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International Journal of Sensors, Wireless Communications and Control

Editor-in-Chief

ISSN (Print): 2210-3279
ISSN (Online): 2210-3287

Research Article

Asymmetric Successive Compute-and-Forward and the Capacity Gap for the Gaussian Two-way Relay Channel

Author(s): Leila Ghabeli*

Volume 13, Issue 3, 2023

Published on: 21 July, 2023

Page: [179 - 191] Pages: 13

DOI: 10.2174/2210327913666230605120441

Price: $65

Abstract

Background: The compute-and-forward strategy is one of the outstanding methods which is used for interference management in wireless relay networks where decoding linear combinations of code words is required. Recently, many efforts have been made for decoding integer and noninteger combinations. The difference between the methods is the manner of handling different conditions of networks, such as equal or unequal power constraints and equal or unequal channel gains.

Objectives: In this work, we present a modified n-step asymmetric successive compute-and-forward strategy for the communication network where we have both unequal power constraints and unequal channel gains conditions.

Methods: In the proposed method, we scale channel gains and coefficients with the square root of power constraints. In this way, despite previous methods, without the need for scaling factors in our formulation, it is still able to solve the problem of general Gaussian relay networks with unequal power constraints and unequal channel gains. We also use scaling factors in our method in order to have the ability to divide the rates between users fairly.

Results and Conclusion: We evaluate the ability of the modified strategy for the uplink communication of the two-way relay channel, where one relay can help communication between the two users. At the relay, we decode the linear combinations of the messages of the two users and obtain 1/2 bit/sec/Hz per user capacity gap from the cut-set bound. Through some theoretical and simulation results, we show that by appropriately adjusting parameters, different points and areas of rate regions are achievable.

Graphical Abstract

[1]
Nazer B, Gastpar M. Compute-and-forward: Harnessing interference through structured codes. IEEE Trans Inf Theory 2011; 57(10): 6463-86.
[http://dx.doi.org/10.1109/TIT.2011.2165816]
[2]
Nazer B. Successive Compute-and-Forward Proc International Zurich Seminar on Communication. Zurich, Switzerland. 2012; pp. 103-6.
[3]
Nam W, Chung SY, Lee YH. Nested lattice codes for Gaussian relay networks with interference. IEEE Trans Inf Theory 2011; 57(12): 7733-45.
[http://dx.doi.org/10.1109/TIT.2011.2170102]
[4]
Ntranos V, Cadambe VR, Nazer B, Caire G. Asymmetric Compute-and-Forward Proc of Asilomar Conference on Signals, Systemsand Computers. 2013; 1174-81.
[5]
Zhu J, Gastpar M. Asymmetric compute-and-forward with CSIT Proc International Zurich Seminar on Communications. Zurich, Switzerland.. 2014; p. arXiv:1401.3189 [cs.IT].
[6]
Zhu J, Gastpar M. Gaussian Multiple access via compute-and-forward. IEEE Trans Inf Theory 2017; 63(5): 2678-95.
[http://dx.doi.org/10.1109/TIT.2016.2605121]
[7]
Lim SH, Feng C, Pastore A, Nazer B, Gastpar M. A joint typicality approach to compute-forward. IEEE Trans Inf Theory 2018; 64(12): 7657-85.
[http://dx.doi.org/10.1109/TIT.2018.2872053]
[8]
Ghabeli L, Derpich MS. “Successive compute-and-forward,” Iran workshop on communications and Information theory. IWCIT, Tehran, Iran 2016; pp. 1-6.
[http://dx.doi.org/10.1109/IWCIT.2016.7491625]
[9]
Rankov B, Wittneben A. Spectral efficient signaling for halfduplex relay channels Proc of Asilomar Conference on Signals, Systems and Computers. 2005; 1066-71.
[10]
Shannon CE. Two-way communication channels Proc 4th Berkeley Symp Math Stat Prob. 1961; 611-44.
[11]
Gunduz D, Tuncel E, Nayak J. Rate regions for the separated twoway relay channel Proc 46th Annual Allerton Conference Sept 23-26,. 2008; 2008: pp. 1333-40.
[http://dx.doi.org/10.1109/ALLERTON.2008.4797715]
[12]
Nam W, Chung SY, Lee YH. Capacity of the gaussian twoway relay channel to within 1/2 bit. IEEE Trans Inf Theory 2010; 56(11): 5488-94.
[http://dx.doi.org/10.1109/TIT.2010.2069150]
[13]
Ghabeli L, Derpich MS. Approaching the capacity of two‐pair bidirectional Gaussian relay networks. IET Commun 2015; 9(12): 1458-65.
[http://dx.doi.org/10.1049/iet-com.2014.0710]
[14]
Ghabeli L, Derpich MS. Approaching the capacity of Two-way Gaussian relay channel with relay private messages IEEE Int Symp on Info. Theory, Hawaii, USA. 2014; pp. 2729-33.
[http://dx.doi.org/10.1109/ISIT.2014.6875330]

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