Constant envelope modulation communication system

A method for encoding a first symbol and a second symbol on a phase component of a carrier signal, the first symbol being transmitted during a first symbol transmission interval, the second symbol being transmitted during a second symbol transmission interval overlapping the first symbol transmission interval, said method comprising

• filtering the first symbol with a first transmitting-filter-function in a first interval, thereby generating a first weighted signal,
• filtering the second symbol with a second transmitting-filter-function in a second interval overlapping the first interval, thereby generating a second weighted signal,
• generating a modulating quantity on the basis of at least the first weighted signal and the second weighted signal, and
• modulating the phase component of the carrier signal on the basis of the modulating quantity, wherein the first symbol is modulated during a symbol start period that is adjacent to a symbol start period associated with the modulation of the second symbol.

A transmitter for encoding a first symbol and a second symbol on a phase component of a carrier signal, the first symbol being transmitted during a first symbol transmission interval, the second symbol being transmitted during a second symbol transmission interval overlapping the first symbol transmission interval, the transmitter comprising

• a first transmitting-filter-response generator for generating a first transmitting-filter-response in a first interval,
• a first mixer connected to receive the first transmitting-filter-response and the first symbol, thereby generating a first weighted signal,
• a second transmitting-filter response generator for generating a second transmitting-filter response in a second interval overlapping the first interval,
• a second mixer connected to receive the second transmitting-filter-response and the second symbol, thereby generating a second weighted signal,
• a combiner in communication with at least the first mixer and the second mixer for generating a modulating quantity on the basis of at least the first weighted signal and the second weighted signal, and
• a phase modulator in communication with the combiner for modulating the phase component of the carrier signal on the basis of the modulating quantity, wherein the first symbol is modulated during a symbol start period that is adjacent to a symbol start period associated with the modulation of the second symbol.

A method for communicating symbols during consecutive symbol start periods to cause a temporal overlap of symbols during symbol transmission intervals, the method comprising,

• providing transmitting-filter responses,
• generating weighted signals by filtering the temporally overlapped symbols with respective transmitting-filter responses,
• accumulating the weighted signals based on the temporally overlapped symbols,
• transmitting a carrier signal having a phase component modulated by the accumulated signal,
• providing receiving-filter responses matched to the transmitting-filter responses,
• filtering a demodulated phase component of a received signal with the receiving-filter responses to generate a weighted output representative of the transmitting-filter responses, and,
• accumulating the weighted outputs during symbol transmission intervals to provide a signal representative of a transmitted symbol,
• where a symbol start period is at least one clock cycle.

A transmitter for encoding a first symbol and a second symbol on a phase component of a carrier signal, the first symbol being transmitted during a first symbol transmission interval, the second symbol being transmitted during a second symbol transmission interval overlapping the first symbol transmission interval, the transmitter comprising

• means for generating a first transmitting-filter-response in a first interval,
• means for generating a first weighted signal based on the first transmitting-filter-response and the first symbol,
• means for generating a second transmitting-filter response in a second interval overlapping the first interval,
• means to generate a second weighted signal based on the second transmitting-filter-response and the second symbol,
• means for generating a modulating quantity on the basis of at least the first weighted signal and the second weighted signal, and
• means for phase modulating the phase component of the carrier signal on the basis of the modulating quantity, wherein the first symbol is modulated during a symbol start period that is adjacent to a symbol start period associated with the modulation of the second symbol.

A receiver for extracting a selected symbol from a phase-modulated carrier having a phaseform representative of the selected symbol and at least two additional symbols having temporal overlap with the selected symbol, the selected symbol being transmitted during a selected-symbol transmission interval, the phaseform being generated by evaluating combination of transmitting-filter responses, the combination including a first element generated by weighting a selected transmitting-filter response by the selected symbol, the receiver comprising

• means for demodulating the phaseform from the phase-modulated carrier,
• means for generating a receiving-filter response corresponding to the selected transmitting-filter response wherein the receiving-filter response is produced by a wavelet function,
• means for filtering the phaseform with the receiving-filter response to generate a weighted output representative of the combination of transmitting-filter responses weighted by the receiving-filter response, and
• means for accumulating the weighted output over a symbol transmission interval, thereby generating a signal representative of the selected symbol, wherein the selected symbol is demodulated during a symbol start period that is adjacent to a symbol start period associated with the demodulation of at least one of the additional symbols.