Abstract
We consider the design of near-capacity-achieving error-correcting codes for a discrete multitone (DMT) system in the presence of both additive white Gaussian noise and impulse noise. Impulse noise is one of the main channel impairments for digital subscriber lines (DSL). One way to combat impulse noise is to detect the presence of the impulses and to declare an erasure when an impulse occurs. In this paper, we propose a coding system based on low-density parity-check (LDPC) codes and bit-interleaved coded modulation that is capable of taking advantage of the knowledge of erasures. We show that by carefully choosing the degree distribution of an irregular LDPC code, both the additive noise and the erasures can be handled by a single code, thus eliminating the need for an outer code. Such a system can perform close to the capacity of the channel and for the same redundancy is significantly more immune to the impulse noise than existing methods based on an outer Reed-Solomon (RS) code. The proposed method has a lower implementation complexity than the concatenated coding approach.
Highlights
The design of error control codes for discrete multitone (DMT) systems is of great interest for applications such as digital subscriber lines (DSL) [1,2,3,4,5,6]
The main focus of this paper is the design of low-density parity-check (LDPC) codes for a DMT system in an impulse-noise environment
We have shown that a carefully optimized LDPC code is a promising candidate coding approach in DMT systems with impulsive noise
Summary
The design of error control codes for discrete multitone (DMT) systems is of great interest for applications such as digital subscriber lines (DSL) [1,2,3,4,5,6]. The use of turbo codes and LDPC codes in DMT systems is not yet widespread. This is in part due to the fact that the effect of impulse noise on turbo or LDPC codes has not yet been studied in depth. The main focus of this paper is the design of LDPC codes for a DMT system in an impulse-noise environment. The main idea of multilevel coding [12] is to label each point of a nonbinary constellation A = {a0, a1, . Bl−1) and use binary codes to protect each address bit bi by an individual binary code Ci at level i [21]. Bl−1) as the vector of random variables corresponding to the address bits.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
