Open AccessBandwidth‐Efficient Selective Retransmission for MIMO‐OFDM Systems
Author(s) -
Zia Muhammad,
Kiani Tamoor,
Mahmood Hasan,
Shah Tariq,
Saqib Nazar A.
Publication year - 2015
Publication title -
etri journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.295
H-Index - 46
eISSN - 2233-7326
pISSN - 1225-6463
DOI - 10.4218/etrij.15.0114.0050
Subject(s) - retransmission , orthogonal frequency division multiplexing , hybrid automatic repeat request , mimo ofdm , subcarrier , computer science , mimo , electronic engineering , channel (broadcasting) , throughput , carrier frequency offset , multiplexing , computer network , wireless , real time computing , engineering , network packet , telecommunications link , frequency offset , telecommunications
In this work, we propose an efficient selective retransmission method for multiple‐input and multiple‐output (MIMO) wireless systems under orthogonal frequency‐division multiplexing (OFDM) signaling. A typical received OFDM frame may have some symbols in error, which results in a retransmission of the entire frame. Such a retransmission is often unnecessary, and to avoid this, we propose a method to selectively retransmit symbols that correspond to poor‐quality subcarriers. We use the condition numbers of the subcarrier channel matrices of the MIMO‐OFDM system as a quality measure. The proposed scheme is embedded in the modulation layer and is independent of conventional hybrid automatic repeat request (HARQ) methods. The receiver integrates the original OFDM and the punctured retransmitted OFDM signals for more reliable detection. The targeted retransmission results in fewer negative acknowledgements from conventional HARQ algorithms, which results in increasing bandwidth and power efficiency. We investigate the efficacy of the proposed method for optimal and suboptimal receivers. The simulation results demonstrate the efficacy of the proposed method on throughput for MIMO‐OFDM systems.