Simultaneous bidirectional signaling with adaptive pre-emphasis

This paper presents a novel design for a simultaneous bidirectional signaling system with an adaptive pre-emphasis feature. The feedback loop inherent in a simultaneous bidirectional link provides a natural opportunity to use adaptive pre-emphasis to compensate for channel characteristics. The system determines the degree of corruption of a received signal and generates a pulse width modulated signal which gets sent back through the bidirectional link to control the amount of pre-emphasis that is used. The technique has been verified using Cadence SpectreRF and Verilog-A simulators, where the channel loss characteristics are based on an FR-4 material model. The simulation results show that the system automatically selects the best fit for the observed channel loss compensation, which then reduces the efforts needed to recover the data at each receiver.