Outage Performance of Dual Hop Full-Duplex MIMO Relay Networks with TAS/MRC over Rayleigh Fading Channels

13th International Symposium on Wireless Communication Systems (ISWCS) -- SEP 20-23, 2016 -- Poznan, POLANDWOS: 000386654000019In this paper, we investigate end-to-end (e2e) outage probability (OP) performance of dual hop full-duplex (FD) amplify-and-forward (AF) relay network with transmit antenna selection (TAS) and maximal-ratio combining (MRC) over independent identically distributed Rayleigh fading channels. In the network, source and destination are equipped with multiple antennas, and communicate with each other via a single relay, which is equipped with one receive and one transmit antennas. We assume that the direct link between the source and destination is not available. For signal transmission, TAS is used at the source by neglecting residual self-interference (RSI) effect and maximal-ratio combining (MRC) technique is employed at the destination for combining received signals. In order to simplify the theoretical derivations, we also investigate the e2e OP in case that the RSI is non-fading. OP expression is derived in integral form for the Rayleigh faded RSI effect. Moreover, in case of non-fading RSI effect, OP expression is derived in closed form. The analytical results are verified by the Monte Carlo simulations

Outage Probability Analysis of Full-Duplex Amplify-and-Forward MIMO Relay Systems

abstract: Multiple-input multiple-output systems have gained focus in the last decade due to the benefits they provide in enhancing the quality of communications. On the other hand, full-duplex communication has attracted remarkable attention due to its ability to improve the spectral efficiency compared to the existing half-duplex systems. Using full-duplex communications on MIMO co-operative networks can provide us solutions that can completely outperform existing systems with simultaneous transmission and reception at high data rates. This thesis considers a full-duplex MIMO relay which amplifies and forwards the received signals, between a source and a destination that do not a have line of sight. Full-duplex mode raises the problem of self-interference. Though all the links in the system undergo frequency flat fading, the end-to-end effective channel is frequency selective. This is due to the imperfect cancellation of the self-interference at the relay and this residual self-interference acts as intersymbol interference at the destination which is treated by equalization. This also leads to complications in form of recursive equations to determine the input-output relationship of the system. This also leads to complications in the form of recursive equations to determine the input-output relationship of the system. To overcome this, a signal flow graph approach using Mason's gain formula is proposed, where the effective channel is analyzed with keen notice to every loop and path the signal traverses. This gives a clear understanding and awareness about the orders of the polynomials involved in the transfer function, from which desired conclusions can be drawn. But the complexity of Mason's gain formula increases with the number of antennas at relay which can be overcome by the proposed linear algebraic method. Input-output relationship derived using simple concepts of linear algebra can be generalized to any number of antennas and the computation complexity is comparatively very low. For a full-duplex amplify-and-forward MIMO relay system, assuming equalization at the destination, new mechanisms have been implemented at the relay that can compensate the effect of residual self-interference namely equal-gain transmission and antenna selection. Though equal-gain transmission does not perform better than the maximal ratio transmission, a trade-off can be made between performance and implementation complexity. Using the proposed antenna selection strategy, one pair of transmit-receive antennas at the relay is selected based on four selection criteria discussed. Outage probability analysis is performed for all the strategies presented and detailed comparison has been established. Considering minimum mean-squared error decision feedback equalizer at the destination, a bound on the outage probability has been obtained for the antenna selection case and is used for comparisons. A cross-over point is observed while comparing the outage probabilities of equal-gain transmission and antenna selection techniques, as the signal-to-noise ratio increases and from that point antenna selection outperforms equal-gain transmission and this is explained by the fact of reduced residual self-interference in antenna selection method.Dissertation/ThesisMasters Thesis Electrical Engineering 201