Patent ID: 7221711

Claim:
A multilevel data encoding and modulation method for data transmission of a bit stream sequence of binary data, comprising the steps of: (a) separating a bit stream sequence of binary data into odd-numbered bits and even-numbered bits based upon a bit's order in the sequence; (b) assigning a voltage level to the odd-numbered bits from a first set of voltage levels, the first set having a unique voltage level correlating to each available logic level; (c) assigning a voltage level to the even-numbered bits from a second set of voltage levels, the second set having a unique voltage level correlating to each available logic level, wherein the second set of voltage levels is symmetrically disposed about a median level from the first set of voltage levels; and (d) combining the voltage levels assigned to the odd-numbered bits with the voltage levels assigned to the even numbered bits in order to form an aggregate bit stream, successive bits in the bit stream alternately disposed about the median voltage level; whereby said bit stream defines a baseband signal having a constant frequency.