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

Kramarev, Dmitry; Sakzad, Amin; Viterbo, Emanuele

doi:10.1002/ett.2984

Cited by 5 publications

(11 citation statements)

References 24 publications

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“…There were several PNC implementations prior to our work [6], [7], [11], [12], [13], [14], [15], [16], [17], [18]. These implementations did not use channel precoding.…”

Section: Comparison With Prior Pnc Implementationsmentioning

confidence: 99%

“…These implementations used bandwidth of <5M Hz; higher bandwidth requires faster processing (which is a challenge to SDR development using universal software radio peripheral (USRP) and GNUradio) and tighter synchronization. The implementation in [15] used the RS code, and those in [6], [7], [11], [14], [17], [18] used convolutional codes. In comparison to these implementations, our work can support higher-order modulations (16-QAM and 9-QAM), higher bandwidth (20M Hz), and lattice codes, without the need for expensive oscillators or multiple antennas.…”

Section: Comparison With Prior Pnc Implementationsmentioning

confidence: 99%

“…The authors of [15] implemented a simplified lattice-coded PNC with QPSK modulation and Reed Solomon (RS) code. However, the QPSK-RS code is still a conventional block code, and differs from lattice codes in its construction and performance.…”

Section: Related Workmentioning

confidence: 99%

“…This system does not realize a lattice-coded PNC in its true spirit, and cannot approach the capacity of TWRN. Also, [15] did not implement channel precoding (i.e., the channels can be misaligned, resulting in performance loss), and just used GPSDO to ensure synchronization of the oscillators.…”

Section: Related Workmentioning

confidence: 99%

“…In particular, lattice codes have never been implemented in practical systems. Although some experimental PNC prototypes have been demonstrated to date [6], [7], [11], [12], [13], [14], [15], [16], [17], [18], these prototypes could only achieve low-order binary phase shift keying (BPSK) and quadrature phase shift keying (QPSK) modulations. None of them makes use of lattice coding to realize the full potential of PNC.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Mobile Lattice-Coded Physical-Layer Network Coding with Practical Channel Alignment

Tan

Liew

Huang

2018

IEEE Trans. on Mobile Comput.

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Physical-layer network coding (PNC) is a communications paradigm that exploits overlapped transmissions to boost the throughput of wireless relay networks. A high point of PNC research was a theoretical proof that PNC that makes use of nested lattice codes could approach the information-theoretic capacity of a two-way relay network (TWRN), where two end nodes communicate via a relay node. The capacity cannot be achieved by conventional methods of time-division or straightforward network coding. Many practical challenges, however, remain to be addressed before the full potential of lattice-coded PNC can be realized. Two major challenges are: (1) for good performance in lattice-coded PNC, channels of simultaneously transmitting nodes must be aligned; (2) for lattice-coded PNC to be practical, the complexity of lattice encoding at the transmitters and lattice decoding at the receiver must be reduced. We address these challenges and implement a first lattice-coded PNC system on a software-defined radio (SDR) platform. Specifically, we design and implement a low-overhead channel precoding system that accurately aligns the channels of distributed nodes. In our implementation, the nodes only use low-cost temperature-compensated oscillators (TCXO)-a consequent challenge is that the channel alignment must be done more frequently and more accurately compared with the use of expensive oscillators. The low overhead and accurate channel alignment are achieved by (1) a channel precoding system implemented over FPGA to realize fast feedback of channel state information; (2) a highly-accurate carrier frequency offset (CFO) estimation method; and (3) a partial-feedback channel estimation method that significantly reduces the amount of feedback information from the receiver to the transmitters for channel precoding at the transmitters. To reduce lattice encoding and decoding complexities, we adapt the low-density lattice code (LDLC) for use in PNC systems. Experiments show that our implemented lattice-coded PNC achieves better bit error rate performance compared with time-division and straightforward network coding systems. It also has good throughput performance in mobile non-LoS scenarios.

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“…There were several PNC implementations prior to our work [6], [7], [11], [12], [13], [14], [15], [16], [17], [18]. These implementations did not use channel precoding.…”

Section: Comparison With Prior Pnc Implementationsmentioning

confidence: 99%