Patent ID: 7391819
Filing Date: 2008-06-24
Classification: H04L

Abstract:
1. A method for implementation of Quadrature Parallel-Layered Modulation (QLM) for communications over the same frequency bandwidth of a carrier frequency, said method comprising the steps: generating a first communications signal over the frequency bandwidth at the carrier frequency for the first channel by modulating a first stream of data symbols with a waveform at a 1/T generating a second communications signal over the same frequency bandwidth at the same carrier frequency for a second channel by modulating a second stream of data symbols with the same waveform at the same symbol rate as the first stream of data symbols and with a time offset ΔT for any additional channels, continuing generation of communication signals over the same frequency bandwidth at the same carrier frequency by modulating additional streams of data symbols with the same waveform at the same data symbol rate as the first and second streams of data symbols, with time offsets increasing in each communication signal in increments of ΔT transmitting and receiving said communications signals over a QLM communications link consisting of the n combining said algorithm with error correction decoding to recover the transmitted information; whereby time offsets have been used as a differentiating parameter to enable QLM parallel channels of communications over the same frequency bandwidth at the same carrier frequency with a data symbol rate above the Nyquist rate, to be demodulated, wherein the communication signals have the following properties: maximum capacity “C” in bits/second is defined by equation wherein the maximum “max” is with respect to n p , “log 2 ” is the logarithm to the base 2, “B” is the frequency bandwidth in Hz, and “S/N” is the ratio signal-to-noise over “B”, maximum number of bits “b” per symbol interval T maximum communications efficiency “η” in Bits/second/Hz is defined by equation minimum signal-to-noise ratio per bit “E wherein “E b ” is the energy per bit, “N o ” is the power spectral density of the noise, and the minimum “min” is the minimum with respect to n p , and wherein these performance bounds apply to communications receiver demodulation performance of a QLM communications link consisting of n