1. A method, comprising: detecting a received signal for one of a structured irregular low-density parity-check (LDPC) code multiple-input-multiple-output (MIMO) orthogonal frequency division multiplex (OFDM) system and an iterative LDPC-coded MIMO-OFDM system; and iteratively determining an extrinsic output for the received signal at a channel decoder based on a current a posteriori probability (APP), such that each iteration comprises: determining the current APP at a soft data detector based at least in part on a prior extrinsic output from the channel decoder and a soft channel estimate from an iterative Recursive Least Squares-based channel estimator, the prior extrinsic output and the soft channel estimate each determined based on a prior APP.