Paper Title
Performance Evaluation of Higher Order Alamouti Schemes with Different Modulation Formats

In wireless communication fading of channels is the serious cause of the received degraded signals. Orthogonal transmitter diversity such as time diversity and frequency diversity is quite simple to implement and, with optimum signal combining, can take full advantage of fading multipath channels. Receive diversity techniques like maximal ratio receive combining have been popular means of introducing multiple antennas into communication systems. Alamouti proposed a scheme, Space-time block codes which introduces transmit diversity with similar complexity and performance as maximal ratio receive combining. This paper evaluates the performance of Space-time Block Code (STBC), for multiple transmitters and multiple receiver antennas along with different modulation formats like circular, square and rectangular constellation. In this paper a systematic method of designing for arbitrary Multiple Input, Single Output (MISO) system and then extended to MIMO systems with multiple receiving antennas. Maximum likelihood detector was used in the receiver which shows significant reduction in BER for increased values of Eb/N0. Index terms - Diversity, Flat fading Rayleigh Channels, ML detector, STBC