Adaptive demodulation method and apparatus using an artificial neural network to improve data recovery in high speed channels

Abstract

A neural network demodulator is used within a receiver to provide Inter Symbol Interference (ISI) channel equalization and to correct for I/Q/phase imbalance. The neural network is trained with a single integrated training step to simultaneously handle the channel impairments of ISI equalization and I/Q phase imbalance as opposed to prior art methods of separately addressing each channel impairment in sequence.

Description

RELATED APPLICATIONS[0001]This application is a continuation-in-part of U.S. patent application Ser. No. 14 / 312,072, filed Jun. 23, 2014, hereby incorporated herein by reference, and U.S. Provisional Patent Application No. 61 / 837,742, filed Jun. 21, 2013.FIELD OF THE INVENTION[0002]The present invention relates to a neural network based integrated demodulator that mitigates channel impairments, ISI and I / Q channel leakages, and minimizes the impact on the overall performance of the system. In this process, the inventive demodulator improves the performance for data recovery when operating at high data rates over the transmission channel.BACKGROUND OF THE INVENTION[0003]High-Speed communications systems typically use a wide band channel where the transmission is achieved using Radio Frequency (RF) carriers. RF transmission as it exists today either uses closely spaced narrow band multiple carriers or a small number of carriers containing baseband modulated signals.[0004]An example of...

AI Technical Summary

Benefits of technology

[0024]a. The method to nullify or mitigate the effect of channel response by employing a training period to initialize the channel equalizer that has a simple adaptive system. Some techniques in this category include also a blind equalization technique without a training period by employing different and possible-to-estimate channel characteristics.

[0025]b. For OFDM channels, which use a narrow fre

Problems solved by technology

In both of the above scenarios, the performance of high-speed digital transmission suffers high degradation due to the effects of channel impairments.

Specifically, the channel impairments, which include Inter-Symbol-Interference and the leakage of I/Q modulated signals, which are sent over each of the RF carriers, significantly degrades the Bit Error Rate (BER) performance.

In a small number of carrier based systems, both wireline and wireless channels experience leakage of I/Q due to imperfect phase imbalance.

As the transmit systems carry large data rates, the sensitivity to these channel impairments become significant.

Also, there could be bottlenecks in the design process to achieve optimal system performance, when these two impairments are handled

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