Multipair Two-Way Half-Duplex DF Relaying with Massive Arrays and Imperfect CSI

Chuili Kong, Caijun Zhong, Michail Matthaiou, Emil Björnson, Zhaoyang Zhang

Research output: Contribution to journalArticlepeer-review

17 Citations (Scopus)
534 Downloads (Pure)


This paper considers a two-way half-duplex decodeand-forward relaying system where multiple pairs of single antenna users exchange information via a multiple-antenna relay. Assuming that the channel knowledge is non-ideal and the relay employs maximum ratio processing, we derive a large-scale approximation of the sum spectral efficiency (SE) that is tight when the number of relay antennas, M, becomes very large. Furthermore, we study how the transmit power scales with M to maintain a desired SE. In particular, three special power-scaling cases are discussed and the corresponding asymptotic SE is deduced with clear insights. Our elegant power-scaling laws reveal a tradeoff between the transmit powers of the user/relay and pilot symbol. Finally, we formulate a power allocation problem in terms of maximizing the sum SE and obtain a local optimum by solving a sequence of geometric programming problems.
Original languageEnglish
Pages (from-to)3269–3283
Number of pages15
JournalIEEE Transactions on Wireless Communications
Issue number5
Early online date01 Mar 2018
Publication statusPublished - 01 May 2018


Dive into the research topics of 'Multipair Two-Way Half-Duplex DF Relaying with Massive Arrays and Imperfect CSI'. Together they form a unique fingerprint.

Cite this