Implementing Space-Time Coding On Software Defined Radio Platform

Space-time coding is a hot-topic of wireless communication in recent years.Space-time coding transmitters and receivers use multiple antennas to constitute aMIMO system. Compared with traditional channel coding, space-time block codingexploit a MIMO system by using its parallel flow to obtain diversity gain or improvethe sending rate, this technology makes a more efficient usage of the limitedspectrum.In this paper, we implement two kinds of typical space-time coding: Alamouticode and Space Division Multiplex on software defined radio platform:GNURadio/USRP and combined space-time coding with OFDM. We implementedencoding and decoding module and designed synchronization algorithm and channelestimation algorithm for MIMO system.The measurement has been made both in the attenuator channel (which simulatesan additive white gaussian noise channel) and the real channel, we measure thedeviation of the tx-signal and rx-signal in SISO-OFDM, Alamouti-OFDM andSDM-OFDM system, we use cumulative distribution to compare the deviation in eachsystem. The results show that in the real channel, diversity gain can be obtained byusing Alamouti coding which will make the communication more resistant tointerference. With Space Division Multiplex, the communication’s anti-jam capabilitywon’t decrease significantly, but the transmission rate can be multiplied.