Methods and systems for transmitting data by modulating transmitter filter coefficients

摘要

A signaling system supports main and auxiliary communication channels between integrated circuits in the same direction over a single link. An equalizing transmitter applies appropriate filter coefficients to minimize the impact of intersymbol interference when transmitting the main data over a communication channel. The transmitter modulates at least one of the filter coefficients with the auxiliary data to induce apparent ISI in the transmitted signal. A main receiver ignores the apparent ISI to recover the main data, while an auxiliary receiver detects and demodulates the apparent ISI to recover the auxiliary data. The auxiliary data may be encoded using spread-spectrum techniques to reduce the impact of the auxiliary data on the main data.

主权项

1. A circuit comprising:
a transmitter including a first data-input node to receive a first data signal, a first data output node, and a first filter-coefficient input node; a modulator including a second data-input node to receive a second data signal, a second filter-coefficient input node; and a modulator output node coupled to the first filter-coefficient input node; and a filter-coefficient source having a filter-coefficient output node coupled to the second filter-coefficient input node to convey filter coefficients; wherein the modulator modulates the filter coefficients with the second data signal to generate modulated second data and conveys the modulated second data from the modulator output node to the first filter-coefficient input node.