Digital trunked communication 3/4 code rate grouped data error-resisting decoding method

Abstract

The invention relates to a digital trunked communication 3 / 4 code rate grouped data error-resisting decoding method. The method comprises the steps that firstly, de-interleave is carried out on received signals to obtain dual-bit pairs, then, survival path arrays and weight arrays are initialized, state transition of all possible input states is calculated for three bits input every time, corresponding dual-bit pairs are calculated according to an FSM, and the obtained dual-bit pairs are compared with the actually-received dual-bit pairs. According to the digital trunked communication 3 / 4 code rate grouped data error-resisting decoding method, the viterbi decoding method is used, and the characteristics of the trellis coded FSM are utilized for calculating weights of transition of all the possible states for each input state, so that survival paths are picked out, and backtracking is carried out to complete decoding output. Compared with a traditional method, the high error-resisting capacity is achieved, the problem of error accumulation during traditional 3 / 4 code rate grouped data decoding is solved, the application range is wide, and the popularization value is realized.

Description

technical field [0001] The invention relates to the field of anti-error code technology of communication, in particular to an anti-error code decoding method for packet data with a coding rate of 3 / 4 in digital trunking communication. Background technique [0002] PDT (Police Digital Trunking) police digital trunking communication system standard is a digital professional wireless communication technology standard used by the public security industry in my country. The standard adopts TDMA time division multiple access mode, 4FSK modulation mode, large area system coverage, and full digital voice coding And channel coding, with flexible networking capabilities and digital encryption capabilities. [0003] PDT can implement services such as voice scheduling, short message, status message and packet data. The packet data service is a transmission method that divides messages of any length into pieces and then sends them piece by piece. The data frame of packet d...

AI Technical Summary

Problems solved by technology

[0005] In the decoding process, if the deinterleaved double bits are directly decoded by the inverse finite state machine, a bit error will lead to an error in the output state of the inverse finite state machine, and because the inverse finite state machine uses the decoding output of the previous moment as the current moment Decoding input, so it will lead to the accumulation of decoding errors

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