A frequency shift keying (FSK) demodulator for demodulating symbols includes correlation circuits configured to output correlation metrics based on a buffered portion of an input signal as the input signal is continuously received by the FSK demodulator. The FSK demodulator also includes a result combining stage configured to output a set of first correlation results based on correlation metrics generated for a first portion of the input signal encoding a current symbol and at least one past symbol, and a set of second correlation results based on correlation metrics generated for a second portion of the input signal encoding the current symbol and at least one next symbol; and a time combining stage configured to combine a set of delayed first correlation results with the set of second correlation results to produce a demodulation decision that returns a most likely symbol value for the current symbol.

The communication process for high-sensitivity and synchronous demodulation signals between a transmitter (2) and a receiver (3) comprises a first synchronisation phase followed by a modulation and demodulation phase of the data. To achieve this, the transmitter transmits a pseudo-periodic chirp signal to the receiver, where a frequency conversion of the chirp signal is performed in a mixer (33) by an oscillating signal (So) at constant frequency of a local oscillator (34) to supply an intermediate signal, which is filtered and sampled for a logic unit (37). An assembly (38) of m pairs DFT blocks phase-shifted in relation to one another and operating in parallel is provided in the logic unit. A processing unit (39) receives the result of the pairs of the assembly to determine frequency and phase errors between the transmitter and the receiver on the basis of two peaks detected by one of the pairs above a threshold to synchronise the receiver.

A method of transmitting a Physical Layer Convergence Procedure (PLCP) frame in a Very High Throughput (VHT) Wireless Local Area Network (WLAN) system includes generating a MAC Protocol Data Unit (MPDU) to be transmitted to a destination station (STA), generating a PLCP Protocol Data Unit (PPDU) by adding a PLCP header, including an L-SIG field containing control information for a legacy STA and a VHT-SIG field containing control information for a VHT STA, to the MPDU, and transmitting the PPDU to the destination STA. A constellation applied to some of Orthogonal Frequency Division Multiplex (OFDM) symbols of the VHT-SIG field is obtained by rotating a constellation applied to an OFDM symbol of the L-SIG field.

Methods, systems and device for achieving synchronization in an orthogonal time frequency space (OTFS) signal receiver are described. An exemplary signal reception technique includes receiving an OTFS modulated wireless signal comprising pilot signal transmissions interspersed with data transmissions, calculating autocorrelation of the wireless signal using the wireless signal and a delayed version of the wireless signal that is delayed by a pre-determined delay, thereby generating an autocorrelation output, processing the autocorrelation filter through a moving average filter to produce a fine timing signal. Another exemplary signal reception technique includes receiving an OTFS modulated wireless signal comprising pilot signal transmissions interspersed with data transmissions, performing an initial automatic gain correction of the received OTFS wireless signal by peak detection and using clipping information, performing coarse automatic gain correction on results of a received and initial automatic gain control (AGC)-corrected signal.

A communication signal demodulation apparatus demodulates a communication signal to generate an output signal. The communication signal demodulation apparatus includes: plural sensor circuits which sense different electrical characteristics of one same communication signal and generate corresponding sensing modulation signals respectively; plural processing filters which filter the corresponding sensing modulation signals respectively and generate corresponding filtered modulation signals respectively; plural demodulators which demodulate the plural filtered modulation signals and generate corresponding demodulation signals respectively, wherein each of the filtered modulation signals corresponds to at least one of the demodulators; and a determination circuit which receive the plural demodulation signals, determine whether each unit signal of each of the demodulation signals is correct or not according to a determination mechanism, and combine one or more correct unit signals to generate the output signal.

A communication signal demodulation apparatus demodulates a communication signal to generate an output signal. The communication signal demodulation apparatus includes: plural sensor circuits which sense different electrical characteristics of one same communication signal and generate corresponding sensing modulation signals respectively; plural processing filters which filter the corresponding sensing modulation signals respectively and generate corresponding filtered modulation signals respectively; plural demodulators which demodulate the plural filtered modulation signals and generate corresponding demodulation signals respectively, wherein each of the filtered modulation signals corresponds to at least one of the demodulators; and a determination circuit which receive the plural demodulation signals, determine whether each unit signal of each of the demodulation signals is correct or not according to a determination mechanism, and combine one or more correct unit signals to generate the output signal.

A method and apparatus for synchronizing a wireless communication receiver such as a Bluetooth receiver, including estimating the condition of the communication channel and operating the receiver either in frequency domain mode or in time domain mode based on the channel condition estimation. A soft threshold is used to estimate the symbols of the access address code. Oversampled data rate received data is processed at symbol rate of the data. Receiver functions are terminated upon determining that no signal that the receiver can decode is being received. Synchronization includes a correlator that processes an entire address code or a correlator that processes the address code in segments.

A method and apparatus for synchronizing a wireless communication receiver such as a Bluetooth receiver, including estimating the condition of the communication channel and operating the receiver either in frequency domain mode or in time domain mode based on the channel condition estimation. A soft threshold is used to estimate the symbols of the access address code. Oversampled data rate received data is processed at symbol rate of the data. Receiver functions are terminated upon determining that no signal that the receiver can decode is being received. Synchronization includes a correlator that processes an entire address code or a correlator that processes the address code in segments.

A data transmission method includes obtaining a data stream. The data stream includes a plurality of bit groups. The method also includes modulating the data stream into a modulated symbol stream according to a modulation rule, and generating a modulated signal based on the modulated symbol stream. The modulated symbol stream includes a plurality of modulated symbol. The modulation rule includes determining, in a symbol period of one modulated symbol based on a value of a first bit group, a zero time point corresponding to the first bit group. The zero time point is a zero crossing point of the modulated signal in the symbol period. The first bit group includes at least one bit. The first bit group is one of the plurality of bit groups. The method further includes sending the modulated signal.

Methods, systems and device for achieving synchronization in an orthogonal time frequency space (OTFS) signal receiver are described. An exemplary signal reception technique includes receiving an OTFS modulated wireless signal comprising pilot signal transmissions interspersed with data transmissions, calculating autocorrelation of the wireless signal using the wireless signal and a delayed version of the wireless signal that is delayed by a pre-determined delay, thereby generating an autocorrelation output, processing the autocorrelation filter through a moving average filter to produce a fine timing signal. Another exemplary signal reception technique includes receiving an OTFS modulated wireless signal comprising pilot signal transmissions interspersed with data transmissions, performing an initial automatic gain correction of the received OTFS wireless signal by peak detection and using clipping information, performing coarse automatic gain correction on results of a received and initial automatic gain control (AGC)-corrected signal.