Decoding method and device for FM0 coding

Abstract

The invention discloses a decoding method and device for FM0 coding. The method comprises the following steps: acquiring a digital signal of a square wave after detection in a bit window; constructinga plurality of bit windows for bits to be decoded in the digital signal; dividing each bit window into a plurality of bit window units, and determining a counting vector L and a counting vector H ofeach bit window; determining a plurality of bit window level vectors corresponding to each bit window level change according to the coding rule of the FM0; calculating a plurality of similarities corresponding to each bit window according to the counting vector L and the counting vector H of each bit window and the level vector of each bit window; determining a target bit window level vector according to the plurality of similarities corresponding to each bit window; and determining whether the bit to be decoded is successfully decoded according to the target bit window level vector. The problem that under the condition that the signal-to-noise ratio is low, a signal subjected to detection in a currently decoded bit window generates distortion to a certain degree, and consequently decodingfails is solved.

Description

technical field [0001] The present application relates to the field of decoding digital signals in wireless digital communication, in particular, to a method and device for decoding FMO codes. Background technique [0002] The full name of FM0 encoding is biphase interval encoding. The encoding rule is that all high or all low levels in the bit window represent logic "1", and if the level flip occurs within the bit window, it represents logic "0". At the same time It is required that the level at the beginning of any bit window must be flipped. Because the FM0 encoding rule is symmetrical and simple, and the encoding and decoding process is easy to realize through hardware circuits, it is widely used in 5.8G radio frequency communication such as radio frequency identification (Radio Frequency Identification, referred to as FRID) and electronic non-stop charging. [0003] The current FM0 decoding algorithm usually uses the correlation algorithm of a single symbol in the bit ...

AI Technical Summary

Problems solved by technology

[0005] The main purpose of this application is to provide a decoding method and device for FMO coding, to solve the problem of low signal-to-noise ratio in the related art. A certain degree of distortion causes the problem of decoding failure

Images