Analysis of the Generalized DF-CF for Gaussian Relay Channels: Decode or Compress?

Decode-and-Forward (DF) and Compress-andForward (CF) are two efficient cooperation strategies for relay networks. Combination of DF and CF strategies is promising to improve the achievable rate of cooperative communication systems. To thoroughly aggregate the advantage of DF and CF strategies, we put forward a joint Power Allocation and Strategy Selection (PASS) scheme for half-duplex relay channel. The PASS scheme is shown to achieve a higher rate compared with regular hybrid DF/CF scheme. The rate gain obtained in the static relay channel results from actively adjusting and optimizing the relay power followed by selecting the better strategy between DF and CF. Particularly, when the relay receives and transmits in sequential time slots, we characterize the positive rate improvement area of PASS scheme analytically and give a near optimal setting for approaching the best rate performance. The PASS scheme is extended to fading relay channels. We show that the rate increment obtained from the PASS scheme is further magnified by employing an advanced relay power allocation technique over channel states. The corresponding optimal power allocation is established based on the concavity of the rate achieved by the PASS scheme in static relay channel. Numerical results are presented to validate the analysis.

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“…One can reformulate (35) as (24). As K * is the solution of (24), It is not hard to write T II as (23) following from the definition of K.…”

Section: Appendix D Proof Of Theorem 45mentioning

confidence: 99%

“…In static channel gain case, CF was superposed on DF in [7], leading to a positive rate gain [23]. This superposition scheme was thoroughly investigated in [24] and [25].…”

Section: Introductionmentioning

confidence: 99%

Joint Power Allocation and Strategy Selection for Half-Duplex Relay System

Chen

Fan

2017

IEEE Trans. Veh. Technol.

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“…The rate achieved by DF and CF strategies for full-duplex relay channel was presented in [1]. With more complicated coding structures and decoding proce dures, it was found that combining DF and CF strategies can achieve a larger rate [1] [2][3] [4]. Due to the generality of DF and CF strategies, they have been adopted in complicated relay networks, achieving capacity asymptotically [5] [6].…”

Section: Introductionmentioning

confidence: 99%

“…Following the equal-time-phase assumption and fixed source power assumption, the rate functions are specified as [7] RD F( P2) � � max min {C(h�lPd + C( (Ip 2 )h�lPl) ' 2 o :S;p9 C( h�lPl) + C( h�lPl + 2h�2P2 + 2ph3lh32,/2PlP2)} (4) l; 1 2 RCF(P2) = "2 C( h 3l Pl)+ � C(h 2 P 2h�lPlh�2P2…”

mentioning

confidence: 99%

A hybrid DF and CF scheme with adaptive power allocation for half-duplex relay channel

Chen

Fan

2015

2015 IEEE International Conference on Communications (ICC)

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Ahstract-The relay scheme and the corresponding rate per formance are considered for a half-duplex relay channel in which the source can only transmit information with fixed power. As different relay strategies result in different rate performance, we first present a decision criterion for selecting between Decode and-Forward (DF) and Compress-and-Forward (CF) strategies by thoroughly analyzing their achievable rate. Based on the analysis result, the maximmn of the DF rate and CF rate can be achieved by strategy selection procedure. To further obtain a larger rate, we put forward a hybrid DF-CF scheme in which the strategy selection between DF and CF is combined with active relay power allocation efficiently. It is shown that the concave envelope of the maximum of DF rate and CF rate is achievable via our new developed hybrid scheme. For the convenience of implementation, we also present a suboptimal setting for the hybrid DF -CF scheme. Nmnerical results show that the suboptimal setting can achieve a rate approaching the maximal rate.

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“…show that, under Rayleigh fading channel conditions, this selection yields significant gains over fixed DF and CF. The work in this chapter was published, in part, in [12] and [13].…”

Section: Optimization-based Approachmentioning

confidence: 99%

Enhancing Rates In Relay Channels

Luo¹

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The main objective of this study is to investigate the structures and procedures which are promising to achieve higher rates and larger rate regions in the relay channels and the communication networks that contain relay nodes. In particular, the study places particular emphasis on the relaying techniques pertaining to compressand-forward.The thesis first examines a generalization of decode-and-forward (DF) and compress-and-forward (CF) in Gaussian channels. Although this generalization has been known for over thirty years, the result in this thesis is the first to illustrate the signal-to-noise ratio (SNR) regions in which the generalization reduces to constituent DF or CF schemes. In particular, the thesis demonstrates the existence of SNR regions in which the generalization is guaranteed to supersede both DF and CF, but with a gain of within 0.5 bits per channel use.Having gained insight into the random binning in the CF scheme, this thesis argues that a new decoding procedure exploiting the N-to-1 mapping based on binning is able to relax the rate constraint on the relay transmission, and generalize the noisy network coding based schemes which are constrained to the 1-to-1 mapping. This thesis identifies two instances in which exploiting the N-to-1 mapping inherent in this generalization yields rate gains, even though it does not yield such a gain in other multimessage networks.ii In the analysis of a secure communication problem, the thesis introduces the concept of "friendly" eavesdropper in a broadcast channel in the presence of a malicious Gaussian jammer. Taking advantage of the N-to-1 mapping, it is shown that the new decoding procedure enables CF to achieve the capacity of the channel.iii Dedicated to Kate Yang and Jeffrey Luo iv Acknowledgments

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Analysis of the Generalized DF-CF for Gaussian Relay Channels: Decode or Compress?

Cited by 9 publications

References 31 publications

Joint Power Allocation and Strategy Selection for Half-Duplex Relay System

Joint Power Allocation and Strategy Selection for Half-Duplex Relay System

A hybrid DF and CF scheme with adaptive power allocation for half-duplex relay channel

Enhancing Rates In Relay Channels

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