% Version 2
%
% TODO:
-% [ ] refactor with states
-% [ ] remove commented out globals
-% [ ] tfdmdv works
+% [X] refactor with states
+% [X] remove commented out globals
+% [X] tfdmdv works
% [ ] fdmdv_ut works
% reqd to make sure we get same random bits at mod and demod
rand('state',1);
randn('state',1);
-#{
-
-% Constants
-
-
-global Fs = 8000; % sample rate in Hz
-global T = 1/Fs; % sample period in seconds
-global Rs;
- Rs = 50; % symbol rate in Hz
-global Nc; % number of carriers
-if exist("NumCarriers") == 0
- Nc = 14;
-else
- Nc = NumCarriers;
-end
-global Nb;
- Nb = 2; % Bits/symbol for PSK modulation
-global Rb;
- Rb = Nc*Rs*Nb; % bit rate
-global M = Fs/Rs; % oversampling factor
-global Nsym = 6; % number of symbols to filter over
-global Fsep;
- Fsep = 75; % Separation between carriers (Hz)
-global Fcentre = 1500; % Centre frequency, Nc/2 carriers below this, N/c carriers above (Hz)
-global Nt = 5; % number of symbols we estimate timing over
-global P = 4; % oversample factor used for rx symbol filtering
-global Nfilter = Nsym*M;
-global Nfiltertiming = M+Nfilter+M;
-alpha = 0.5;
-global snr_coeff;
- snr_coeff = 0.9;% SNR est averaging filter coeff
-global Nph;
- Nph = 9; % number of symbols to estimate phase over
- % must be odd number as we take centre symbol
-global Nsync_mem = 6
-global sync_uw = [1 -1 1 -1 1 -1];
-
-% root raised cosine (Root Nyquist) filter
-
-global gt_alpha5_root;
-gt_alpha5_root = gen_rn_coeffs(alpha, T, Rs, Nsym, M);
-
-% rx decimation filter
-
-global Nrxdec;
- Nrxdec=31;
-global rxdec_coeff;
- rxdec_coeff = fir1(Nrxdec-1, 0.25);
-
-if 0
- % tmp code to plot freq resp. 20dB attn of any aliases should be fine
- % not real sensitive to in-band attn, e.g. outer tones a dB down should be OK
- % in terms of BER
- figure(1)
- [h,f]=freqz(rxdec,1,4000);
- hdB=20*log10(abs(h));
- plot(hdB(1:1200))
- grid
-end
-
-% Converts gray code to natural binary
-
-global m4_gray_to_binary = [
- bin2dec("00")
- bin2dec("01")
- bin2dec("11")
- bin2dec("10")
- ];
-global m8_gray_to_binary = [
- bin2dec("000")
- bin2dec("001")
- bin2dec("011")
- bin2dec("010")
- bin2dec("111")
- bin2dec("110")
- bin2dec("100")
- bin2dec("101")
- ];
-
-% Convert natural binary to gray code
-
-global m4_binary_to_gray = [
- bin2dec("00")
- bin2dec("01")
- bin2dec("11")
- bin2dec("10")
- ];
-
-global m8_binary_to_gray = [
- bin2dec("000")
- bin2dec("001")
- bin2dec("011")
- bin2dec("010")
- bin2dec("110")
- bin2dec("111")
- bin2dec("101")
- bin2dec("100")
- ];
-
-% temp logging stuff
-#}
-
% Functions ----------------------------------------------------
endfunction
-if 0
-% Initialise ----------------------------------------------------
-
-global pilot_bit;
-pilot_bit = 0; % current value of pilot bit
-
-global tx_filter_memory;
-tx_filter_memory = zeros(Nc+1, Nfilter);
-global rx_filter_memory;
-rx_filter_memory = zeros(Nc+1, Nfilter);
-
-global rx_fdm_mem;
- rx_fdm_mem = zeros(1,Nfilter+M);
-
-% phasors used for up and down converters
-
-global freq;
- freq = zeros(Nc+1,1);
-global freq_pol;
- freq_pol = zeros(Nc+1,1);
-for c=1:Nc/2
- %carrier_freq = (-Nc/2 - 1 + c)*Fsep + Fcentre;
- carrier_freq = (-Nc/2 - 1 + c)*Fsep;
- freq_pol(c) = 2*pi*carrier_freq/Fs;
- freq(c) = exp(j*freq_pol(c));
-end
-for c=floor(Nc/2)+1:Nc
- %carrier_freq = (-Nc/2 + c)*Fsep + Fcentre;
- carrier_freq = (-Nc/2 + c)*Fsep;
- freq_pol(c) = 2*pi*carrier_freq/Fs;
- freq(c) = exp(j*freq_pol(c));
-end
-
-%freq_pol(Nc+1) = 2*pi*Fcentre/Fs;
-freq_pol(Nc+1) = 2*pi*0/Fs;
-freq(Nc+1) = exp(j*freq_pol(Nc+1));
-
-global fbb_rect;
- fbb_rect = exp(j*2*pi*Fcentre/Fs);
-global fbb_phase_tx;
- fbb_phase_tx = 1;
-global fbb_phase_rx;
- fbb_phase_rx = 1;
-global rxdec_lpf_mem;
- rxdec_lpf_mem = zeros(1,Nrxdec-1+M);
-global Q=M/4;
-
-% Spread initial FDM carrier phase out as far as possible. This
-% helped PAPR for a few dB. We don't need to adjust rx phase as DQPSK
-% takes care of that.
-
-global phase_tx;
-phase_tx = ones(Nc+1,1);
-phase_tx = exp(j*2*pi*(0:Nc)/(Nc+1));
-%phase_tx = exp(j*2*pi*(0:Nc)/4);
-%phase_tx(Nc+1) = -1;
-global phase_rx;
-phase_rx = ones(Nc+1,1);
-
-% Freq offset estimator constants
-
-global Mpilotfft = 256;
-
-global Npilotcoeff; % number of pilot LPF coeffs
- Npilotcoeff = 30;
-global pilot_coeff;
- pilot_coeff = fir1(Npilotcoeff-1, 200/(Fs/2))';% 200Hz LPF
-global Npilotbaseband = Npilotcoeff + M + M/P; % number of pilot baseband samples reqd for pilot LPF
-global Npilotlpf; % number of symbols we DFT pilot over, pilot est window
- Npilotlpf = 4*M;
-
-% pilot LUT, used for copy of pilot at rx
-
-global pilot_lut;
-pilot_lut = generate_pilot_lut();
-global pilot_lut_index;
- pilot_lut_index = 1;
-global prev_pilot_lut_index;
- prev_pilot_lut_index = 3*M+1;
-
-% Freq offset estimator states
-
-global pilot_baseband1;
-global pilot_baseband2;
-pilot_baseband1 = zeros(1, Npilotbaseband); % pilot baseband samples
-pilot_baseband2 = zeros(1, Npilotbaseband); % pilot baseband samples
-global pilot_lpf1
-global pilot_lpf2
-pilot_lpf1 = zeros(1, Npilotlpf); % LPF pilot samples
-pilot_lpf2 = zeros(1, Npilotlpf); % LPF pilot samples
-
-% Timing estimator states
-
-global rx_filter_mem_timing;
-rx_filter_mem_timing = zeros(Nc+1, Nt*P);
-global rx_baseband_mem_timing;
-rx_baseband_mem_timing = zeros(Nc+1, Nfiltertiming);
-
-% Test bit stream constants
-
-global Ntest_bits;
- Ntest_bits = Nc*Nb*4; % length of test sequence
-global test_bits;
- test_bits = rand(1,Ntest_bits) > 0.5;
-
-% Test bit stream state variables
-
-global current_test_bit = 1;
-current_test_bit = 1;
-global rx_test_bits_mem;
-rx_test_bits_mem = zeros(1,Ntest_bits);
-
-% Experimental phase estimator states ----------------------
-
-global rx_symbols_mem;
-rx_symbols_mem = zeros(Nc+1, Nph);
-global prev_phase_offsets;
-prev_phase_offsets = zeros(Nc+1, 1);
-global phase_amb;
-phase_amb = zeros(Nc+1, 1);
-end
projects / freetel-svn-tracking.git / commitdiff