1. A receiver operative in a multiple input, multiple output (MIMO) wireless communication network in which two or more streams of communication symbols are transmitted, comprising: a whitening joint detector comprising a pre-filter operative to suppress a first subset of the received MIMO streams as colored noise; and a primary joint detector operative to process a second subset of the MIMO streams and to output a preliminary solution obtained by minimizing a whitening joint detection metric; and a secondary detector operating in the vicinity of the primary joint detector preliminary solution, and operative to improve the preliminary solution by comparison to a full joint detection metric.