Implementation of high precision and low cost SNR estimator for wireless OFDM system

Signal-to-Noise Ratio is regarded as an important parameter for link quality measurement. Focusing on wireless local area network, this paper proposes a SNR measurement using the same frequency domain symbols transmitted in orthogonal frequency division multiplexing system of the physical layer, for instance, the two same parts in the long training sequence. The results show that the estimator is more accurate and lower complicated than methods of time domain and pilot-aided, and it works well both in Additive White Gaussian Noise and multipath fading channel. We adapt Time Division Multiplexing of Multiplier Processor to reduce hardware cost and present Shortened Logarithm Look Up Table Processor to get the base-10 logarithm operation in SNR estimator. The implementation on Field Programmable Gate Array indicates that it can match with the simulation results and provide a good estimation for the development platform of wireless local area network.