METHOD OF TRANSMITTING DISCRETE MESSAGES USING A QUADRATURE INTRA-PULSE PHASE MODULATION
The article describes a method for transmitting discrete messages using quadrature intra-pulse phase modulation (QIPM), which allows to increase the noise immunity of message transmission over various communication channels, including those with rapidly changing parameters, for example, through channels with pseudo-random operational frequency readjustment (FHSS). It is demonstrated that the noise immunity of a modem with QIPM exceeds the noise immunity of currently widely used modems with QAM, AM, FM and DPSK. This problem is solved due to the intra-pulse phase modulation of the carrier oscillation quadratures by mutually orthogonal binary sequences and their synphasing at the receiving end of the radio line. A unique feature of a modem with QIPM is almost a complete absence of errors and erasure of invalid code combinations at its output.