Low complexity MIMO receiver with decoupled detection

A low-complexity decoupled detection MIMO receiver structure is proposed for wireless systems with frequency-selective channels. This receiver structure is termed the decoupled Viterbi algorithm (DVA). In this structure, all the transmitted data streams are completely decoupled at the receiver and are detected independently. This structure can also be viewed as a variation of a MIMO minimum mean square error decision feedback sequence estimator (MMSE-DFSE) structure. Moreover, a certain MMSE optimization constraint, namely L-tap forward interference control (L-tap FIC), is needed to achieve complete decoupling of the transmitted data streams at the receiver. It is shown that the complexity of the DVA is "linear", meaning it increases only linearly with the number of transmitted data streams. Compared with other receivers that have "linear" complexity, such as partitioned Viterbi algorithm (PVA) (Miller, C. et al., IEEE Trans. on Commun., vol.49, no.11, 2001), DVA provides an attractive alternative since it does not require interchange of tentative decisions between different detection branches.