Blind iterative channel estimation and detection for LDPC-coded cooperation under multi-user interference

This paper proposes an iterative algorithm for blind estimation of channel coefficients and interference-plus-noise power spectral density in a coded cooperative system using rate-compatible low-density parity-check codes. The expectation-maximization (EM)-based estimation algorithm is applied to an interference-limited network with multiple source-relay pairs. After the initial blind estimation, the soft decoder output is used to re-compute the channel coefficient and noise-PSD values. The cooperative system with blind EM estimation is found to have a decoding performance comparable to that obtained with time-multiplexed and superimposed pilot-assisted channel estimation (PACE) methods. At the same time, the proposed scheme is shown to have a higher throughput than the PACE methods considered for comparison.