4-ary network coding for two nodes in cooperative wireless networks: exact outage probability and coverage expansion

Abstract

The fact that sensor nodes are powered by limited-capacity batteries makes power efficiency; one of the most critical issues in wireless sensor networks (WSNs). Advanced communication techniques combined with network coding and cooperative schemes have attracted considerable attention as ways to improve power efficiency in wireless transmission as well as to achieve high throughput and spectral efficiency in WSNs. In this study, we consider cooperative wireless networks with two nodes and one base station, and investigate the effect of using non-binary network coding on the enhancement in power efficiency. First, we derive the exact and general outage probability in our network coding scheme. We show that full diversity order can be obtained using a non-binary network code with GF(4) in the considered network. We use this result to study the extent to which the coverage area of a wireless source node can be expanded by network coding without increasing transmit power. Our results indicate that the benefit in terms of coverage expansion is substantial. The results included in this study show the influence of optimal power allocation on power efficiency. The optimum ratio of power allocation varies according to the wireless channel environments and the field size of network codes.

Exact outage probability of two nodes for cooperative networks using GF(4)

“…(16) Next, the exact outage probability with NBNC-4 for N1 is obtained by adding the results so far, i.e., (8), (12), (14), and (16), as follows:…”

“…Using nonbinary network coding (NBNC) with GF(q) for q > 2, it was shown that a full diversity order can be achieved [10] and [11]. In addition, for aspects of power efficiency techniques, a couple of benefits of the use of NBNC has been found in [12] as expansion of deployment of source nodes without increasing transmit power.…”

“…There are many studies about the analysis of outage probability in cooperative networks in [1], [7]- [12]. In [8], Chen et al showed that binary network coding (BNC), based on the arithmetic of size 2 of a Galois Field, viz.…”

Outage performance of a network coding aided multi‐user cooperative secondary network

“…Thus, as in the case of conventional cooperation, the application of network coding techniques in the cognitive radio context is expected to be beneficial. Indeed, the authors in evaluate the outage probability for a two users network with the use of a GF(4) non‐binary network code. The results show that the proposed scheme achieves full diversity order, and the coverage area can be expanded by the use of network coding without increasing the transmit power.…”

Evaluation framework for reconstruction of messages in cooperative coding schemes of multiple-sources and multiple-relays

“…Many efforts have since been devoted to clarifying if the network coding provides advantages over existing cooperative network schemes [3]- [11]. Chen et al [3] have shown that, assuming perfect inter-user channels, binary network coding based on the arithmetic of the Galois field of size 2, i.e., GF (2), can provide improved diversity gain and bandwidth efficiency in wireless networks when each user employs a simple decode-and-forward scheme.…”