Receive diversity for mobile OFDM systems

Abstract

Absrrucr-In the present paper we investigate receive diversity for OFDM-based broadband communication systems. We consider the use of multiple antennas to combat time-selective fading and OFDM transmission in combination with an appropriate guard interval to suppress intersymbol interference. The receive diversity scheme is located in the frequency-domain and we derive different linear estimators, hereafter referred to as diversity equalizers. We show that the carrier-based solution for the optimum linear MMSE estimatorwhich is the least complex solution that maximizes the overall SNRis the well known maximum ratio combiner (MRC). Furthermore, we present a performance analysis for the proposed diversity equalizers and compare theoretical results to a simulated system which uses channel state information for MRC.

BEM Reference Signal Estimation for an Airborne Passive Radar Antenna Array

“…The probability that each receiver channel faces simultaneously a deep fade lowers as N RX increases -( [43], chapter 13.4). As a consequence, antenna diversity techniques contribute to face ICI [44]. By weighting properly each array channel, these methods aim at optimizing different output parameters such as Signal-to-Noise Ratio (SNR).…”

“…By weighting properly each array channel, these methods aim at optimizing different output parameters such as Signal-to-Noise Ratio (SNR). It is the case for Maximum Ratio Combining [44], [45]. Here we propose to focus the antenna beam in the direction provided by the maximum eigenvalue of the received signal covariance matrixR yaya :…”

Blind channel estimation for multiple antenna OFDM system subject to unknown carrier frequency offset

“…The OFDM system with a multiple antenna receiver offers receive diversity to overcome fading, and it has been applied to some communication systems [22,23]. Similar as the SISO-OFDM systems, the one with multiple antenna diversity receivers also requires the channel estimation for coherent detection.…”

Multiple Invariance MUSIC-Based Blind Carrier Frequency Offset Estimation for OFDM System with Multi-Antenna Receiver

“…Practically, the OFDM system with multiple-antenna receiver providing receive diversity to overcome fading [14] has been adopted by many communication systems, such as digital video broadcasting for handheld (DVBH) [15] and future mobile wireless communications [16], etc. Similar as the single-input-single-output (SISO) OFDM systems, the one with multiple-antenna diversity receivers also appears to be sensitive to carrier synchronization errors.…”