Dirty paper coding using “sum codes”

While the information theoretic result commonly referred to as “dirty paper coding” [1] has been known for long, it has not led to practical schemes that can be implemented easily in real-life communication systems. In this paper, we present the concept of sum codes and show how they provide a convenient platform for dirty paper coding. Comb-combined sum codes, which provide a convenient method of sum-code construction, are particularly useful in this respect. One can build comb-combined sum codes based on any linear block code to achieve reduction in the transmit energy required to attain a desired performance. Using an example based on tail-biting convolutional codes, we show how practical dirty paper coding may be implemented using any convenient linear block code.