adaptation.
%
% 
% "[Tr,Bl,Reps] or file"
% ----------------------
% * Format of transmitted sequence or file name.  If internal data used, 
%   "Tr" sets the length of a training block, "Bl" sets the length of a 
%   blind data block and "Reps" sets how many of these training and data 
%   blocks will be transmitted.  If external data used, type in 
%   .mat file as detailed below in "Data".
%
%
% "Data"
% ------
% * "Simulation" creates "Reps" different blocks of training and blind data.
% * "Sim. - Loops" repeats first block of training and blind data "Reps" times.
% * "From file" - allows user to type in name of a .m file with blind and
%    training data.  Requires variables:
%               o  column vector "a" with source symbols 
%               o  column vector "r" of received T-spaced data for BSE case and
%                  two column vectors "ra" and "rb" of received T-spaced data 
%                  for FSE case
%               o  row vector "Lsim" with three entries [Tr,Bl,Reps]
%   
%
%
% "Stepsize [Tr,Bl]"
% ------------------
% * For each filter, enter a pair of stepsizes, i.e. [muf1,muf2] and
%   [mud1,mud2].  The first entry indicates the stepsize used during 
%   trained mode and the second entry is for blind mode.
% * Enter 0 if a particular filter should stay fixed in time.
%
%
%
% ACTION BUTTONS
% ==============
% "Design!"
% ---------
% Press button to update design once a set of parameters is selected.
% If a wide range of parameters is selected (for example, optimization over
% a large total number of filter coefficients and choice of delay and many
% SNRs) computations may be intensive and require a long time.  NOTE: for
% this reason, figures are NOT updated automatically once parameters are
% changed.  They are only update once "Design!" is pressed and parameters
% are recalculated.
%
%
% "MMSE Imp"
% ----------
% Impulse responses of filters and combinations of filters and channel.
%
%
% "MMSE Freq" 
% -----------
% Frequency responses of filters and combinations of filters and channel.
%
%
% "MSE vs. Params"
% ----------------
% Figure plots MSE vs. filter length & delay parameters.  Three different
% plots may be displayed according to settings:
% 
% * If the filter length choice is set to Nf Nd=M and a range of delays
%   is selected with the "Range" or the "Opt" options the "MSE vs. Params" 
%   figure is a three-dimensional surface of MSEs over (Nf,delay) parameter 
%   space (1<=Nf<=M).  The third parameter, Nd, may be derived from Nd=M-Nf.
%   The mouse can be used to rotate the surface for better views. 
% 
% * If the format [Nf Nd] is used for filter lengths, and a range of delays is 
%   selected with the "Range" or the "Opt" options the "MSE vs. Params" 
%   figure is a curve of MSE for each possible delay.
%
% * If the filter length choice is set to Nf Nd=M but the cursor delay is
%   set to "Max" (matching the channel cursor) then a curve of MSE is 
%   plotted for each Nf, 1<=Nf<=M.
% 
% Note that these figures are plotted for the highest value of the SNR.
% 
% 
% "MMSE Cluster"
% --------------
% Cluster plot of MMSE design (optimized over all parameters) for selected 
% source and (highest) SNR. 
%
%
% "Error Propagation"
% -------------------
% Hard and soft decision errors as well as noise filtered through
% forward equalizer for 1000 transmitted symbols for MMSE design (optimized
% over all parameters) for selected source and (highest) SNR.
% Zooming is set on by default.  To move the legends around turn zoom off
% by typing "zoom off" at the Matlab prompt.
%
%
% "SER Curves"
% ------------
% Symbol error rate (SER) vs. SNR for MMSE design (optimized 
% over all parameters) for selected source and (highest) SNR.
%
%
% "Adapt!"
% --------
% Adapts filters using choice of algorithm, step-sizes, duration and 
% initialization.
%
% 
% "Trajectories"
% --------------
% Displays evolution of filter taps over time.
%
% 
% "Adaptation Error"
% ------------------
% Displays adaptation error associated with particular choice of algorithm.
% Certain algorithms have separate error criteria for feedforward and
% feedback filters.
% 
% 
%
% "Ad. Clus."
% ------------------
% Evolution of (adaptation) cluster plot in time. 
%
%
% "Fin. Clus."
% ------------------
% Cluster plot associated with final equalizer.
%
%
% "Final Imp"
% ------------------
% Impulse responses of filters and combinations of filters and channel
% resulting from adaptation.
%
%
% "Final Freq"
% ------------------
% Frequency responses of filters and combinations of filters and channel
% resulting from adaptation.
%
%
% "Help"
% ------------------
% Helps.
%
%
% "Quit"
% ------------------
% Quits.
%
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%   The DFEcator written by:    Raul A. Casas                           %
%%                               raulc@ee.cornell.edu                    %
%%                               Blind Equalization Research Group       %
%%                               (http://backhoe.ee.cornell.edu/BERG/)   %
%%                               Cornell University                      %
%%                               February 1998                           %
%%                                                                       %
%%                               Copyright 1998-2000 Cornell University  % 
%%                                                                       %
%%   last updated 03/30/99                                               %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

function [] = DFEcator();
dfec_global; 
ui_private_global;


% Advise use of dfec_global to look
% at variables
disp('Type "dfec_global" at prompt to look at design variables'); 
disp('(use "who" command). Type "help dfec_global for descriptions.'); 

%%%%%%%%%%%%%%%%%%%
% Declare figures %
%%%%%%%%%%%%%%%%%%%
% Declare output figure numbers and clear them
fig_chan  =  1;
fig_freq  =  2;
fig_imp   =  3;
fig_mse   =  4;
fig_ser   =  5;
fig_cluster   =  6;
fig_ep    =  7;
fig_fimp  =  8;
fig_ffreq =  9;
fig_acluster  = 10;
fig_fcluster  = 11;
fig_aerr  = 12;
fig_traj  = 13;
if ishandle(fig_imp),   delete(fig_imp);   end;
if ishandle(fig_freq),  delete(fig_freq);  end;
if ishandle(fig_mse),   delete(fig_mse);   end;
if ishandle(fig_ser),   delete(fig_ser);   end;
if ishandle(fig_cluster),   delete(fig_cluster);   end;
if ishandle(fig_ep),    delete(fig_ep);    end;
if ishandle(fig_chan),  delete(fig_chan);  end;
if ishandle(fig_fimp),  delete(fig_fimp);  end;
if ishandle(fig_ffreq), delete(fig_ffreq); end;
if ishandle(fig_acluster),  delete(fig_acluster);  end;
if ishandle(fig_fcluster),  delete(fig_fcluster);  end;
if ishandle(fig_aerr),  delete(fig_aerr);  end;
if ishandle(fig_traj),  delete(fig_traj);  end;


%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Allocate control window %
%%%%%%%%%%%%%%%%%%%%%%%%%%%
if exist('fig_menu'), if ishandle(fig_menu), delete(fig_menu); end; end;
fig_menu = figure('IntegerHandle', 'off', 'Name', 'The DFEcator',...
                  'NumberTitle', 'off', 'MenuBar', 'none', 'Resize', 'off');
                  
pos = get(fig_menu, 'Position');
set(fig_menu, 'Position', [pos(1) 100 pos(2)-300 440 720]);
clf;


%%%%%%%%%%%%%%%%%%%%%%
% Channel Parameters %
%%%%%%%%%%%%%%%%%%%%%%
uicontrol('Style', 'frame', 'Position',[170 500 250 200]); 
uicontrol('Style', 'text', 'Position', [180 670 160 20], 'String',...
          'CHANNEL PARAMETERS');

uicontrol('Style', 'text', 'Position', [180 640 100 20], 'String',...
          'Channel Type');
h_chan = uicontrol('Style', 'popupmenu', 'Position', [180 620 100 20],...
                   'String', '8-tap|3-tap|Custom|From file',...
                   'Callback', 'ui_params,ui_chan');

uicontrol('Style', 'text', 'Position', [180 580 100 25], 'String',...
          'Coefficients');
h_coefs = uicontrol('Style', 'edit', 'Position', [180 560 140 25],...
                    'BackgroundColor', [1 1 1], 'Callback',...
                    'ui_params,ui_chan');

h_norm = uicontrol('Style', 'checkbox', 'Position', [180 520 100 20],...
                   'String', 'Normalize',  'Value', 1, 'Callback',...
                   'ui_params,ui_chan');

h_resp = uicontrol('Style', 'checkbox', 'Position', [330 520 80 20],...
                   'String', 'Display', 'Callback', 'ui_chan');

uicontrol('Style', 'text', 'Position', [330 640 75 25], 'String',...
          'Source');
h_source = uicontrol('Style', 'popupmenu', 'Position', [330 620 85 20],...
                   'String',... 
                   ['BPSK|4-PAM|8-PAM|16-PAM|32-PAM|QPSK',...
                   '|16-QAM|64-QAM|256-QAM|1024-QAM'],...
                   'Callback', 'ui_params');

uicontrol('Style', 'text', 'Position', [340 580 50 25 ], 'String', 'dB SNR');
h_SNR = uicontrol('Style', 'edit', 'Position', [340 560 50 25],...
                    'String', '30', 'BackgroundColor', [1 1 1],... 
                    'Callback', 'ui_params');

%%%%%%%%%%%%%%%%%%%%%%%%
% Equalizer Parameters %
%%%%%%%%%%%%%%%%%%%%%%%%
uicontrol('Style', 'frame', 'Position', [170 280 250 200]);
uicontrol('Style', 'text', 'Position', [180 450 180 20], 'String',...
          'EQUALIZER PARAMETERS');

uicontrol('Style', 'text', 'Position', [180 420 100 25], 'String',...
          'Nf Nd or [Nf,Nd]');
h_len = uicontrol('Style', 'edit', 'Position', [180 400 100 25],...
                  'String', '[32 8]', 'BackgroundColor', [1 1 1],...
                  'Callback', 'ui_params');

uicontrol('Style', 'text', 'Position', [180 370 80 20], 'String', 'Spacing');
h_spa = uicontrol('Style', 'popupmenu', 'Position', [180 350 80 20],...
                    'String', 'BSE|FSE', 'Callback', 'ui_params,ui_chan');

h_bias = uicontrol('Style', 'checkbox', 'Position', [180 300 80 20],...
                   'String', 'Unbiased', 'Callback', 'ui_params');


uicontrol('Style', 'text', 'Position', [330 420 80 20], 'String',... 
          'Cursor Delay');
h_deltype = uicontrol('Style', 'popupmenu', 'Position', [330 400 80 20],...
                    'String', 'Opt|Max|End|Center Spike|Range',...
                    'Callback', 'ui_params');

uicontrol('Style', 'text', 'Position', [330 370 80 20], 'String', 'Range');
h_del = uicontrol('Style', 'edit', 'Position', [330 350 80 25],...
                  'BackgroundColor', [1 1 1], 'String', '1',...
                  'Callback', 'ui_params');

uicontrol('Style', 'text', 'Position', [330 320 80 20], 'String',... 
          'Proc. Delay');
h_proc = uicontrol('Style', 'edit', 'Position', [330 300 60 25],...
                  'BackgroundColor', [1 1 1], 'String', '1',...
                  'Callback', 'ui_params');


%%%%%%%%%%%%%%%%%%%%%%%%%
% Adaptation Parameters %
%%%%%%%%%%%%%%%%%%%%%%%%%
uicontrol('Style', 'frame', 'Position', [170 20 250 240]);
uicontrol('Style', 'text', 'Position', [180 230 180 20], 'String',...
          'ADAPTATION PARAMETERS');


uicontrol('Style', 'text', 'Position', [180 205 110 20], 'String',...
          'Algorithm');
h_alg = uicontrol('Style', 'popupmenu', 'Position', [180 185 110 20],...
'String', ['DFE-LMS|DFE-DD|DFE-CMA|DFE-LMS DD|DFE-LMS CMA|IIR-LMS|IIR-DD|IIR-CMA|IIR-LMS DD|IIR-LMS CMA'],'Callback', 'ui_params');

h_reg = uicontrol('Style', 'checkbox', 'Position', [300 185 100 20],...
                   'String', 'Exact gradient',  'Value', 1, 'Callback',...
                   'ui_params,ui_chan');


uicontrol('Style', 'text', 'Position', [180 145 75 20], 'String',...
          'Initialization');
h_init = uicontrol('Style', 'popupmenu', 'Position', [180 125 75 20],...
     'String', ['Zero|Center Spike|Double Spike|DFE-MMSE|IIR-MMSE|End Spike|Previous|Custom|From file'], 'Callback', 'ui_params');

uicontrol('Style', 'text', 'Position', [255 145 40 20], 'String',...
          'f0');
h_f0 = uicontrol('Style', 'edit', 'Position', [285 145 120 25],...
                  'BackgroundColor', [1 1 1],...
                  'Callback', 'ui_params');

uicontrol('Style', 'text', 'Position', [255 125 40 20], 'String',...
          'd0');
h_d0 = uicontrol('Style', 'edit', 'Position', [285 125 120 25],...
                  'BackgroundColor', [1 1 1],...
                  'Callback', 'ui_params');


uicontrol('Style', 'text', 'Position', [180 80 30 20], 'String',...
          'Data');
h_data = uicontrol('Style', 'popupmenu', 'Position', [215 85 90 20],...
     'String', ['Simulation|Sim.-Loops|From file'],...
     'Callback', 'ui_params');


uicontrol('Style', 'text', 'Position', [180 55 120 20], 'String',...
          '[Tr,Bl,Reps] or file');
h_sim  = uicontrol('Style', 'edit', 'Position', [180 30 120 25],...
                  'String', '[100 900 10]', 'BackgroundColor', [1 1 1],...
                  'Callback', 'ui_params');


uicontrol('Style', 'text', 'Position', [330 70 80 20], 'String',...
          'Stepsize [Tr,Bl]');
uicontrol('Style', 'text', 'Position', [300 45 30 20], 'String',...
          'muf');
h_muf = uicontrol('Style', 'edit', 'Position', [330 45 80 25],...
                  'String', '[1e-2,0]', 'BackgroundColor', [1 1 1],...
                  'Callback', 'ui_params');

uicontrol('Style', 'text', 'Position', [300 25 30 20], 'String',...
          'mud');
h_mud = uicontrol('Style', 'edit', 'Position', [330 25 80 25],...
                  'String', '[1e-2,0]', 'BackgroundColor', [1 1 1],...
                  'Callback', 'ui_params');


%%%%%%%%%%%%%%%%%
% Text messages %
%%%%%%%%%%%%%%%%%
h_msg = uicontrol('Style', 'text', 'Position', [10 20 140 20],...
                  'BackgroundColor', [0.8 0.8 0.8], 'String',...
                  'click a button...');


%%%%%%%%%%%%%%%%%%
% Action Buttons %
%%%%%%%%%%%%%%%%%%
h_design = uicontrol('Style', 'pushbutton', 'Position', [20 670 130 30],...
                  'Callback', 'ui_design', 'String', 'Design!');
h_imp = uicontrol('Style', 'checkbox', 'Position', [20 630 130 30],...
                  'Callback', 'ui_imp', 'String', 'MMSE Imp');
h_freq = uicontrol('Style', 'checkbox', 'Position', [20 590 130 30],...
                  'Callback', 'ui_freq', 'String', 'MMSE Freq');
h_mse = uicontrol('Style', 'checkbox', 'Position', [20 550 130 30],...
                  'Callback', 'ui_mse', 'String', 'MSE vs Params');
h_cluster = uicontrol('Style', 'checkbox', 'Position', [20 510 130 30],...
                  'Callback', 'ui_cluster', 'String', 'MMSE Cluster');
h_ep= uicontrol('Style', 'checkbox', 'Position', [20 470 130 30],...
                  'Callback', 'ui_ep', 'String', 'Error Propagation');
h_ser = uicontrol('Style', 'checkbox', 'Position', [20 430 130 30],...
                  'Callback', 'ui_ser', 'String', 'SER Curves');

h_adapt = uicontrol('Style', 'pushbutton', 'Position', [20 320 130 30],...
                  'Callback', 'ui_adapt', 'String', 'Adapt!');
h_traj = uicontrol('Style', 'checkbox', 'Position', [20 280 130 30],...
                  'Callback', 'ui_traj', 'String', 'Trajectories');
h_aerr = uicontrol('Style', 'checkbox', 'Position', [20 240 130 30],...
                  'Callback', 'ui_aerr', 'String', 'Adaptation Error');
h_acluster = uicontrol('Style', 'checkbox', 'Position', [20 200 60 30],...
                  'Callback', 'ui_acluster', 'String', 'Ad. Clus.');
h_fcluster = uicontrol('Style', 'checkbox', 'Position', [90 200 60 30],...
                  'Callback', 'ui_fcluster', 'String', 'Fin. Clus.');
h_fimp = uicontrol('Style', 'checkbox', 'Position', [20 160 130 30],...
                  'Callback', 'ui_fimp', 'String', 'Final Imp');
h_ffreq = uicontrol('Style', 'checkbox', 'Position', [20 120 130 30],...
                  'Callback', 'ui_ffreq', 'String', 'Final Freq');

h_help = uicontrol('Style', 'pushbutton', 'Position', [20 70 60 30],...
                  'Callback', 'helpwin dfecator', 'String', 'Help');
h_quit = uicontrol('Style', 'pushbutton', 'Position', [90 70 60 30],...
                  'Callback', 'ui_quit', 'String', 'Quit');


set(fig_menu, 'HandleVisibility', 'off');

ui_params;
ui_design;