Multiple Access Relay Network :: Technology, Network

We consider a multiple access pass on earnings where eachsource transmit distribution channel coded packets, relay decode the transmittedpacket, gene rove network coded parity symbol, and retransmitit. We assume the relay has multiple antennas, sorelay to destination yoke is MIMO channel. We consider twoMIMO infection sensory system at the relay, spatial multiplexing(SM) and beamforming as transmit diversity (TD), and assumethat the relay usage different network coding scheme dependingon the MIMO transmission mode. In other words, we considera network with three types of linear combination channelcoding at the source, network coding at the relay, and mixingover the air with MIMO channel. The main objective of thepaper is to propose a transmission mode selection schemeat the relay which optimize these three linear combinationsconcurrently.There are numerous work that optimize either the networkcoding, MIMO transmission mode, or data rate over multipleaccess relay channel. Netwo rk coding techniques for singleantenna relay network has been addressed in 1 - 4. Authorsin 1 investigated the cooperative diversity gain offered by thenetwork coding. Authors in 2 proposed a network codingscheme based on low-density parity-check (LDPC) codes thataccounts for the lossy nature of wireless networks and showedthat a significant coding/diversity gain can be achieved. Authorin 3 investigated the tradeoff between reliability and rateas a function of node density and SNR, and showed howthe energy and node density can be traded in achieving agiven reliability-rate pair in single antenna case. Authors in4 examine an network coded cooperation which adaptivelymatch networks-on-graphs to the well-known class of codeson-graphs such as LDPC codes. This approach enables realtimeadaptation of network codes to variant link states andchanging network topologies. Network coding for multiple antennashave been studied for special network geometry in 5,6. Authors in 5 proposed a cross-l ayer design employingmultiple antenna techniques and network coding called MIMOtwo-way relay for one dimensional mesh network and authorsin 6 investigated the performance of MIMO network codingin bi-directional relay network. adaptational relay protocol hasbeen proposed for a network with single antenna relays in 7- 9 and for a network with multiple antennas using amplifyand forward protocol in 10, 11. Authors in 11 proposedan adaptive antenna selection scheme at both the relay and thesource for half-duplex MIMO amplify and forward relay protocol.Rate optimization for relay network has been addressedin 12, 13. Authors in 12 proposed throughput optimalcontrol policy for a parallel relay network with decode andforward protocol. Authors in 13 analyzed the performanceof variable-rate two phase collaborative diversity protocols andoptimized the transmission rate based on the node location.