Toward a Practical Scheme for Binary Broadcast Channels with Varying Channel Quality Using Dirty Paper Coding

• Published in: IEEE transactions on communications Vol. 59; no. 4; pp. 1009 - 1018
• Main Authors: Kyung, Gyu Bum, Wang, Chih-Chun
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.04.2011; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Broadcast channels (BCs); Broadcasting; Channels; Coding; Coding, codes; Complexity; Complexity theory; Decoding; Design engineering; dirty paper coding (DPC); Encoding; Exact sciences and technology; Information, signal and communications theory; Iterative decoding; low-density parity-check (LDPC) codes; Quantization; Receivers; Sampling, quantization; Signal and communications theory; Telecommunications and information theory; Time sharing; time-varying channels; Performance evaluation; Binary channel; State of the art; Binary system; dirty paper coding (DPC); System design; Channel coding; Flexibility; Binary coding; Non uniform distribution; Implementation; Broadcast channels (BCs); iterative decoding; Time sharing system; low-density parity-check (LDPC) codes; Signal quantization; time-varying channels; Broadcast channels
• ISSN: 0090-6778; 1558-0857
• DOI: 10.1109/TCOMM.2011.020411.090340

We consider practical schemes for binary dirty-paper channels and broadcast channels (BCs) with two receivers and varying channel quality. With the BC application in mind, this paper proposes a new design for binary dirty paper coding (DPC). By exploiting the concept of coset binning, the complexity of the system is greatly reduced when compared to the existing works. Some design challenges of the coset binning approach are identified and addressed. The proposed binary DPC system achieves similar performance to the state-of-the-art, superposition-coding-based system while demonstrating significant advantages in terms of complexity and flexibility of system design. For binary BCs, achieving the capacity generally requires the superposition of a normal channel code and a carefully designed channel code with non-uniform bit distribution. The non-uniform bit distribution is chosen according to the channel conditions. Therefore, to achieve the capacity for binary BCs with varying channel quality, it is necessary to use quantization codes of different rates, which significantly increases the implementation complexity. In this paper, we also propose a broadcast scheme that generalizes the concept of binary DPC, which we term soft DPC. By combining soft DPC with time sharing, we achieve a large percentage of the capacity for a wide range of channel quality with little complexity overhead. Our scheme uses only one fixed pair of codes for users 1 and 2, and a single quantization code, which possesses many practical advantages over traditional time sharing and superposition coding solutions and provides strictly better performance.