Enhanced linear interpolation for low sampling rate asynchronous channels

Abstract

Linear interpolation can be used to recover synchronous samples from asynchronous ones, replacing PLO hardware with a digital algorithm. With Enhanced Linear Interpolation, (ELI), computing additional samples midway between existing samples effectively doubles the sampling frequency. Linear interpolation is then used between the asynchronous samples and midpoint samples. The interpolation error is computed as a function of input waveform parameters, sampling frequency, and midpoint interpolator parameters, for both synchronous and asynchronous channel equalization. ELI allows the sampling rate to be below the bit rate.