Signal-noise ratio estimation method for signal of orthogonal frequency division multiplexing communication system

The invention discloses a method for estimating the signal noise ratio of an orthogonal frequency division multiplexing communication system, belonging to the orthogonal frequency division multiplexing communication technical field. The method comprises utilizing the character of the orthogonal frequency division multiplexing signal such as the frequency domain exists idle sub carrier, calculating the signal energy on the idle sub carrier after converting an OFDM symbol to frequency domain to estimate the power spectrum density of Gaussian white noise in the received signal, thereby calculating the energy of the signal and attaining an approximate signal noise ratio estimated value of the prior signal. The method estimating the signal noise ratio of the signal of an orthogonal frequency division multiplexing communication system has simple calculation, fast and simple process, which only demands to calculate the energies of the signals at the corresponding positions on the useful sub carrier and the idle sub carrier, at the time extracting frequency domain data, and adopts simple estimation algorism to attain accurate signal noise ratio estimated value.