1Department of Electronics and Communication Engineering, National Institute of Technology, Calicut, Kerala, India.
2Department of Electronics and Communication Engineering, National Institute of Technology, Calicut, Kerala, India.
3Department of Electronics and Communication Engineering, National Institute of Technology, Calicut, Kerala, India.
The IEEE 802.11 based wireless local area networks (WLANs) have enjoyed popularity in many segments. Enhancements to the standards have been ongoing resulting in various flavors of the standard. IEEE 802.11n task group (TGn) was formed with the goal of increasing the application throughput to at least 100Mbps by making changes in the PHY and MAC layer. The major change in the PHY layer is the use of multiple transmit and receive antennas along with the OFDM system to support several parallel streams. The multiple input multiple output (MIMO) systems offer very higher data rates in the same bandwidth as compared to the single input single output (SISO) systems. This work focuses on studying the challenges and issues in the MIMO-OFDM systems and proposing new techniques to solve the problems with the orientation towards the IEEE 802.11n standard. The detection of data in MIMO-OFDM systems is a key challenge as we need parallel MIMO detectors on the subcarriers. This results in a system with a large computational complexity. We propose low complexity MIMO-OFDM detectors whose idea is to reduce the number of MIMO detectors applied for detecting the data in all the subcarriers by considering the IEEE 802.11n channel conditions. The proposed detector offers a complexity reduction of about 50. The BER and PER performance show that the low complexity (LC) MIMO-OFDM detectors are suitable for the IEEE 802.11n based WLANs in practical channel conditions.
MIMO systems, low complexity detection, spatial multiplexing, orthogonal frequency division multiplexing, mean-square error, ML detection
