Balanced Space-Time Block Coding Research Articles

Extended Balanced Space-Time Block Coding: Full Rate Full Diversity Wireless Multicasting

Multicasting is a spectrally efficient method of supporting group communication by allowing transmission of packets to multiple destinations using fewer resources. To incorporate Multi-Input Multi-Output diversity, Extended Balanced Space-Time Block Codes (EBSTBCs) have been proposed providing full diversity when one or more feedback bits are sent back via feedback channel. However, the EBSTBCs are designed for unicast communication in the literature. This paper presents a novel wireless multicasting scheme which selects the optimum EBSTBC for all mobile users to support wireless multicast. Extensive, detailed simulations are performed to show the feasibility of full rate and full diversity multicast service provisioning in Rayleigh fading channels.

Extended balanced space-time block coding for wireless communications

Diversity techniques are very effective tools to increase signal reception quality in Rayleigh fading channels. A well-known method to increase diversity in multi-input multi-output (MIMO) communication is transmit antenna selection (TAS). However, TAS is very sensitive to feedback errors. One of the alternative techniques to TAS is balanced space-time block coding (BSTBC) which guarantees full diversity for any number of transmit antennas, provided that few bits of feedback from the destination to the source are available. The main drawback of the BSTBC is limited coding gain since few numbers of code matrices can be generated in the originally proposed scheme. In this work, the authors extend the balanced space-time block code family to improve its coding performance. In our proposed scheme, larger number of codes can be generated for improved coding gain. The performance of the proposed scheme is investigated for both multi-input single-output (MISO) and cooperative communication cases. Relay selection (RS) algorithm - the TAS equivalent in the cooperative communications - is also considered. Simulation results show that near optimal (infinite feedback) performance can be achieved with four bit extension of the BSTBC and better signal-to-noise ratio can be obtained compared to TAS or RS schemes. The difference in performance becomes more prevalent in the presence of feedback errors.

Balanced space-time block coding: an efficient way to increase diversity with feedback

We propose full rate balanced space-time block codes which achieve full diversity for arbitrary number of transmit antennas, provided that one or a few feedback bits are sent to the transmitter denoting the relative state information of the channels. Moreover, all transmitted symbols can be decoded separately at the receiver, as in the case of orthogonal space-time block coding; thus the decoding complexity is linear. It is shown by computer simulations that the new approach provides signal-to-noise ratio improvement, and it is more resilient to feedback errors, compared to the transmit antenna selection technique, on the basis of same number of feedback bits.