Patent ID: 8448054

Claim:
A transmitter apparatus, comprising: an input coupled to receive an input bit sequence that comprises input bits; a state tracker that keeps track of a current state of a transmission signal; a bit-to-phase mapper configured to map a first subset of the input bits to a set of state transition signals in accordance with a first mapping, and to map a second subset of input bits to the set of state transition signals in accordance with a second mapping that is inverted with respect to the first mapping, wherein the selection of the first mapping and the second mapping is made based upon the current state of the transmission signal, and the bit-to-phase mapper is further configured to reduce, relative to a system that just uses the first bit mapping function, a measure of Hamming distance between merging trellis paths associated with merging events that have minimum Euclidian distance in a signal trellis associated with the transmission signal; and a modulator that uses the state transition signals to produce the transmission signal for being transmitted over a communication channel; wherein the transmitter apparatus provides a physical layer interface to the communication channel and the transmitter apparatus provides a coupling of the transmission signal onto the communication channel for communication with a remotely located communications device.