Based On The Extended Orthogonal Matrix Empty Code Structure And Performance Analysis

Unlike the Gaussian channel, the wireless channel suffers from attenuation due todestructive addition of muiltipaths in the propagation media and due to interferencefrom other users. Being a good solution of such negative affection, MIMO system hasbeing attracted more and more attention, then it becomes to be key problem that howto arrange the signal input, decide which symbol should be transmitted at exact timewith which antenna. Space-time code was created to resolve this, according elaboratedesign, we can provide some replication of transmitted signal, we call diversity,which is less-attenuated and can be detected, thought that, the performance of thesystem is largely improved.This paper present a new class of space-time codes called spread orthogonalmatrix space-time trellis codes. We divide the codes of space-time block code intosub-aggregate by maximizing code gain distance reference to Ungerboeck rule. Inorder to achieve the max transmit rate, we also use the redundant matrix which neverused in space-time block code to avoid decreasing of diversity. By doing so, we find asystematic way to provide full diversity and improved coding gain over anteriorspace–time trellis code constructions. We also study the optimality of our setpartitioning and provide coding gain analysis. Codes operating at different rates, up tothe highest theoretically possible rate, for different number of states can be designedby using our optimal set partitioning.Simulation results show more than 2dB improvements over the codes presentedin the literature [1] while providing a systematic design methodology. In the mean time,we can construct many different encode scheme base on the states of encoder andtransmit rate systematically.Just like the traditional trills code, the new scheme is a tradeoff of code gain withthe number of encoder states and transmit rate, we give a elaborate analysis of codegain and simulation result to prove that a good code is the balance of diversity,transmit rate, number of encoder states ,decoder complexity and code gain.