Efficient decoding over power-line channels

Han

Mow

et al. 2013

IEEE Trans. Commun.

Self Cite

It has been known that communication systems are susceptible to strong impulsive noises. To combat this, convolutional coding has long served as a cost-effective tool in the context of moderately frequent occurrence of memoryless impulses with given statistics. Nevertheless, the impulsive noise statistics is hard to be accurately modeled and is generally not time-invariant, making the respective system design challenging. In this article, in the absence of full knowledge of the probability density function (PDF) of impulsive noises, we devise an efficient decoding scheme for single-carrier narrowband communication systems by incorporating a design parameter into the recently introduced joint erasure marking and This is the Pre-Published Version 2 Viterbi decoding algorithm, dubbed the metric erasure Viterbi algorithm (MEVA). The proposed scheme is equivalent to incorporating a well-designed clipping operation into the Viterbi algorithm, of which the clipping threshold has to be appropriately set. In contrast with existing publications that often resort to extensive simulations, we characterize the bit error probability performance associated with the clipping threshold by deriving its Chernoff bound. Simulation results reveal that with a judicious selection of the clipping threshold, the MEVA can be on par with its optimal maximum-likelihood decoding counterpart under fairly general circumstances.

Section: Metric Erasure Viterbi Algorithm (Meva)mentioning

confidence: 99%

Section: Metric Erasure Viterbi Algorithm (Meva)mentioning

confidence: 99%

Robust Decoding for Convolutionally Coded Systems Impaired by Memoryless Impulsive Noise

Han

Mow

et al. 2013

IEEE Trans. Commun.

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“…Instead of using a limiter, this work attempts to address the impulse noise by directly incorporating a clipping feature into the metric of turbo decoder. Recall that the MEVA, on the basis of a clipped-on trellis, exhibits a BEP performance on par with the maximum likelihood decoder in [20]. As the clipping threshold plays a crucial role on the BEP performance, this study presents a brief review of the MEVA before discussing the proposed decoder metric.…”

Section: Decoder Featured With Clipped-on Trellismentioning

confidence: 99%

Robust turbo decoding in impulse noise channels

2013 IEEE 17th International Symposium on Power Line Communications and Its Applications

Tsai

Han

2013

Powerline communications, an enabling technology for data networking alternative, susceptible to impulse noise such that it is likely to miss an assured quality of service. Turbo coding has long served as an essential tool to overcome this obstacle. However, this comes at the cost of estimating the statistics of impulse noise, which is generally not timeinvariant and may change rapidly over time, further increasing receiver complexity. This study proposes clipping on trellis to avoid this problem. A corresponding decoder metric dictated by the clipping threshold, which is a function of the probability of guessing for the unknown impulse arrival probability, was properly formulated to leverage the coding gain. Regardless of the impulse noise model assumed, the simulation results in this study, in terms of bit error probability, show that the proposed decoding scheme is robust to impulse and performs fairly close to its sophisticated counterpart, which however fully exploits the statistics of the impulse noise.

“…In analogy with the MEVA scheme [12], devised for singlecarrier transmission to deal with memoryless impulsive noise, the upper bound |γ f |, when conditioned on X mR = E s /2, satisſes the following equation,…”

Section: B Design Of Clipping Thresholdmentioning

confidence: 99%

“…in [12], induces a similar bit error rate (BER) performance to the maximum-likelihood decoding method for single-carrier transmission system, given the arrival probability of impulses. Inspired by that feasibility, we hereby address the impulsive noise characterized with excessive energy and moderately high probability of occurrence in OFDM system by means of a limiter whose clipping threshold is derived in a frequency-domain perspective based only on the probability of occurrence of impulses.…”

Section: Introductionmentioning

confidence: 99%

Efficient clipping for broadband power line systems in impulsive noise environment

2012 IEEE International Symposium on Power Line Communications and Its Applications

Yang

Tsai

et al. 2012

Self Cite

For broadband power line communication systems, which may be incorporated with Orthogonal Frequency Division Multiplexing (OFDM) technique, the detrimental effect arising from strong and frequently occurred impulses is paramount as signaling on each subcarrier is simultaneously corrupted thanks to frequencydomain transformation on a per-OFDM symbol basis at the front-end receiver. In this perspective, channel coding epoch on the basis of per-OFDM symbol cannot effect the coding gain. Recently, clipping operation on received samples has been addressed as an effective approach to mitigate this incurring performance loss subject to impulsive noise, given the knowledge of the probability density function (PDF) of impulsive noise at receiver. In this paper, we forgo the a-priori knowledge of the PDF of impulsive noise but devise the threshold to clipping, only relying on the probability of occurrence of impulses. To attest our method, we conduct computer simulations in compliance with the IEEE 1901 standard over commonly adopted memoryless impulsive noise models. Promisingly, the proposed scheme is on par with its counterpart, where the threshold of a limiter is realized by assuming the PDF of impulsive channels perfectly known to receiver. In addition, the devised clipping scheme is shown to be robust against impulses of frequent occurrence characterized by excessively high energy in the signal-to-noise ratio range of interest, regardless of the impulsive noise model assumed.