A Tight Upper Bound on the Performance of Iterative Detection and Decoding for Coded Full-Duplex SIMO Systems

In this letter, we investigate a coded full-duplex (FD) bidirectional transceiver based on single-input multiple-output (SIMO). Iterative detection and decoding (IDD) are proposed to mitigate the residual self-interference (SI) remaining after applying passive suppression and two stages of SI cancellation (SIC) filters in analog and digital domains. IDD comprises an adaptive minimum mean-squared error (MMSE) filter with log-likelihood ratio (LLR) demapping, while the soft-in soft-out (SISO) decoder utilizes the maximum a posteriori (MAP) algorithm. The proposed system's performance is evaluated in the presence of additive white Gaussian noise (AWGN) over SIMO Rayleigh fading channels. Simulation results are presented to demonstrate the bit-error rate (BER) performance as a function of the signal-to-noise ratio (SNR), demonstrating a close match to the SI-free case for the proposed system. Furthermore, we validate our results by deriving a tight upper bound on the performance of the proposed system using rate-1/2 convolutional codes together with quadrature phase-shift keying (QPSK) modulation, which asymptotically exhibits a close agreement with the simulated BER performance.