Realization of TDD Two-way Multi-hop Relay Network with MIMO Network Coding

Abstract

This paper develops the first prototype hardware for TDD two-way multi-hop relay network with MIMO network coding. Since conventional wireless multi-hop relay networks have a drawback of low data rate, TDD two-way multi-hop relay networks have been studied as a solution to realize high data rate recently. In the networks, forward and backward streams are spatially multiplexed by using interference cancellation techniques such as MIMO beamforming or MIMO network coding. In this paper, demonstration system for TDD two-way multihop relay network with MIMO network coding (called 2-way relay network hereafter) is developed by using the prototype hardwares. In the demonstration system, each transmitter and receiver performs network coded broadcast and MIMO multiple access respectively. By using the demonstration system, network throughput is measured in a real indoor environment to prove the realization and effectiveness of the 2-way relay network. The network throughput of the 2-way relay network is about twice as large as that of the simple TDD one-way multi-hop relay network (1-way relay network), and higher than that of the direct link at all average end-to-end SNRs. From the result, the realization and effectiveness of the 2-way relay network is proved in the real indoor environment.

Implementation of a two‐way relay network with compute‐and‐forward in GNU Radio

“…Recently, a number of works have reported successful implementation of DNC testbeds that yielded significant increase of network throughput compared with traditional approaches . In contrast, limited results are available on the implementation of PNC, despite the fact that the theory of PNC has been quickly developing in the last decade.…”

Software defined radio implementation of a two-way relay network with digital network coding

“…Only a few implementations of DNC in TWRN or larger relay networks are reported in [2], [5] and [6]. For example, [5] demonstrates essential reduction of time required to exchange video files between smartphones, in case DNC is employed.…”

“…In addition to demonstrating advantages of DNC, the authors also investigate the implementation issues of a large network, such as the congestions control, traffic patterns and optimal routing. Another example of implementation of a multi-hop relay network with MIMO network coding is provided in [6]. The MIMO TWRN implements data exchange within two time slots by transmitting messages from both the terminals at the same time.…”