Signal to noise ratio estimation method under frequency hopping communication interference condition

Abstract

The invention discloses a signal to noise ratio estimation method under a frequency hopping communication interference condition. The signal to noise ratio estimation method comprises the following steps: at first, carrying out matched filtering on a received signal by a matched filter under the frequency hopping communication interference condition, transmitting the received signal into an energy detector to detect the energy, predicting an interference hop, and demodulating the interference hop; respectively sending the demodulated signal to an LDPC iterative decoder and a signal to noise ratio estimator, iteratively decoding the demodulated signal by the LDPC iterative decoder, sending the iterative decoding information of the signal to the signal to noise ratio estimator, estimating a signal to noise ratio through an estimation algorithm in combination with the demodulated signal information, sending an estimated value to the LDPC iterative decoder to carry out next iterative decoding, repeating the process until reaching an iteration time, and finally, outputting the estimated value. The signal to noise ratio estimation method disclosed by the invention is used for solving the problem of signal to noise ratio estimation under the conditions of high estimation precision, wide signal to noise ratio estimation range, low signal to noise ratio and very small estimation error, and plays a positive role of improving the channel state estimation accuracy during slow frequency hopping communication self-adaptive transmission.

Description

technical field [0001] The invention belongs to the field of frequency hopping adaptive transmission, and in particular relates to a signal-to-noise ratio estimation method under the interference condition of frequency hopping communication. Background technique [0002] The signal-to-noise ratio is an important parameter index in the communication system. It reflects the relative relationship between the signal and the noise, and has a direct correspondence with the performance of the system bit error rate. The basis is a kind of channel state information often used in communication systems. The link adaptive technology is to adjust the transmission signal parameters adaptively according to the state of the channel to make the communication quality meet the requirements. A typical interference in a slow frequency hopping system is partial frequency band interference. Since each frequency hopping time slot contains multiple symbols, the interference detection in this case c...

AI Technical Summary

Problems solved by technology

This method has good performance, and it is very close to the case of known channel side information under the condition that each hop contains a certain number of symbols. However, due to the large amount of calculation of the EM algorithm, the complexity of this method is high, which is not conducive to practical application

[0005] In summary, the traditional SNR estimation method has low estimation accuracy, narrow SNR estimation range, large estimation deviation in the case of low SNR, and low signal length and low SNR. Many SNR estimation methods will have large estimation bias

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