When the Alamouti code is applied (as a space-time block code) to an OFDM system with transmit diversity, the simple Alamouti decoding requires that each subchannel is flatfading and constant over two symbol periods(Alamouti codeword period). The second requirement makes the Alamouti decoding scheme not suitable for time varying channels. In this paper, we propose a new decision directed receiv...

Alamouti code is a simple space-time code that can be used for transmit diversity systems. This is a class of easily decoded space-time codes that achieve full diversity order in Rayleigh fading channels. Alamouti code exist only for certain numbers of transmit antennas and do not provide array gain like diversity techniques that exploit transmit channel information. When Channel State Informat...

Transmit diversity schemes such as the Alamouti space-time code have been shown to be viable candidates to enable robust dual-antenna transmission from maneuvering air vehicles. However, due to the complicated structure of shaped offset quadrature phase shift keying (SOQPSK) modulation, the Alamouti approach has not been applicable to SOQPSK systems. This paper develops a precoding and detectio...

This paper carries out the integration of a space–time block code (STBC) technique into a chaos shift keying (CSK) system. To that end, an Alamouti space–time code scheme is combined with the CSK system for two transmit and two receiver antennas. Our proposed scheme is a simple configuration that combines the advantages of STBC and chaotic modulation. Because the chaotic signals have a low cros...

We construct a full data rate space–time (ST) block code over = 2 transmit antennas and = 2 symbol periods, and we prove that it achieves a transmit diversity of 2 over all constellations carved from [ ] . Further, we optimize the coding gain of the proposed code and then compare it to the Alamouti code. It is shown that the new code outperforms the Alamouti code at low and high signal-to-noise...

An iterative receiver is proposed for the downlink of CDMA communication systems that employ both a convolutional channel code and a space-time trellis code to achieve transmit diversity in the presence of channel fading. The proposed iterative receiver operates by exchanging extrinsic information between the channel and space-time decoders in each iteration. Comparison of performance results, ...