Cooperative Communications Using Scalable, Medium Block-length LDPC Codes

Karkooti, Marjan; Cavallaro, Joseph R.

doi:10.1109/wcnc.2008.21

Cited by 12 publications

(37 citation statements)

References 13 publications

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“…However, we focus on code design with realistic assumptions, such as imperfect decoding of the codeword in the relay terminal, like in [9] and variant SNR within a single codeword, like in [3].…”

Section: Figure 1 Layout Of the Nodes In A Relay Networkmentioning

confidence: 99%

“…In [9], quasi-cyclic LDPC (QC-LDPC) codes are used in relay networks through repetition coding schemes. In the code design, the SNR is considered invariant within a single codeword.…”

Section: Figure 1 Layout Of the Nodes In A Relay Networkmentioning

confidence: 99%

“…The fact that [9] uses QC-LDPC codes makes them easier to implement and thereby more realistic, but on the other hand, they also get worse performance. Using the same time slots, transmission power, and processing of the codewords in the relay terminal with the decode and forward strategy as in [9], the codes proposed here achieve up to 1.9-dB gain over the QC-LDPC codes depending on the location of the relay with respect to the source and the destination. The better performance is partly due to the rate-compatible coding scheme and partly due to the UEP properties of the code.…”

Section: Figure 1 Layout Of the Nodes In A Relay Networkmentioning

confidence: 99%

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Jointly optimized rate-compatible UEP-LDPC codes for half-duplex co-operative relay networks

Khattak

Sandberg

2014

J Wireless Com Network

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This paper addresses the design of low-density parity-check (LDPC) codes for half-duplex co-operative relay networks. Structured rate-compatible codes with unequal error protection (UEP) are designed through joint optimization of the codes for the channels between source and relay and source and destination. The proposed codes clearly outperform simpler LDPC codes which are not optimized for relay channels and puncturing-based rate-compatible LDPC codes, and they show a significant performance improvement over the direct link communication depending on the position of relay. The optimization algorithm for the proposed codes is based on density evolution using the Gaussian approximation and optimal variable node degree distributions are found through iterative linear programming. Interestingly, they anyhow show performance which is almost comparable to the performance of codes optimized through a more complex non-linear optimization algorithm. We analyze the performance of our proposed codes with short, medium and long block lengths, and with low and high rates under realistic assumptions, i.e., imperfect decoding of the codeword at relay and variant signal-to-noise ratio within a single codeword.

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Section: Figure 1 Layout Of the Nodes In A Relay Networkmentioning

confidence: 99%

“…In [9], quasi-cyclic LDPC (QC-LDPC) codes are used in relay networks through repetition coding schemes. In the code design, the SNR is considered invariant within a single codeword.…”

Section: Figure 1 Layout Of the Nodes In A Relay Networkmentioning

confidence: 99%

Section: Figure 1 Layout Of the Nodes In A Relay Networkmentioning

confidence: 99%

See 1 more Smart Citation

Jointly optimized rate-compatible UEP-LDPC codes for half-duplex co-operative relay networks

Khattak

Sandberg

2014

J Wireless Com Network

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“…However, to achieve the expected gains, the antennas must be properly spaced, which may be impractical in small-sized devices. Cooperative communication [3][4][5][6][7][8][9][10] emerged as an alternative to the use of multiple antennas. Probably, the two most known cooperative protocols are the amplify-and-forward (AF) and the decode-and-forward (DF) [3].…”

Section: Introductionmentioning

confidence: 99%

“…Later, the association of error correcting codes with AF and DF protocols showed to considerably increase the performance [6][7][8][9][10][11], giving rise to what is called coded cooperation. Convolutional codes [6,8], turbo codes [7,8] and LDPC codes [9][10][11] are some important coding techniques that were associated with the relay channel.…”

Section: Introductionmentioning

confidence: 99%

Cooperative partial retransmission scheme in incremental decode-and-forward relaying

Brante

Souza

Pellenz

2011

J Wireless Com Network

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In this paper, we present a novel hybrid automatic repeat request (HARQ) scheme for cooperative communication systems, called cooperative partial retransmission (CPR). The method is based on the retransmission of only a fraction of the original code word by the cooperating nodes. Based on the outage analysis, we derive the theoretical throughput expressions that are compared to numerical simulations using LDPC codes, showing that CPR outperforms regular cooperative HARQ techniques. Additionally, we show that the CPR throughput, even using a single relay, may be considerably larger than the throughput of a regular cooperative HARQ scheme using multiple relays. Finally, the energy consumption analysis of the schemes shows that CPR consumes less energy than regular cooperative HARQ, mainly due to the shorter retransmissions.

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Distributed Decoding in Cooperative Communications

Karkooti

Cavallaro

2007

2007 Conference Record of the Forty-First Asilomar Conference on Signals, Systems and Computers

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Abstract-In this paper, we present a novel relaying strategy called distributed and partial decoding. This strategy can be viewed as a variation of the decode and forward with the difference that the relay partially decodes the signal, re-transmits it to the destination, and the destination continues the decoding. By distributing the decoding process between the relay and the destination, the relay uses less processing power and less time. This is very suitable for practical applications in which relays are battery-operated (such as handsets) and do not want to use all their battery power on relaying the data of other users.

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Cooperative Communications Using Scalable, Medium Block-length LDPC Codes

Cited by 12 publications

References 13 publications

Jointly optimized rate-compatible UEP-LDPC codes for half-duplex co-operative relay networks

Jointly optimized rate-compatible UEP-LDPC codes for half-duplex co-operative relay networks

Cooperative partial retransmission scheme in incremental decode-and-forward relaying

Distributed Decoding in Cooperative Communications

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