  In this letter, a compressed relaying scheme via Huffman and physical-layer
network coding (HPNC) is proposed for two-way relay networks with correlated
sources (TWRN-CS). In the HPNC scheme, both sources first transmit the
correlated raw source messages to the relay simultaneously. The relay performs
physical-layer network coding (PNC) on the received symbols, compresses the
PNC-coded symbols using Huffman coding, and broadcasts the compressed symbols
to both source nodes. Then, each source decodes the other source's messages by
using its own messages as side information. Compression rate and block error
rate (BLER) of the proposed scheme are analyzed. Simulation results demonstrate
that the HPNC scheme can effectively improve the network throughput, and
meanwhile, achieve the superior BLER performance compared with the conventional
non-compressed relaying scheme in TWRN-CS.
