Short Message Noisy Network Coding With a Decode–Forward Option

Abstract

Short message noisy network coding (SNNC) differs from long message noisy network coding (LNNC) in that one transmits many short messages in blocks rather than using one long message with repetitive encoding. Several properties of SNNC are developed. First, SNNC with backward decoding achieves the same rates as SNNC with offset encoding and sliding window decoding for memoryless networks where each node transmits a multicast message. The rates are the same as LNNC with joint decoding. Second, SNNC enables early decoding if the channel quality happens to be good. This leads to mixed strategies that unify the advantages of decode-forward and noisy network coding. Third, the best decoders sometimes treat other nodes' signals as noise and an iterative method is given to find the set of nodes that a given node should treat as noise sources.

Coding schemes for discrete memoryless multicast networks with rate-limited feedback

“…Recall the NNC scheme [5], [6] for DM multicast networks without feedback, where each node (including the transmitter) compresses its observation and sends the new compression index in the next block. Comparing our coding scheme with NNC, we observe that both schemes involve block Markov coding, compressing channel outputs and sending compression messages.…”

“…Both strategies have been generalized to multiple-relay channels [3]. The compressforward was later extended to a more general network-discrete memoryless networks [4], [5], [6], called noisy network coding (NNC). Recently, a distributed decode-forward coding (DDF) scheme was proposed for multicast [7] and broadcast relay networks [8], which uses the partial decode-forward at the relays and backward coding at the transmitter.…”

“…Our strategy is reminiscent of the noisy network coding for general networks [5], [6] in the sense the relays and receivers compress their channel outputs and send these compression indices over the feedback links. However, our schemes have the transmitter forward the receivers and relays' compression messages, instead of creating a new compression message.…”

Coding schemes for discrete memoryless multicast networks with and without feedback

“…Both strategies have been generalized to multiplerelay channels in [3]. The compress-forward strategy was later extended to multi-message multicast and multi-messages networks, called noisy network coding (NNC) [4], [5], [6]. Recently, a distributed decode-forward coding (DDF) scheme was proposed for multicast [7] and broadcast relay networks [8], which uses the partial decode-forward strategy at the relays and backward coding at the transmitter.…”

“…Our coding scheme is reminiscent of the noisy network coding for general networks [5], [6] in the sense the relays and receivers compress their channel outputs and send these compression indices over the feedback links. However, we introduce combined compress-forward and partial decodeforward strategy into the relays.…”