% [X] FEC
% [X] pilot insertion and removal
% [ ] delay on parity and DSSS carriers
-% [ ] pilot based phase est
+% [X] pilot based phase est
% [ ] uncoded and coded frame sync
% [ ] timing estimation, RN filtering, carrier FDM
% Symbol rate processing for tx side (modulator)
-function [tx_symb tx_bits prev_sym_tx] = tx_symbol_rate(sim_in, tx_bits, code_param, prev_sym_tx)
+function [tx_symb tx_bits prev_sym_tx] = symbol_rate_tx(sim_in, tx_bits, code_param, prev_sym_tx)
ldpc_code = sim_in.ldpc_code;
+ rate = sim_in.ldpc_code_rate;
framesize = sim_in.framesize;
- rate = sim_in.rate;
Nsymbrow = sim_in.Nsymbrow;
Nsymbrowpilot = sim_in.Nsymbrowpilot;
Nc = sim_in.Nc;
endfunction
-% main test function
+% init function for symbol rate processing
-function sim_out = ber_test(sim_in)
- Fs = 8000;
+function sim_in = symbol_rate_init(sim_in)
+ sim_in.Fs = Fs = 8000;
modulation = sim_in.modulation;
verbose = sim_in.verbose;
Np = sim_in.Np; % number of pilots to use
Ns = sim_in.Ns; % step size between pilots
ldpc_code = sim_in.ldpc_code;
- sim_in.rate = rate = sim_in.ldpc_code_rate;
+ rate = sim_in.ldpc_code_rate;
- bps = 2;
+ sim_in.bps = bps = 2;
sim_in.Nsymb = Nsymb = framesize/bps;
sim_in.Nsymbrow = Nsymbrow = Nsymb/Nc;
assert(Npilotsframe == floor(Nsymbrow/Ns), "Npilotsframe must be an integer");
- prev_sym_tx = qpsk_mod([0 0])*ones(1,Nc*Nchip);
- prev_sym_rx = qpsk_mod([0 0])*ones(1,Nc*Nchip);
+ sim_in.prev_sym_tx = qpsk_mod([0 0])*ones(1,Nc*Nchip);
+ sim_in.prev_sym_rx = qpsk_mod([0 0])*ones(1,Nc*Nchip);
- rx_symb_buf = zeros(3*Nsymbrow, Nc*Nchip);
- rx_pilot_buf = zeros(3*Npilotsframe,Nc*Nchip);
- tx_bits_buf = zeros(1,2*framesize);
+ sim_in.rx_symb_buf = zeros(3*Nsymbrow, Nc*Nchip);
+ sim_in.rx_pilot_buf = zeros(3*Npilotsframe,Nc*Nchip);
+ sim_in.tx_bits_buf = zeros(1,2*framesize);
% pilot sequence is used for phase and amplitude estimation, and frame sync
pilot(:,c) = [ones(1,floor(Npilotsframe/2)) -ones(1,ceil(Npilotsframe/2))]';
end
sim_in.pilot = pilot;
- tx_pilot_buf = [pilot; pilot; pilot];
+ sim_in.tx_pilot_buf = [pilot; pilot; pilot];
% Init LDPC --------------------------------------------------------------------
modulation2 = 'QPSK';
mapping = 'gray';
- demod_type = 0;
- decoder_type = 0;
- max_iterations = 100;
+ sim_in.demod_type = 0;
+ sim_in.decoder_type = 0;
+ sim_in.max_iterations = 100;
code_param = ldpc_init(rate, framesize, modulation2, mod_order, mapping);
code_param.code_bits_per_frame = framesize;
code_param.symbols_per_frame = framesize/bps;
-
- ldpc_errors_log = []; ldpc_Nerrs_log = [];
+ sim_in.code_param = code_param;
else
- rate = 1;
+ sim_in.rate = 1;
+ end
+endfunction
+
+
+function [rx_symb rx_bits rx_symb_linear amp_linear amp_ phi_ prev_sym_rx sim_in] = symbol_rate_rx(sim_in, s_ch, prev_sym_rx)
+ framesize = sim_in.framesize;
+ Nsymb = sim_in.Nsymb;
+ Nsymbrow = sim_in.Nsymbrow;
+ Nsymbrowpilot = sim_in.Nsymbrowpilot;
+ Nc = sim_in.Nc;
+ Npilotsframe = sim_in.Npilotsframe;
+ Ns = sim_in.Ns;
+ Np = sim_in.Np;
+ Nchip = sim_in.Nchip;
+ modulation = sim_in.modulation;
+ pilot = sim_in.pilot;
+ rx_symb_buf = sim_in.rx_symb_buf;
+ rx_pilot_buf = sim_in.rx_pilot_buf;
+ tx_pilot_buf = sim_in.tx_pilot_buf;
+ verbose = sim_in.verbose;
+
+ % demodulate stage 1
+
+ for r=1:Nsymbrowpilot
+ for c=1:Nc*Nchip
+ rx_symb(r,c) = s_ch(r, c);
+ if strcmp(modulation,'dqpsk')
+ tmp = rx_symb(r,c);
+ rx_symb(r,c) *= conj(prev_sym_rx(c)/abs(prev_sym_rx(c)));
+ prev_sym_rx(c) = tmp;
+ end
+ end
+ end
+
+ % strip out pilots
+
+ rx_symb_pilot = rx_symb;
+ rx_symb = zeros(Nsymbrow, Nc*Nchip);
+ rx_pilot = zeros(Npilotsframe, Nc*Nchip);
+
+ for p=1:Npilotsframe
+ % printf("%d %d %d %d %d\n", (p-1)*Ns+1, p*Ns, (p-1)*(Ns+1)+2, p*(Ns+1), (p-1)*(Ns+1)+1);
+ rx_symb((p-1)*Ns+1:p*Ns,:) = rx_symb_pilot((p-1)*(Ns+1)+2:p*(Ns+1),:);
+ rx_pilot(p,:) = rx_symb_pilot((p-1)*(Ns+1)+1,:);
+ end
+
+ % buffer three frames of symbols (and pilots) for phase recovery
+
+ rx_symb_buf(1:2*Nsymbrow,:) = rx_symb_buf(Nsymbrow+1:3*Nsymbrow,:);
+ rx_symb_buf(2*Nsymbrow+1:3*Nsymbrow,:) = rx_symb;
+ rx_pilot_buf(1:2*Npilotsframe,:) = rx_pilot_buf(Npilotsframe+1:3*Npilotsframe,:);
+ rx_pilot_buf(2*Npilotsframe+1:3*Npilotsframe,:) = rx_pilot;
+ sim_in.rx_symb_buf = rx_symb_buf;
+ sim_in.rx_pilot_buf = rx_pilot_buf;
+
+ % pilot assisted phase estimation and correction of middle frame in rx symb buffer
+
+ rx_symb = rx_symb_buf(Nsymbrow+1:2*Nsymbrow,:);
+
+ phi_ = zeros(Nsymbrow, Nc*Nchip);
+ amp_ = ones(Nsymbrow, Nc*Nchip);
+
+ for c=1:Nc*Nchip
+
+ if verbose > 2
+ printf("phi_ : ");
+ end
+
+ for r=1:Nsymbrow
+ st = Npilotsframe+1+floor((r-1)/Ns) - floor(Np/2) + 1;
+ en = st + Np - 1;
+ phi_(r,c) = angle(sum(tx_pilot_buf(st:en,1)'*rx_pilot_buf(st:en,c)));
+ amp_(r,c) = abs(tx_pilot_buf(st:en,1)'*rx_pilot_buf(st:en,c))/Np;
+ %amp_(r,c) = abs(rx_symb(r,c));
+ if verbose > 2
+ printf("% 4.3f ", phi_(r,c))
+ end
+ rx_symb(r,c) *= exp(-j*phi_(r,c));
+ end
+
+ if verbose > 2
+ printf("\nrx_symb: ");
+ for r=1:Nsymbrow
+ printf("% 4.3f ", angle(rx_symb(r,c)))
+ end
+ printf("\nindexes: ");
+ for r=1:Nsymbrow
+ st = Npilotsframe+1+floor((r-1)/Ns) - floor(Np/2) + 1;
+ en = st + Np - 1;
+ printf("%2d,%2d ", st,en)
+ end
+ printf("\npilots : ");
+ for p=1:3*Npilotsframe
+ printf("% 4.3f ", angle(rx_pilot_buf(p,c)));
+ end
+ printf("\n\n");
+ end
+ end
+
+ % de-spread
+
+ for r=1:Nsymbrow
+ for c=Nc+1:Nc:Nchip*Nc
+ rx_symb(r,1:Nc) = rx_symb(r,1:Nc) + rx_symb(r,c:c+Nc-1);
+ amp_(r,1:Nc) = amp_(r,1:Nc) + amp_(r,c:c+Nc-1);
+ end
+ end
+
+ % demodulate stage 2
+
+ rx_symb_linear = zeros(1,Nsymb);
+ amp_linear = zeros(1,Nsymb);
+ rx_bits = zeros(1, framesize);
+ for c=1:Nc
+ for r=1:Nsymbrow
+ i = (c-1)*Nsymbrow + r;
+ rx_symb_linear(i) = rx_symb(r,c);
+ amp_linear(i) = amp_(r,c);
+ rx_bits((2*(i-1)+1):(2*i)) = qpsk_demod(rx_symb(r,c));
+ end
end
+endfunction
+
+
+function sim_out = ber_test(sim_in)
+ sim_in = symbol_rate_init(sim_in);
+
+ Fs = sim_in.Fs;
+ Rs = sim_in.Rs;
+ Ntrials = sim_in.Ntrials;
+ verbose = sim_in.verbose;
+ plot_scatter = sim_in.plot_scatter;
+ framesize = sim_in.framesize;
+ bps = sim_in.bps;
+
+ Esvec = sim_in.Esvec;
+ ldpc_code = sim_in.ldpc_code;
+ rate = sim_in.ldpc_code_rate;
+ code_param = sim_in.code_param;
+ tx_bits_buf = sim_in.tx_bits_buf;
+ Nsymb = sim_in.Nsymb;
+ Nsymbrow = sim_in.Nsymbrow;
+ Nsymbrowpilot = sim_in.Nsymbrowpilot;
+ Nc = sim_in.Nc;
+ Npilotsframe = sim_in.Npilotsframe;
+ Ns = sim_in.Ns;
+ Np = sim_in.Np;
+ Nchip = sim_in.Nchip;
+ modulation = sim_in.modulation;
+ pilot = sim_in.pilot;
+ prev_sym_tx = sim_in.prev_sym_tx;
+ prev_sym_rx = sim_in.prev_sym_rx;
+ rx_symb_buf = sim_in.rx_symb_buf;
+ tx_pilot_buf = sim_in.tx_pilot_buf;
+ rx_pilot_buf = sim_in.rx_pilot_buf;
+
+ hf_sim = sim_in.hf_sim;
+ nhfdelay = sim_in.hf_delay_ms*Rs/1000;
+ hf_mag_only = sim_in.hf_mag_only;
[spread spread_2ms hf_gain] = init_hf_model(Fs, Rs, Nsymbrowpilot*Ntrials);
phi_log = [];
amp_log = [];
+ ldpc_errors_log = []; ldpc_Nerrs_log = [];
+
Terrsldpc = Tbitsldpc = Ferrsldpc = 0;
% init HF channel
tx_bits = round(rand(1,framesize));
end
- [s_ch tx_bits prev_sym_tx] = tx_symbol_rate(sim_in, tx_bits, code_param, prev_sym_tx);
+ [s_ch tx_bits prev_sym_tx] = symbol_rate_tx(sim_in, tx_bits, code_param, prev_sym_tx);
tx_bits_buf(1:framesize) = tx_bits_buf(framesize+1:2*framesize);
tx_bits_buf(framesize+1:2*framesize) = tx_bits;
s_ch = s_ch + noise;
- % demodulate stage 1
-
- for r=1:Nsymbrowpilot
- for c=1:Nc*Nchip
- rx_symb(r,c) = s_ch(r, c);
- if strcmp(modulation,'dqpsk')
- tmp = rx_symb(r,c);
- rx_symb(r,c) *= conj(prev_sym_rx(c)/abs(prev_sym_rx(c)));
- prev_sym_rx(c) = tmp;
- end
- end
- end
+ [rx_symb rx_bits rx_symb_linear amp_linear amp_ phi_ prev_sym_rx sim_in] = symbol_rate_rx(sim_in, s_ch, prev_sym_rx);
- % strip out pilots
-
- rx_symb_pilot = rx_symb;
- rx_symb = zeros(Nsymbrow, Nc*Nchip);
- rx_pilot = zeros(Npilotsframe, Nc*Nchip);
-
- for p=1:Npilotsframe
- % printf("%d %d %d %d %d\n", (p-1)*Ns+1, p*Ns, (p-1)*(Ns+1)+2, p*(Ns+1), (p-1)*(Ns+1)+1);
- rx_symb((p-1)*Ns+1:p*Ns,:) = rx_symb_pilot((p-1)*(Ns+1)+2:p*(Ns+1),:);
- rx_pilot(p,:) = rx_symb_pilot((p-1)*(Ns+1)+1,:);
- end
-
- % buffer three frames of symbols (and pilots) for phase recovery
-
- rx_symb_buf(1:2*Nsymbrow,:) = rx_symb_buf(Nsymbrow+1:3*Nsymbrow,:);
- rx_symb_buf(2*Nsymbrow+1:3*Nsymbrow,:) = rx_symb;
- rx_pilot_buf(1:2*Npilotsframe,:) = rx_pilot_buf(Npilotsframe+1:3*Npilotsframe,:);
- rx_pilot_buf(2*Npilotsframe+1:3*Npilotsframe,:) = rx_pilot;
-
- % pilot assisted phase estimation and correction of middle frame in rx symb buffer
-
- rx_symb = rx_symb_buf(Nsymbrow+1:2*Nsymbrow,:);
-
- phi_ = zeros(Nsymbrow, Nc*Nchip);
- amp_ = ones(Nsymbrow, Nc*Nchip);
- if nn > 2
- for c=1:Nc*Nchip
- if verbose > 2
- printf("phi_ : ");
- end
- for r=1:Nsymbrow
- st = Npilotsframe+1+floor((r-1)/Ns) - floor(Np/2) + 1;
- en = st + Np - 1;
- phi_(r,c) = angle(sum(tx_pilot_buf(st:en,1)'*rx_pilot_buf(st:en,c)));
- amp_(r,c) = abs(tx_pilot_buf(st:en,1)'*rx_pilot_buf(st:en,c))/Np;
- %amp_(r,c) = abs(rx_symb(r,c));
- if verbose > 2
- printf("% 4.3f ", phi_(r,c))
- end
- rx_symb(r,c) *= exp(-j*phi_(r,c));
- end
- if verbose > 2
- printf("\nrx_symb: ");
- for r=1:Nsymbrow
- printf("% 4.3f ", angle(rx_symb(r,c)))
- end
- printf("\nindexes: ");
- for r=1:Nsymbrow
- st = Npilotsframe+1+floor((r-1)/Ns) - floor(Np/2) + 1;
- en = st + Np - 1;
- printf("%2d,%2d ", st,en)
- end
- printf("\npilots : ");
- for p=1:3*Npilotsframe
- printf("% 4.3f ", angle(rx_pilot_buf(p,c)));
- end
- printf("\n\n");
- end
- end
- phi_log = [phi_log; phi_];
- end
-
- % de-spread
-
- for r=1:Nsymbrow
- for c=Nc+1:Nc:Nchip*Nc
- rx_symb(r,1:Nc) = rx_symb(r,1:Nc) + rx_symb(r,c:c+Nc-1);
- amp_(r,1:Nc) = amp_(r,1:Nc) + amp_(r,c:c+Nc-1);
- end
- end
-
- if nn > 2
- amp_log = [amp_log; amp_];
- end
-
- % demodulate stage 2
-
- rx_symb_linear = zeros(1,Nsymb);
- amp_linear = zeros(1,Nsymb);
- rx_bits = zeros(1, framesize);
- for c=1:Nc
- for r=1:Nsymbrow
- i = (c-1)*Nsymbrow + r;
- rx_symb_linear(i) = rx_symb(r,c);
- amp_linear(i) = amp_(r,c);
- rx_bits((2*(i-1)+1):(2*i)) = qpsk_demod(rx_symb(r,c));
- end
- end
+ phi_log = [phi_log; phi_];
+ amp_log = [amp_log; amp_];
% Wait until we have 3 frames to do pilot assisted phase estimation
% Optionally LDPC decode
if ldpc_code
- detected_data = ldpc_dec(code_param, max_iterations, demod_type, decoder_type, ...
+ detected_data = ldpc_dec(code_param, sim_in.max_iterations, sim_in.demod_type, sim_in.decoder_type, ...
rx_symb_linear, min(100,EsNo), amp_linear);
error_positions = xor( detected_data(1:framesize*rate), tx_bits_buf(1:framesize*rate) );
Nerrs = sum(error_positions);
[m1 n1] = size(phi_log);
phi_x = [];
- phi_x_counter = Nsymbrowpilot + 1;
+ phi_x_counter = 1;
p = Ns;
for r=1:m1
if p == Ns
projects / freetel-svn-tracking.git / commitdiff