Patent ID: 8315152

Claim:
A system comprising: a first network device including a first receiver and a first transmitter that operate in a frequency band from 1 kHz to 600 kHz, wherein the first transmitter includes: an encoding module including an interleaver to interleave transmit data in both time and frequency and to operate in a plurality of modes including a first mode and a second mode, the interleaver to perform repetitive encoding on the transmit data in the second mode; and a modulation module in communication with the encoding module, the modulation module including: an adaptive tone mapping module to modulate an output of the encoding module to selected orthogonal tones located in the frequency band based on a mapping table; and a frequency pre-emphasis module to pre-emphasize at least one of the selected orthogonal tones to compensate for estimated attenuation during propagation of a transmitted signal; a high-voltage/low-voltage (HV/LV) transformer connected by a power line to the first network device; and a second network device connected by the power line to the HV/LV transformer, wherein the second network device: comprises a second transmitter and a second receiver, performs channel estimation based on the transmitted signal, and selectively adjusts the mapping table and pre-emphasis of the first transmitter based on channel estimation, and wherein the first network device and the second network device communicate data via the power line through the HV/LV transformer in the frequency band from 1 kHz to 600 kHz.