Advanced Metering Infrastructure (AMI) system carrier communication module self-adaptive modulation and coding method

Abstract

The invention discloses an advanced metering infrastructure (AMI) system carrier communication module self-adaptive modulation and coding method. The method comprises the following steps of inputting a code stream through a forward error correction coder to a serial-parallel converter; converting the serial data to a parallel code stream through the serial-parallel converter; setting a comparison threshold, and carrying out the threshold comparison between a subcarrier channel estimation value and a threshold comparative value; determining a subchannel modulation mode through a subchannel according to a comparison result; and modulating the subchannel according to the determined subchannel modulation mode. The modulation way of each subchannel is adaptively adjusted according to the signal-to-noise ratio, and corresponding demodulation is carried out on a receiving end; a modulation way with strong robustness is used for the subchannel with severe noise interference so as to improve the interference resistance; a modulation and coding way is determined according to the signal-to-noise ratio of the subchannel, higher transmission power is allocated to the subchannel with a high signal-to-noise ratio, and a modulation way with a high transmission rate is adopted; and the transmission efficiency and the interference resistance of the entire system can be improved.

Description

technical field [0001] The invention relates to modulation and encoding methods, in particular to an adaptive modulation and encoding method for the carrier communication module of an AMI system. Background technique [0002] The existing multi-carrier communication module of the automatic meter reading system implements G3 standard OFDM power line carrier communication technology and PRIME standard OFDM power line carrier communication technology. The physical layer of the PRIME standard is similar to the G3 standard, so here we take the G3 standard as an example to illustrate the shortcomings of the prior art. The physical layer of the G3 standard adopts the same modulation method for all subcarriers in the baseband modulation method at the sending end. For subchannels with severe noise interference, the error rate is high and the transmission efficiency is low. There is no need to judge at the receiving end, and the same demodulation mode is adopted for all subcarriers. ...

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Problems solved by technology

In this way, although the algorithm is simple to operate and does not require pre-estimation of the channel conditions at the receiving end, for sub-channels with severe channel interference, its information will be severely damaged, or the transmission efficiency is extremely low. The main disadvantages are as follows:

[0003] 1. The robustness of subcarriers with relatively large noise interference will be weakened, so transmission errors are serious and transmission efficiency is low

[0004] 2. For subcarriers with high signal-to-noise ratio, using low-efficiency modulation will waste bandwidth

[0005] 3. All subcarriers use the same modulation and demodulation method, which will reduce the transmission efficiency and anti-interference ability of the entire system

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