Patent ID: 7433415

Claim:
Method for transmission of QAM (quadrature amplitude modulation) signals to be applied in telecommunication networks for any data rate at the signal to noise ratio below 0 dB, the method comprising the following steps: converting an initial information bit sequence with a clock frequency f t into an m level sequence with a clock frequency f t /k, where k=log 2 (m); converting the m-level sequence into a sequence of m-level short pulses with an off duty factor greater than 2; forming a first channel and a second channel by dividing of m-level short pulses with the clock frequency f t /2k into even and odd sequences, respectively; summing up a signal of the first channel with a constant component; multiplying the signal of the first channel with signal Cos ( 2 ⁢ π ⁢ f t 4 ⁢ k ⁢ t ) , and a signal of the second channel with signal Sin ( 2 ⁢ π ⁢ f t 4 ⁢ k ⁢ t ) , respectively; filtering the signal of the first channel and the signal of the second channel and extracting frequency components from 0 to f t 4 ⁢ k ; multiplying the signal of the first channel with Cos ω 0 t, and the signal of the second channel with signal Sin ω 0 t, where ω 0 2 ⁢ ⁢ π - is a carrier frequency, and obtaining result signals of the first and the second channels; and summing up the result signals and forming the signal for transmission.