Diversity and spatial-multiplexing tradeoff under linear decoding

We investigate a MIMO spatial-multiplexing (SM) system with linear decoding at the receiver. The majority of existing MIMO transmission schemes, such as V-BLAST, focus primarily upon spatial multiplexing and can only offer diversity advantages if the number of receiver antennas exceeds the number of transmitters. We propose a rate-preserving linear coding and linear decoding algorithm that, through power weighting, allows for a tradeoff between spatial multiplexing and receiver diversity/array gain while preserving the data-rate under the same modulation. The optimal tradeoff between SM and receiver diversity/array gain for a given MIMO system is also investigated.