Full-rate full-diversity differential MIMO

Abstract

Differential Multiple Input Multiple Output (MIMO) enables communication without the need for channel estimation and the associated overhead due to the transmission of pilots. A number of differential MIMO techniques were proposed using unitary or orthogonal space-time codes. These codes provide full diversity but achieve a data rate of no more than one symbol per channel use. This paper presents a block differential MIMO technique which can use any non-orthogonal full-rate full-diversity space-time code. This approach has a decoding complexity comparable to that of coherent MIMO.

On High Performance MIMO Communications with Imperfect Channel Knowledge

“…This corresponds to a block differential MIMO scenario as discussed in Section III-B. The BER performance of the block differential MIMO detector in [33] is shown for reference. Again, the performance of the GLRD approaches that of the optimal ML detector as increases.…”

“…Performance of the GLRD with = 5, 10 and = 1. Performance of the block differential MIMO detector [33] is shown for reference.…”

“…where , ,¯, , and¯are as defined in (33). Received data are obtained by multiplying the transmitted block with the channel matrix H and adding measurement noise.…”

“…With non-orthogonal high rate space-time codewords, block differential MIMO can be used instead [33]. The block differential system model is also given by (21).…”

“…X[0] is the pivotal matrix of the block differential encoding and is chosen as an appropriately scaled unitary matrix, commonly the identity matrix [33]. Considering a block of received data matrices for which the channel is assumed constant, we have…”