Dirty paper coding
||This article may be too technical for most readers to understand. (September 2010)|
In telecommunications, dirty paper coding (DPC) is a technique for efficient transmission of digital data through a channel subjected to some interference known to the transmitter. The technique consists of precoding the data in order to cancel the effect caused by the interference.
The term 'dirty paper coding' comes from Max Costa who imagined a paper which is partially covered with dirt that is indistinguishable from ink. The theorem says that if the writer knows where the dirt is to start with, she can convey just as much information by writing on the paper as if it were clean, even though the reader does not know where the dirt is. In this case the dirt is interference, the paper is the channel, the writer on the paper is the transmitter, and the reader is the receiver. In information-theoretic terms, dirty-paper coding achieves the channel capacity, without a power penalty and without requiring the receiver to gain knowledge of the interference state.
Instances of dirty paper coding include Costa precoding (1983). Suboptimal approximations of dirty paper coding include Tomlinson-Harashima precoding (1971)  and the vector perturbation technique of Hochwald et al. (2005).
DPC and DPC-like techniques requires knowledge of the interference state in a non causal manner, such as channel state information of all users and other user data. Hence, the design of a DPC-based system should include a procedure to feed side information to the transmitters.
In 2003, Caire and Shamai  applied DPC to the multi-antenna multi-user downlink, which is referred to as the 'broadcast channel' by information theorists. Since then, there has been widespread use of DPC in wireless networks and into an interference aware coding technique for dynamic wireless networks.
Recently, DPC has also been used for "informed digital watermarking".
- Multiple-input multiple-output communications
- Advanced MIMO communications
- Cognitive radio
- M. Costa (May 1983). "Writing on dirty paper". IEEE Trans. Information Theory 29 (3): 439–441. doi:10.1109/TIT.1983.1056659.
- M. Tomlinson (March 1971). "New automatic equalizer employing modulo arithmetic". Electron. Lett. 7 (5–6): 138–139. doi:10.1049/el:19710089.
- H. Harashima and H. Miyakawa (August 1972). "Matched-transmission technique for channels with intersymbol interference". IEEE Trans. Commun. COM-20: 774–780.
- B. M. Hochwald, C. B. Peel, and A. L. Swindlehurst (March 2005). "A vector-perturbation technique for near-capacity multiantenna multiuser communication - Part II: Perturbation". IEEE Trans. Commun. 53 (3): 537–544. doi:10.1109/TCOMM.2004.841997.
- Caire, Guissepe; Shamai, Shlomo (July 2003). "On the Achievable Throughput of a Multiantenna Gaussian Broadcast Channel". IEEE TRANSACTIONS ON INFORMATION THEORY 49 (3).
- C. T. K. Ng and A. Goldsmith (October 2004). "IEEE Information Theory Workshop". San Antonio, Texas. pp. 277–282.
- Momin Uppal, Zhixin Liu, Vladimir Stankovic, Anders Høst-Madsen and Zixiang Xiong (February 2007). "Information theory and applications".