Cooperative quadrature physical layer network coding in wireless relay networks

Abstract

SUMMARYThis paper proposes a cooperative quadrature physical layer network coding (CQPNC) scheme for a dual-hop cooperative relay network, which consists of two source nodes, one relay node and one destination node. All nodes in the network have one antenna, and the two source nodes transmit their signals modulated with quadrature carriers. In this paper, a cooperative quadrature physical layer network coded decode-andforward (DF) relay protocol (CQPNC-DF) is proposed to transmit the composite information from the two source nodes via the relay node to the destination node simultaneously to reduce the number of time slots required for a transmission. The proposed CQPNC-DF relay protocol is compared with time-division multiple-access amplify-and-forward (TDMA-AF), TDMA-DF, cooperative network coded DF (CNC-DF) and cooperative analog network coded AF (CANC-AF) relay protocols to demonstrate its effectiveness in terms of bit error rate (BER) and system throughput under different propagation conditions. The simulation results reveal that the proposed CQPNC-DF relay protocol can significantly improve the network performance. Compared with two TDMA schemes and CNC-DF, the proposal can provide up to 100% and 50% throughput gains, respectively. Moreover, no matter what the scene, the proposed scheme always has the lowest BER in the low SNR region.

On scalability of physical layer network coding with modulo‐sum mapping overN‐way relay channels

“…1,11,21 After TWRC, utilizing PLNC in large cooperative networks with the temptation to achieve maximum data rate has been always of interest. 22 Recently, He and Liew 13 have done a good effort in this field and show a general network can be decomposed into smaller subnetworks based on PLNC called PLNC atoms. Nine models for these subnetworks including 2 or more users is then proposed in He and Liew, 13 and it is shown decomposing method in such a networks can significantly improve the throughput performance.…”

“…For N =2, this structure is called TWRC, and if it works based on PLNC technology, it will require 2 time slots for information exchange providing 100% improvement in throughput as compared with traditional relay networks without network coding . After TWRC, utilizing PLNC in large cooperative networks with the temptation to achieve maximum data rate has been always of interest . Recently, He and Liew have done a good effort in this field and show a general network can be decomposed into smaller subnetworks based on PLNC called PLNC atoms.…”

Energy efficiency based on joint mobile node grouping and data packet fragmentation in short‐range communication system

“…Intra‐cloud nodes should cooperate with each other for recovering the lost data. If there are no delay constraints, cooperative communication based on network coding can be used for efficient error recovery, especially on random network coding . If errors cannot be recovered by means of intra‐cloud cooperative communication, inter‐cloud cooperation can be further considered.…”

BER‐modified regenerative protocols for OFDM‐based two‐way wireless relay channel

“…Besides traditional exclusive-or coding method, the authors in [10] and [11] also proposed orthogonal physical network coding strategies to enable relay to decode messages from A and B in two-stage relaying (with the expense of doubling the degree of freedom). In addition, the authors in [12] examined the relay selection problem in multi-relay two-way analog network coding networks and the idea of network coding was also extended to dual-hop relay networks by the authors in [13] recently.However, for symbol-level relaying, both three-stage network coding and two-stage physical network coding suffer the error propagation problem. It is resulted by the fact that when relay regenerates new signal, errors may be introduced; lacking of ways to see those errors, node A or B can only decode what they have received.…”

“…Besides traditional exclusive-or coding method, the authors in [10] and [11] also proposed orthogonal physical network coding strategies to enable relay to decode messages from A and B in two-stage relaying (with the expense of doubling the degree of freedom). In addition, the authors in [12] examined the relay selection problem in multi-relay two-way analog network coding networks and the idea of network coding was also extended to dual-hop relay networks by the authors in [13] recently.…”