Joint power and location optimization for analog network coding with multi-antenna sources

Abstract

We consider a two-way relay system where multiantenna sources employ beamforming to communicate bidirectionally via a single-antenna relay with analog network coding over Nakagami-m fading channels. We address the problem of both separate and joint optimization of power allocation and relay location in order to minimize the overall system outage probability. Our results demonstrate that separate optimization of relay location is more significant than that of power allocation to improve the overall system outage performance. We further emphasize that the joint optimization of power allocation and relay location can provide noticeable outage performance improvement over unbalanced per-hop fading conditions and/or nonidentical antenna configurations.

Relay Deployment for AF-MIMO Two-Way Relaying Networks with Antenna Selection

“…So the CDF of ub m W in (11) can be derived as follows: As can be observed from (14), the outage probability is clearly a function of the distance between the sources and the relay. In the following, the best position of the relay to achieve globally minimum outage probability is analyzed by using the closed-form outage probability approximation in (14).…”

“…In [13], the analysis and tests in practical indoor Environments show that even a sub-optimal relay placement algorithm can improve the system performance. In [14], a joint power and location optimization solution for MIMO TWRN is proposed and shows that optimal relay location can bring more performance gain compared with optimal power allocation. In [15], relay location optimization problem is investigated to illustrate the effects on energy efficiency for two-way relaying.…”

Physical‐layer network coding with multi‐antenna transceivers in interference limited environments

“…[1][2][3], and the references therein). Furthermore, in [4], the problem of both separate and joint optimisation of power allocation and relay location to minimise the outage probability has been solved. Considering AF two-way relay systems with multiple antenna transceivers, the authors of [5] developed an algorithm to find the optimal beamforming matrix for the relay to optimise the worse end-to-end signal-to-noise ratio (SNR).…”

“…For the case that TWRNs employ multi-antenna transceivers, most of related works assume the ideal scenario, i.e. no interference imposed to the transceivers, when deriving analytical formulas for outage probability, SER, channel capacity, diversity order, or beamforming vectors [4,6,[12][13][14][15][16]. In these studies, the associated power allocation strategies are developed based on the restricted assumption that the transmit power of the relay as well as total transmit power of the two sources are each equal to half of total transmit power of the system.…”

“…The novelty of our work can be argued in three folds. First, as compared to [4,6], the more complicated, but practical scenario of beamforming AF TWRNs is considered in our study, i.e. the system suffers from multi-user co-channel interference.…”