This paper presents an efficient blind channel estimation technique for orthogonal frequency division multiplexing (OFDM) systems over-time varying channels. New frame structure is proposed, where different modulation schemes are employed to estimate the time-varying channel coefficients. Amplitude shift keying (ASK) and phase shift keying (PSK) modulation schemes are utilized to modulate particular pair of subcarriers over consecutive OFDM symbols, where the ASK and PSK symbols cooperate to enable blind estimation of the channel coefficients. In particular, PSK modulated symbols are employed in the amplitude- coherent detector (ACD) to allow blind detection for the ASK symbols. After that, the detected ASK symbols, with interpolation, are used to estimate the channel coefficients for the full frame. Exact closed-form expression for the symbol error rate (SER) of the ASK symbols is derived and corroborated with Monte Carlo simulations to evaluate the performance of the proposed technique and compare it with the pilot based OFDM system. Analytical and simulation results show that the proposed estimator can provide estimation with accuracy and computational complexity that are comparable to pilot based estimators.
Blind Channel Estimation Technique for OFDM Systems over Time Varying Channels
2018-06-01
229073 byte
Conference paper
Electronic Resource
English
British Library Online Contents | 2002
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