Combined array processing and space-time coding

Performance of Layered Steered Space–Time Codes in Wireless Systems

“…This scheme can be generalized to two transmit antennas and M receive antennas to provide a diversity order of 2M. Similar work was considered in [5] where space-time trellis codes (STTC) were used as the component codes.…”

“…One advantage of using MLSTBC over MLSTTC is that the orthogonal structure and the short code length can be exploited at the receiver to reduce the minimum required number of receive antennas [50]. For MLSTTC [5,51], the number of receive antennas should be at least equal to the total number of transmit antennas, while for MLSTBC, it should be at least equal to the number of layers [51].…”

“…In [5], Tarokh et al proposed using a combined scheme that is called multi- is used in each layer of VBLAST with different transmission power. In other words, the decoding order is pre-determined based on the power level.…”

Space-Time<tex>$D$</tex>-Block Codes via the Virtual MIMO Channel Representation

“…First, suppose is of full rank. The Gaussian probability density function of is (13) Therefore, the expectation in (12) can be computed as (14) Since is positive definite and is nonnegative definite, the sum is positive definite. In particular, it is invertible.…”

“…A related important benefit of the virtual representation is that it naturally facilitates diversity-versus-rate tradeoff, which overcomes the rate deficiency associated with space-time block codes (and space-time -block codes as well) [11]- [13] relative to high rate schemes such as spatial multiplexing (see, e.g., [1]). Applying the principle of combining array processing and space-time coding in [14], we propose a "divide-and-conquer" approach in Section V to decompose the original channel into several lower dimensional subchannels which can support multiple independent data streams simultaneously. However, interference among different subchannels in general may create a bottleneck in system performance.…”