22-02-2013, 11:01 AM
Efficient SNR Estimation in OFDM System
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INTRODUCTION
It is very important to estimate the signal to noise ratio
(SNR) of received signal and to transmit.
The performance of existing non-data-aided (NDA) SNR estimation methods are substantially degraded for high level modulation.
we propose a SNR estimation method which uses zero point auto-correlation of received signal per block and auto/cross- correlation of decision feedback signal in orthogonal frequency division multiplexing (OFDM) system.
Proposed method can be studied into two types;
Type 1 can estimate SNR by zero point auto-correlation of decision feedback signal based on the second moment property.
Type2 uses both zero point auto-correlation and cross-correlation based on the fourth moment property.
In block-by-block reception of OFDM system, these two SNR estimation methods can be possible for the practical implementation due to correlation based the estimation method
And they show more stable estimation performance than the previous SN estimation methods.
Frequency-Domain
Frequency Domain Equalizer is a techniques that exhibits the property of relatively low complexity growth with increasing channel dispersion.
Single-Carrier Frequency Domain Equalizer has been accepted as an option in the up link wireless broadband standard IEEE 802.16 .
Conclusion
From this study we can note the importance of an equalization technique.
Linear and decision feedback (DF) equalization techniques are used in this study.
but we note the decision feedback equalization (DFE) performs better than linear equalization (LE).