Files
imdd_silas/Classes/04_DSP/Equalizer/FFE_DCremoval_adaptive_mu.m
2026-06-22 22:58:58 +02:00

412 lines
15 KiB
Matlab

classdef FFE_DCremoval_adaptive_mu < handle
% FFE variant for MPI/DC-removal experiments.
% With dc_buffer_len <= 1, ffe_buffer_len <= 1 and no smoothing, this
% follows FFE.m semantics so MPI-reduction changes can be isolated.
properties
sps
order
e
e_tr
error
len_tr
mu_tr
epochs_tr
adaption_technique
dd_mode
mu_dd
epochs_dd
dd_len_fraction
mu_dc
e_dc
P
dc_buffer_len
adaptive_mu_mode
ffe_buffer_len
smoothing_buffer_length
smoothing_buffer_update
constellation
decide
save_debug = 0;
debug_struct
optmize_mus = 0;
mu_optimization
mu_optimization_iter = 0;
end
methods
function obj = FFE_DCremoval_adaptive_mu(options)
arguments(Input)
options.sps = 2;
options.order = 15;
options.len_tr = 4096;
options.mu_tr = 0;
options.epochs_tr = 5;
options.adaption_technique adaption_method = adaption_method.lms;
options.dd_mode = 1;
options.mu_dd = 1e-5;
options.epochs_dd = 5;
options.dd_len_fraction = 0.25;
options.mu_dc = 0.05;
options.dc_buffer_len = 1;
options.adaptive_mu_mode = 1;
options.ffe_buffer_len = 1;
options.smoothing_buffer_length = 0;
options.smoothing_buffer_update = 0;
options.decide = false;
options.save_debug = 0;
options.optmize_mus = 0;
end
assert(options.dc_buffer_len >= 0);
assert(options.ffe_buffer_len >= 0);
assert(options.smoothing_buffer_length >= 0);
if options.smoothing_buffer_length > 0
assert(options.smoothing_buffer_update > 0);
end
fn = fieldnames(options);
for n = 1:numel(fn)
obj.(fn{n}) = options.(fn{n});
end
obj.e = zeros(obj.order,1);
obj.e_dc = 0;
obj.error = 0;
obj.dc_buffer_len = floor(obj.dc_buffer_len);
obj.ffe_buffer_len = floor(obj.ffe_buffer_len);
obj.smoothing_buffer_length = floor(obj.smoothing_buffer_length);
obj.smoothing_buffer_update = floor(obj.smoothing_buffer_update);
end
function [X,Noi] = process(obj, X, D)
X = X.normalize("mode","rms");
obj.constellation = unique(D.signal);
obj.e_dc = 0;
delta = 0.05;
obj.P = (1/delta) * eye(obj.order);
if obj.optmize_mus
obj.optimizeMus(X.signal,D.signal);
obj.e = zeros(obj.order,1);
obj.e_dc = 0;
obj.P = (1/delta) * eye(obj.order);
end
training = 1;
showviz = 0;
obj.equalize(X.signal,D.signal,obj.mu_tr,obj.epochs_tr,obj.len_tr,training,showviz);
obj.e_tr = obj.e;
n = X.length;
training = 0;
if obj.dd_mode
n_dd = obj.ddLength(n);
obj.equalize(X.signal,D.signal,obj.mu_dd,obj.epochs_dd,n_dd,training,showviz);
end
[signal,decision] = obj.applyCurrentTaps(X.signal,n);
if obj.decide
X.signal = decision;
else
X.signal = signal;
end
X.fs = D.fs;
lbdesc = [num2str(obj.order),' tap FFE'];
X = X.logbookentry(lbdesc);
Noi = X;
Noi = X - D;
end
function [y,d_hat] = equalize(obj,x,d,mu,epochs,N,training,showviz)
arguments
obj
x
d
mu
epochs
N
training
showviz = 0 %#ok<INUSD>
end
x = [zeros(floor(obj.order/2),1); x; zeros(obj.order,1)];
lambda = mu;
if training
mask = ones(obj.order,1);
else
mask = zeros(obj.order,1);
mask(900:end) = 1;
mask(ceil(length(obj.e)/2)) = 1;
end
mask = ones(obj.order,1);
always_ideal_decision = 0;
grad = 0;
weight = 0;
update = 0;
if mu == 0 || (~obj.dd_mode && ~training)
epochs = 1;
end
dc_buffer_enabled = obj.mu_dc ~= 0 && obj.dc_buffer_len > 1;
adaptive_dc_enabled = dc_buffer_enabled && obj.adaptive_mu_mode;
if dc_buffer_enabled
e_dc_buffer = NaN(obj.dc_buffer_len,1);
end
ffe_buffer_enabled = ~training && obj.ffe_buffer_len > 1 && ...
obj.adaption_technique ~= adaption_method.rls;
if ffe_buffer_enabled
grad_buffer = NaN(obj.order,obj.ffe_buffer_len);
end
if obj.smoothing_buffer_length > 0
smoothing_buffer = zeros(1,obj.smoothing_buffer_length);
smoothing_mean = 0;
end
P_err = 0;
alpha = 0.98;
err_prev = 0;
gamma_dc = 1e-6;
mu_min = 1e-6;
mu_max = 3e-1;
for epoch = 1 : epochs
symbol = 0;
for sample = 1 : obj.sps : N
symbol = symbol + 1;
if obj.smoothing_buffer_length > 0
smoothing_buffer = circshift(smoothing_buffer,1,2);
smoothing_buffer(1) = x(sample);
if mod(symbol,obj.smoothing_buffer_update) == 0
smoothing_mean = mean(smoothing_buffer);
end
x(sample:sample+obj.sps-1) = x(sample:sample+obj.sps-1) - smoothing_mean;
end
U = x(obj.order+sample-1:-1:sample);
y(symbol,1) = obj.e_dc + (obj.e.*mask).' * U;
if training
d_hat(symbol,1) = d(symbol);
else
if ~always_ideal_decision
[~,symbol_idx] = min(abs(y(symbol) - obj.constellation));
d_hat(symbol,1) = obj.constellation(symbol_idx);
else
d_hat(symbol,1) = d(symbol);
end
end
err(symbol) = d_hat(symbol) - y(symbol); %#ok<AGROW>
true_err(symbol) = y(symbol) - d(symbol); %#ok<AGROW,NASGU>
if training || obj.dd_mode
switch obj.adaption_technique
case adaption_method.lms
weight = mu;
grad = err(symbol) * U;
update = grad * weight;
case adaption_method.nlms
normU = (U.'*U) + eps;
weight = mu / normU;
grad = err(symbol) * U;
update = grad * weight;
case adaption_method.rls
denom = lambda + U.' * obj.P * U;
k = (obj.P * U) / denom;
update = k * err(symbol);
end
if ffe_buffer_enabled
grad_buffer = circshift(grad_buffer,1,2);
grad_buffer(:,1) = update;
if mod(symbol,obj.ffe_buffer_len) == 0
obj.e = obj.e + mean(grad_buffer,2,"omitnan");
end
else
obj.e = obj.e + update;
end
if obj.adaption_technique == adaption_method.rls
obj.P = (1/lambda) * (obj.P - k * (U.' * obj.P));
end
if obj.mu_dc ~= 0
if adaptive_dc_enabled
delta_mu = gamma_dc * err(symbol) * err_prev * (U.'*U);
obj.mu_dc = min(max(obj.mu_dc + delta_mu,mu_min),mu_max);
err_prev = err(symbol);
P_err = alpha*P_err + (1-alpha)*err(symbol)^2;
mu_dc_eff = obj.mu_dc / (P_err + eps);
else
mu_dc_eff = obj.mu_dc;
end
if dc_buffer_enabled
e_dc_buffer = circshift(e_dc_buffer,1);
e_dc_buffer(1) = obj.e_dc + mu_dc_eff * err(symbol);
if mod(symbol,obj.dc_buffer_len) == 0
obj.e_dc = median(e_dc_buffer,"omitnan");
end
else
obj.e_dc = obj.e_dc + mu_dc_eff * err(symbol);
end
end
end
if obj.save_debug
obj.debug_struct.error(epoch,symbol) = err(symbol) * err(symbol)';
if training
obj.debug_struct.error_tr(epoch,symbol) = err(symbol) * err(symbol)';
obj.debug_struct.update_tr(epoch,symbol) = update.'*update ./ rms(obj.e);
end
end
% obj.error(epoch,symbol) = err(symbol) * err(symbol)';
end
end
end
function [y,d_hat] = applyCurrentTaps(obj,x,N)
x = [zeros(floor(obj.order/2),1); x; zeros(obj.order,1)];
for sample = 1 : obj.sps : N
symbol = (sample - 1) / obj.sps + 1;
U = x(obj.order+sample-1:-1:sample);
y(symbol,1) = obj.e_dc + obj.e.' * U;
[~,symbol_idx] = min(abs(y(symbol) - obj.constellation));
d_hat(symbol,1) = obj.constellation(symbol_idx);
end
end
function N_dd = ddLength(obj,N)
if isempty(obj.dd_len_fraction) || obj.dd_len_fraction <= 0 || obj.dd_len_fraction >= 1
N_dd = N;
return
end
N_dd = floor(N * obj.dd_len_fraction);
N_dd = max(obj.sps,N_dd);
N_dd = min(N,N_dd);
end
function optimizeMus(obj,x,d)
switch obj.adaption_technique
case adaption_method.lms
mu_range = [1e-5, 1e-2];
case adaption_method.nlms
mu_range = [1e-3, 5e-1];
case adaption_method.rls
mu_range = [0.98, 0.99999];
end
mu_dc_range = [1e-5, 1e-1];
mu_tr_var = optimizableVariable("mu_tr",mu_range,"Transform","log");
vars = mu_tr_var;
if obj.dd_mode
vars = [vars, optimizableVariable("mu_dd",mu_range,"Transform","log")];
end
optimize_mu_dc = obj.mu_dc ~= 0;
if optimize_mu_dc
vars = [vars, optimizableVariable("mu_dc",mu_dc_range,"Transform","log")];
end
obj.mu_optimization_iter = 0;
obj.mu_optimization = bayesopt(@(p)obj.muObjective(p,x,d),vars, ...
"MaxObjectiveEvaluations",10, ...
"AcquisitionFunctionName","expected-improvement-plus", ...
"IsObjectiveDeterministic",false, ...
"Verbose",0, ...
"PlotFcn",[]);
obj.mu_tr = obj.mu_optimization.XAtMinObjective.mu_tr;
if obj.dd_mode
obj.mu_dd = obj.mu_optimization.XAtMinObjective.mu_dd;
end
if optimize_mu_dc
obj.mu_dc = obj.mu_optimization.XAtMinObjective.mu_dc;
end
objective_db = 10*log10(obj.mu_optimization.MinObjective);
if obj.dd_mode && optimize_mu_dc
fprintf("\nFFE_DCremoval_adaptive_mu opt done: mu_tr=%9.3e, mu_dd=%9.3e, mu_dc=%9.3e, MSE=%9.3e, MSE_dB=%7.2f dB\n", ...
obj.mu_tr,obj.mu_dd,obj.mu_dc,obj.mu_optimization.MinObjective,objective_db);
elseif obj.dd_mode
fprintf("\nFFE_DCremoval_adaptive_mu opt done: mu_tr=%9.3e, mu_dd=%9.3e, MSE=%9.3e, MSE_dB=%7.2f dB\n", ...
obj.mu_tr,obj.mu_dd,obj.mu_optimization.MinObjective,objective_db);
elseif optimize_mu_dc
fprintf("\nFFE_DCremoval_adaptive_mu opt done: mu_tr=%9.3e, mu_dc=%9.3e, MSE=%9.3e, MSE_dB=%7.2f dB\n", ...
obj.mu_tr,obj.mu_dc,obj.mu_optimization.MinObjective,objective_db);
else
fprintf("\nFFE_DCremoval_adaptive_mu opt done: mu_tr=%9.3e, MSE=%9.3e, MSE_dB=%7.2f dB\n", ...
obj.mu_tr,obj.mu_optimization.MinObjective,objective_db);
end
end
function objective = muObjective(obj,params,x,d)
old_debug = obj.save_debug;
old_mu_dc = obj.mu_dc;
obj.save_debug = 1;
if isprop(params,"mu_dc")
obj.mu_dc = params.mu_dc;
end
obj.e = zeros(obj.order,1);
obj.e_dc = 0;
obj.P = (1/0.05) * eye(obj.order);
obj.debug_struct = struct();
obj.equalize(x,d,params.mu_tr,obj.epochs_tr,obj.len_tr,1,0);
if obj.dd_mode
obj.equalize(x,d,params.mu_dd,obj.epochs_dd,obj.ddLength(numel(x)),0,0);
objective = mean(obj.debug_struct.error(end,:),"omitnan");
else
objective = mean(obj.debug_struct.error_tr(end,:),"omitnan");
end
if ~isfinite(objective)
objective = inf;
end
objective_db = 10*log10(objective);
obj.mu_optimization_iter = obj.mu_optimization_iter + 1;
optimize_mu_dc = isprop(params,"mu_dc");
if obj.dd_mode && optimize_mu_dc
fprintf("\rFFE_DCremoval_adaptive_mu opt %02d: mu_tr=%9.3e, mu_dd=%9.3e, mu_dc=%9.3e, MSE=%9.3e, MSE_dB=%7.2f dB", ...
obj.mu_optimization_iter,params.mu_tr,params.mu_dd,params.mu_dc,objective,objective_db);
elseif obj.dd_mode
fprintf("\rFFE_DCremoval_adaptive_mu opt %02d: mu_tr=%9.3e, mu_dd=%9.3e, MSE=%9.3e, MSE_dB=%7.2f dB", ...
obj.mu_optimization_iter,params.mu_tr,params.mu_dd,objective,objective_db);
elseif optimize_mu_dc
fprintf("\rFFE_DCremoval_adaptive_mu opt %02d: mu_tr=%9.3e, mu_dc=%9.3e, MSE=%9.3e, MSE_dB=%7.2f dB", ...
obj.mu_optimization_iter,params.mu_tr,params.mu_dc,objective,objective_db);
else
fprintf("\rFFE_DCremoval_adaptive_mu opt %02d: mu_tr=%9.3e, MSE=%9.3e, MSE_dB=%7.2f dB", ...
obj.mu_optimization_iter,params.mu_tr,objective,objective_db);
end
obj.save_debug = old_debug;
obj.mu_dc = old_mu_dc;
end
end
end