LTE上行链路仿真（基于ITPP库C++语言编写）

#include "stdafx.h" #include "itpp/itcomm.h" #include "uplink.h" #include "channel_estimation.h" using std::cin; using std::cout; using std::endl; using namespace itpp; int main() { CRC_Code crc("CRC-24"); Turbo_Codec turbo; ivec gen(2); QPSK qpsk; OFDM ofdm(N, Ncp); AWGN_Channel awgn_channel; BERC berc; it_file ff; Real_Timer tt; Channel_Specification channel_spec(ITU_Vehicular_A); TDL_Channel channel(channel_spec, Ts); int constraint_length = 4; Sequence_Interleaver<bin> interleaver_in_turbo(inputbit_num_slot + crc_length); Sequence_Interleaver<bin> interleaver1( Mbit); Sequence_Interleaver<double> interleaver2( Mbit); bvec input_bits(inputbits_num_frame); Array<bvec> Slot_bits(slots_per_frame); Array<bvec> Slot_bits_crc(slots_per_frame); Array<bvec> Slot_bits_turboed(slots_per_frame); Array<bvec> Slot_bits_interleaved(slots_per_frame); ivec sequence_interleaver_inturbo; ivec sequence_interleaver; bvec transmit_bits(Mbit_frame); cvec modulated_symb(Mbit_frame/2); Array<cvec> modulated_symb_StoP(SCsymb_frame_useful); Array<cvec> dft_symb(SCsymb_frame_useful); Array<cvec> dft_symb_RS(SCsymb_frame); Array<cvec> maped_symb(SCsymb_frame); Array<cvec> ofdm_modulated_symb(SCsymb_frame); Array<cvec> coeff; cvec receive_symb; cvec receive_symb_awgn; Array<cvec> receive_symb_StoP(SCsymb_frame); Array<cvec> ofdm_demodulated_symb(SCsymb_frame); Array<cvec> fft_symb(SCsymb_frame); Array<cvec> demaped_symb(SCsymb_frame); cvec transmit_symb(SCsymb_frame * (N + Ncp)); Array<cvec> channel_estimated(SCsymb_frame); cvec equilibrium_coefficient_mmse; cvec equilibrium_coefficient_zf; Array<cvec> equalizated_symb(SCsymb_frame); Array<cvec> equalizated_symb_useful(SCsymb_frame_useful); Array<cvec> idft_symb(SCsymb_frame_useful); cvec idft_symb_PtoS(SCsymb_frame_useful * Msc_PUSCH); vec demodulated_symb(Msymb); Array<vec> slot_soft_bits(slots_per_frame); Array<vec> slot_soft_bits_deinterleaved(slots_per_frame); Array<bvec> slot_bits_deturboed(slots_per_frame); Array<bvec> Slot_bits_decrc(slots_per_frame); bvec output_bits(inputbits_num_frame); //generator polynomials gen(0) = 013; gen(1) = 015; //channel channel.set_norm_doppler( norm_doppler); //channel.set_fading_type(Static); channel.set_fading_type(Correlated); //RS cvec reference_signal = 1/sqrt((double)Msc_PUSCH) *fft(qpsk.modulate_bits( randb( 2 * Msc_PUSCH))); //turbo码内交织序列 interleaver_in_turbo.randomize_interleaver_sequence(); sequence_interleaver_inturbo = interleaver_in_turbo.get_interleaver_sequence(); turbo.set_parameters(gen, gen, constraint_length, sequence_interleaver_inturbo); //交织序列 interleaver1.randomize_interleaver_sequence(); sequence_interleaver = interleaver1.get_interleaver_sequence(); interleaver2.set_interleaver_sequence(sequence_interleaver); vec EbN0dB = linspace(0, 20, 3); vec EbN0 = inv_dB(EbN0dB); vec N0 = rate * Eb * pow(EbN0,-1.0); vec bit_error_rate(EbN0dB.length()); vec block_error_rate(EbN0dB.length()); int block_error = 0; cout << "\t\t\tstarting simulation"<<endl; tt.tic(); for (int n=0; n<EbN0dB.length(); n++) { awgn_channel.set_noise(N0(n)); int loop_num = ((int)EbN0dB(n)/5 + 1) * loop_num_base; for(int i=0;i<loop_num;i++) { cout << i << " "; input_bits = randb(inputbits_num_frame); for(int f=0;f<slots_per_frame;f++)//turbo 按每个时隙(资源块)进行 { Slot_bits(f) = input_bits( f*inputbit_num_slot, (f+1)*inputbit_num_slot-1); Slot_bits_crc(f) = crc.encode( Slot_bits(f)); turbo.encode(Slot_bits_crc(f), Slot_bits_turboed(f)); Slot_bits_interleaved(f) = interleaver1.interleave(Slot_bits_turboed(f)); transmit_bits.set_subvector(f * Mbit, Slot_bits_interleaved(f)); } qpsk.modulate_bits( transmit_bits, modulated_symb); int p = 0, q = 0; for(int s=1;s<SCsymb_frame;s++) { /****************************transmit*************************************/ if(s % Nsymb_UL != RS_location) { //SP modulated_symb_StoP(p) = modulated_symb(p * Msc_PUSCH, (p + 1) * Msc_PUSCH - 1); //dft dft_symb(p) = 1/sqrt((double)Msc_PUSCH) *fft( modulated_symb_StoP(p), Msc_PUSCH); dft_symb_RS(s) = dft_symb(p); p++; } else { //add RS dft_symb_RS(s) = reference_signal; } //subcarrier map maped_symb(s) = zeros_c( N); maped_symb(s).set_subvector(map_location, dft_symb_RS(s)); //ofdm modulate ofdm_modulated_symb(s) = ofdm.modulate( maped_symb(s)); //PS transmit_symb.set_subvector(s * (N + Ncp), ofdm_modulated_symb(s)); /****************************transmit*************************************/ } /************************channel and noise********************************/ receive_symb = channel( transmit_symb, coeff); receive_symb = receive_symb.get(0, transmit_symb.length()- 1); receive_symb_awgn = awgn_channel(receive_symb); //receive_symb_awgn = receive_symb; /************************channel and noise********************************/ for(int s=0;s<SCsymb_frame;s++) { //SP receive_symb_StoP(s) = receive_symb_awgn.get(s * (N + Ncp), (s + 1) * (N + Ncp)-1); //ofdm demodulate ofdm_demodulated_symb(s) = ofdm.demodulate(receive_symb_StoP(s)); //subcarrier demap demaped_symb(s) = ofdm_demodulated_symb(s).get(map_location, map_location + Msc_PUSCH - 1); } /**************************************channel estimation**************************/ channel_estimated = channel_estimation(demaped_symb, reference_signal); /**************************************channel estimation**************************/ /************************************receive and detect****************************/ for(int s=0;s<SCsymb_frame;s++) { /************************************FDE***************************************/ //mmse equilibrium_coefficient_mmse =elem_div(conj(channel_estimated(s)) , (elem_mult(channel_estimated(s) , conj(channel_estimated(s))) + N0(n) * ones_c(Msc_PUSCH))); equalizated_symb(s) =elem_mult(demaped_symb(s), equilibrium_coefficient_mmse); //zf //equilibrium_coefficient_zf = elem_div(ones_c(Msc_PUSCH), channel_estimated(s)); //equalizated_symb(s) =elem_mult(demaped_symb(s), equilibrium_coefficient_zf); /************************************FDE***************************************/ if(s % Nsymb_UL != RS_location) { //remove RS equalizated_symb_useful(q) = equalizated_symb(s); //idft idft_symb(q) = sqrt((double)Msc_PUSCH) * ifft(equalizated_symb_useful(q), Msc_PUSCH); //PS idft_symb_PtoS.set_subvector(q * Msc_PUSCH, idft_symb(q)); q++; } } qpsk.demodulate_soft_bits(idft_symb_PtoS, N0(n), demodulated_symb); for(int f=0;f<slots_per_frame;f++)//按每个时隙(资源块)进行 { slot_soft_bits(f) = demodulated_symb.get(f*Mbit, (f+1)*Mbit-1); slot_soft_bits_deinterleaved(f) = interleaver2.deinterleave(slot_soft_bits(f)); turbo.decode(slot_soft_bits_deinterleaved(f), slot_bits_deturboed(f)); if(false == crc.decode(slot_bits_deturboed(f), Slot_bits_decrc(f))) block_error++; output_bits.set_subvector( f*inputbit_num_slot, (f+1)*inputbit_num_slot-1, Slot_bits_decrc(f)); } berc.count(output_bits,input_bits); }//end of i bit_error_rate(n) = berc.get_errorrate(); block_error_rate(n) = (double)block_error / (slots_per_frame*loop_num); berc.clear(); block_error = 0; cout <<"\nsnr = " << EbN0dB(n) << "\t" << "ber = " << bit_error_rate(n); cout << "\t"<< "bler = " << block_error_rate(n) << endl; }//end of n //Save the results to file: ff.open("uplink1_ber.it"); ff << Name("EbN0dB") << EbN0dB; ff << Name("ber") << bit_e