A Compressive Sampling-Based Channel Estimation Method for Network Visibility Instrumentation

This article proposes a novel method to estimate the frequency response of cables for applications of physical layer testing and network visibility. By exploiting compressive sampling, the method allows using analog-to-digital converters with a sampling frequency much lower than the symbol rate of the transmitted bit stream. Moreover, it does not need a properly generated signal, as it happens in time-domain reflectometry; however, any signal having a pulse-amplitude modulation, orthogonal frequency-division multiplexing (OFDM), or spread spectrum modulation can be used. Therefore, the transceiver actually used for data transmission can also be used to generate test signals for the channel estimation and the measurement instrument can be integrated into the data communication equipment without requiring additional generators. The mathematical formulation of the method is presented, together with its evaluation by numerical simulations and experimental tests. The results show the capability of the method of properly estimating the frequency response of the channel, even with a sampling frequency much lower than the symbol frequency.