  Orthogonal signal-division multiplexing (OSDM) is an attractive alternative
to conventional orthogonal frequency-division multiplexing (OFDM) due to its
enhanced ability in peak-to-average power ratio (PAPR) reduction. Combining
OSDM with multiple-input multiple-output (MIMO) signaling has the potential to
achieve high spectral and power efficiency. However, a direct channel
equalization in this case incurs a cubic complexity, which may be expensive for
practical use. To solve the problem, low-complexity per-vector and block
equalization algorithms of MIMO-OSDM are proposed in this paper for
time-invariant and time-varying channels, respectively. By exploiting the
channel matrix structures, these algorithms have only a linear complexity in
the transformed domain. Simulation results demonstrate their validity and the
related performance comparisons.
