Digitally Controlled Analog Cancellation for Full Duplex Broadband Power Line Communications

Abstract

Although in-band full-duplexing (IBFD) has long been implemented in various communication media, it was only recently that an IBFD solution was presented for broadband power line communications (BB-PLCs). The maximum attainable echo suppression using this solution is, however, limited by the dynamic range of the analog-to-digital converter (ADC). To counter this critical constraint, we propose echo cancellation in the analog domain, while persisting with a low-complexity frequency domain digital echo estimation. By formulating an expression for the number of ADC bits lost in IBFD over a conventional half-duplex operation, we show that the ADC dynamic range is no longer a limiting factor for our solution. We further extend our solution to present an analog cancellation method for multiple-input multiple-output IBFD BB-PLC systems. Finally, we present simulation results of echo cancellation and data rate gains obtained under realistic in-home BB-PLC settings, to demonstrate that our solution is capable of doubling bidirectional transfer rates in a large number of the tested network conditions.