DifferentialMIMO-IdealRayleigh-BER.py

This webpage introduces an API example for the noncohrent scenario, which uses DifferentialMLDSimulator. Other examples are found in DifferentialMLDSimulatorTest.

This example compares the BER performance of the differential BPSK, differential orthogonal space-time block code (DOSTBC), diagonal unitary code (DUC), algebraic differential spatial modulation (ADSM), and differential threaded algebraic space-time (DTAST) schemes. The simulation parameters are given in the table below.

Performance Results

Simulation Parameters

Parameter	Value
Channel	Ideal Rayleigh fading
Number of transmit antennas	\(M=2\)
Number of receive antennas	\(N=2\)
Constellation size	\(L=2,4\)
Transmission rate	\(R=B/T=2/2=1\) [bit/symbol]

Reproducible Code

import sys
import numpy as np
import matplotlib.pyplot as plt
from imtoolkit import Parameters, Modulator, OSTBCode, DiagonalUnitaryCode, ADSMCode, TASTCode, IdealRayleighChannel, DifferentialMLDSimulator

plt.switch_backend('agg')
plt.rcParams['xtick.direction'] = 'in'
plt.rcParams['ytick.direction'] = 'in'
plt.rcParams['markers.fillstyle'] = 'none'

def simulateBER(argstr):
    params = Parameters(argstr)
    if params.code == "symbol":
        codes = np.array(Modulator("PSK", params.L).symbols).reshape(params.L, 1, 1)
    elif params.code == "OSTBC":
        codes = OSTBCode(params.M, "PSK", params.L).codes
    elif params.code == "DUC":
        codes = DiagonalUnitaryCode(params.M, params.L).codes
    elif params.code == "ADSM":
        codes = ADSMCode(params.M, params.mod, params.L).codes
    elif params.code == "TAST":
        codes = TASTCode(params.M, params.Q, params.L).codes

    channel = IdealRayleighChannel(params.ITi, params.M, params.N)
    sim = DifferentialMLDSimulator(codes, channel)
    return sim.simulateBERParallel(params, outputFile=False, printValue=False)

if __name__ == '__main__':
    fig, ax = plt.subplots()
    ax.set_xlabel("SNR [dB]")
    ax.set_ylabel("BER")
    ax.set_xlim(-10, 30)
    plt.ylim(1e-7, 1e0)
    plt.yscale("log")
    ax.tick_params(pad=8)

    ret = simulateBER("BERP_sim=diff_channel=rayleigh_code=symbol_M=1_N=2_T=1_L=2_mod=PSK_ITo=1e3_ITi=1e5_snrfrom=-10.00_to=30.00_len=21")
    ax.plot(ret["snr_dB"], ret["ber"], color="k", marker="s", linestyle="-", label="DBPSK")

    ret = simulateBER("BERP_sim=diff_channel=rayleigh_code=OSTBC_M=2_N=2_T=2_L=2_mod=PSK_ITo=1e3_ITi=1e5_snrfrom=-10.00_to=30.00_len=21")
    ax.plot(ret["snr_dB"], ret["ber"], color="b", marker="o", linestyle="-", label="DOSTBC [1]")

    ret = simulateBER("BERP_sim=diff_channel=rayleigh_code=DUC_M=2_N=2_T=2_L=4_ITo=1e3_ITi=1e5_snrfrom=-10.00_to=30.00_len=21")
    ax.plot(ret["snr_dB"], ret["ber"], color="b", marker="^", linestyle="-", label="DUC [2]")

    ret = simulateBER("BERP_sim=diff_channel=rayleigh_code=ADSM_M=2_N=2_T=2_L=2_mod=PSK_ITo=1e3_ITi=1e5_snrfrom=-10.00_to=30.00_len=21")
    ax.plot(ret["snr_dB"], ret["ber"], color="r", marker="x", linestyle="-", label="ADSM [4]")

    ret = simulateBER("BERP_sim=diff_channel=rayleigh_code=TAST_M=2_Q=1_N=2_T=2_L=2_mod=PSK_ITo=1e3_ITi=1e5_snrfrom=-10.00_to=30.00_len=21")
    ax.plot(ret["snr_dB"], ret["ber"], color="r", marker="+", linestyle="-", label="DTAST [5]")

    handles, labels = ax.get_legend_handles_labels()
    legend = ax.legend(handles, labels, loc="best", frameon=True)
    frame = legend.get_frame()
    frame.set_facecolor('white')
    frame.set_edgecolor('white')

    #plt.show()
    plt.savefig(sys.argv[0].replace(".py", ".svg"))

Related Publications

• [1] S. Alamouti, “A simple transmit diversity technique for wireless communications,” IEEE J. Sel. Areas Commun., vol. 16, no. 8, pp. 1451–1458, 1998.

• [2] B. M. Hochwald and W. Sweldens, “Differential unitary space-time modulation,” IEEE Trans. Commun., vol. 48, no. 12, pp. 2041–2052, 2000.

• [3] R. Rajashekar, N. Ishikawa, S. Sugiura, K. V. S. Hari, and L. Hanzo, “Full-diversity dispersion matrices from algebraic field extensions for differential spatial modulation,” IEEE Trans. Veh. Technol., vol. 66, no. 1, pp. 385–394, 2017.

• [4] R. Rajashekar, C. Xu, N. Ishikawa, S. Sugiura, K. V. S. Hari, and L. Hanzo, “Algebraic differential spatial modulation is capable of approaching the performance of its coherent counterpart,” IEEE Trans. Commun., vol. 65, no. 10, pp. 4260–4273, 2017.

• [5] C. Xu, P. Zhang, R. Rajashekar, N. Ishikawa, S. Sugiura, L. Wang, and L. Hanzo, “Finite-cardinality single-RF differential space-time modulation for improving the diversity-throughput tradeoff,” IEEE Trans. Commun. Press, vol. 67, no. 1, pp. 318–335, 2019.

• [6] C. Xu, R. Rajashekar, N. Ishikawa, S. Sugiura, and L. Hanzo, “Single-RF index shift keying aided differential space-time block coding,” IEEE Trans. Signal Process., vol. 66, no. 3, pp. 773–788, 2018.

• [7] C. Xu, P. Zhang, R. Rajashekar, N. Ishikawa, S. Sugiura, Z. Wang, and L. Hanzo, “Near-perfect finite-cardinality generalized space-time shift keying,” IEEE J. Sel. Areas Commun., in press.

• [8] N. Ishikawa, “IMToolkit: An open-source index modulation toolkit for reproducible research based on massively parallel algorithms,” IEEE Access, vol. 7, pp. 93830–93846, July 2019.