A polar transmitter including a digital power amplifier cell that includes a first circuit and an amplifier circuit. The first circuit is configured to receive a phase modulated carrier signal and to generate a PMOS control signal and an NMOS control signal such that the PMOS control signal and the NMOS control signal have different duty cycles. The amplifier circuit is configured to receive the PMOS control signal at a PMOS transistor and the NMOS control signal at an NMOS transistor. The first circuit is configured to align the PMOS control signal and the NMOS control signal with respect to one another such that a time that the NMOS transistor and the PMOS transistor of the amplifier circuit are simultaneously conducting is minimized. The amplifier circuit is configured to generate an amplified modulated carrier signal in response to the PMOS and NMOS control signals.

A system for automatically detecting the PHY mode based on the incoming preamble is disclosed. The system includes a multimode demodulator, which includes a preamble detector and a demodulator. The preamble detector is used to determine when the preamble has been received and the PHY mode being used by the sending node. An indication of the PHY mode is supplied to the demodulator, which then decides the incoming bit stream in accordance with the detected PHY mode. In some embodiments, one demodulator, capable of decoding the bit stream in accordance with a plurality of PHY modes is employed. In other embodiments, the system includes a plurality of demodulators, where each is dedicated to one PHY mode.

A method of recovering information encoded by a modulated sinusoidal waveform having first, second, third and fourth data notches at respective phase angles, where a power of the modulated sinusoidal waveform is reduced relative to a power of an unmodulated sinusoidal waveform within selected ones of the first, second, third and fourth data notches so as to encode input digital data. The method includes receiving the modulated sinusoidal waveform and generating digital values representing the modulated sinusoidal waveform. A digital representation of the unmodulated sinusoidal waveform is subtracted from the digital values in order to generate a received digital data sequence, which includes digital data notch values representative of the amplitude of the modulated sinusoidal waveform within the first, second, third and fourth data notches. The input digital data is then estimated based upon the digital data notch values.

A system and method for waveform modulation includes encoding input digital data at selected phase angles of an unmodulated sinusoidal waveform. The encoding includes selectively reducing a power of the unmodulated sinusoidal waveform at the selected phase angles in accordance with bit values of the input digital data so as to respectively define first, second, third and fourth data notches in the modulated sinusoidal waveform. An encoded analog waveform is then generated from a digital representation of the modulated sinusoidal waveform. The encoding is performed so that energies associated with the first and third data notches are balanced and energies associated with second and fourth data notches are also balanced. Each of the energies corresponds to a cumulative power difference between a power of the unmodulated sinusoidal waveform and a power of the modulated sinusoidal waveform over a phase angle range subtended by one of the data notches.

The present invention relates to communication technologies and provides a method and a device for FSK/GFSK demodulation, the method comprises: determining a digital information vector group {V.sub.l(i)} of a codeword a[k] to be demodulated and a corresponding phase matching vector group {.sub.i(i)} within the duration of (2M+1)T; determining a received phase vector {tilde over ()}(i) of a received FSK/GFSK baseband signal (t,a); determining an average phase difference .sub.l between {tilde over ()}(i) and .sub.l(i); calculating the phase matching degree Q.sub.l between {tilde over ()}(i) and .sub.l(i) after removing the impact of the average phase difference .sub.l, and determining an l value corresponding to the phase matching degree Q.sub.l being the maximum; and determining the a[k], corresponding to the l value, in the digital information vector V.sub.i(i) as a demodulation result. Because the impact of the average phase difference is removed during phase matching, the accuracy of phase matching is increased, and the performance of the phase domain demodulation technology is improved.

A system and method for narrowband sinewave modulation. The system includes an input buffer for storing input digital data and a sub-periodic modulator for encoding the input digital data in a periodic waveform. The sub-periodic modulator encodes one or more bit values of the input digital data within each period of the periodic waveform. One or more digital-to-analog converters generate an encoded analog waveform from a digital representation of the periodic waveform wherein the encoded analog waveform is of a frequency f and a power P. The encoding is performed by the sub-periodic modulator such that any signal of frequency f resulting from the encoding is of a power P at least 50 dB less than power P, where f is offset from f by more than 25 Hz.

A transmitter in a first wireless communication device and method therein are disclosed. The transmitter comprises a modulator and a rate selector configured to select a data rate. The rate selector comprises an input configured to receive input bits and an output to provide the bits with the selected data rate. The transmitter further comprises a bit to symbol mapper configured to receive the bits from the rate selector and map the bits to symbols of an arbitrary alphabet. The transmitter further comprises a spreading unit configured to spread the symbols received from the bit to symbol mapper to a chip sequence by means of a spreading code. The transmitter further comprises a re-mapping unit configured to map the chip sequence received from the spreading unit to produce signals for providing to the modulator.

Demodulating a modulated signal. A method may include receiving a modulated signal, wherein the modulated signal is a signal modulated according to a modulation function varying faster than the signal. The modulation function is a function of the signal. The modulated signal received is demodulated with an artificial neural network system, or ANN system, which is trained to identify bit values from signal patterns as caused by the modulation function, by identifying bit values from patterns of the modulated signal received. Related modulation and demodulation systems are disclosed.

A polar transmitter including a digital power amplifier cell that includes a first circuit and an amplifier circuit. The first circuit is configured to receive a phase modulated carrier signal and to generate a PMOS control signal and an NMOS control signal such that the PMOS control signal and the NMOS control signal have different duty cycles. The amplifier circuit is configured to receive the PMOS control signal at a PMOS transistor and the NMOS control signal at an NMOS transistor. The first circuit is configured to align the PMOS control signal and the NMOS control signal with respect to one another such that a time that the NMOS transistor and the PMOS transistor of the amplifier circuit are simultaneously conducting is minimized. The amplifier circuit is configured to generate an amplified modulated carrier signal in response to the PMOS and NMOS control signals.

Demodulating a modulated signal. A method may include receiving a modulated signal, wherein the modulated signal is a signal modulated according to a modulation function varying faster than the signal. The modulation function is a function of the signal. The modulated signal received is demodulated with an artificial neural network system, or ANN system, which is trained to identify bit values from signal patterns as caused by the modulation function, by identifying bit values from patterns of the modulated signal received. Related modulation and demodulation systems are disclosed.