Distributed modem architectures for power line communication systems and other wired communication systems

A method of communicating over a DC power line forming a wiring loop for DC current, the method operable with a distributed modem architecture that includes at least one active node and at least one passive node (collectively, nodes), comprising:

• AC coupling each active node and each passive node to the power line wiring loop through respective active and passive node couplers that are tuned to an AC carrier signal, and that enable substantially continuous DC current flow through the power line wiring loop,
• generating, at the active node, the AC carrier signal with an AC carrier frequency, coupled into the power line wiring loop through the active node coupler;
• receiving, at the passive node, the AC carrier signal;
• communicating data, from a transmitting passive node to at least one receiving node, at the AC carrier frequency within an AC carrier frequency band by:
• changing at a transmitting passive node, the AC impedance of the associated passive node coupler, and thereby changing an AC impedance of the power line wiring loop within the AC carrier frequency band, wherein the AC impedance of the power line wiring loop is changed within the AC carrier frequency band based on data to be transmitted by the transmitting passive node so as to modulate the data onto the AC carrier signal within the AC carrier frequency band;
• detecting, at the receiving node, the change in the AC impedance of the power line wiring loop, and thereby detecting the modulated data.