The invention discloses a modulator, a demodulator and a wireless communication system. The wireless communication system comprises a modulator and a demodulator. The modulator is suitable for generating a target linear frequency modulation signal, wherein the target linear frequency modulation signal is a signal of which the frequency is varied linearly over time, wherein the phase of the target linear frequency modulation signal is determined by an initial frequency and a frequency stepping of the target linear frequency modulation signal, and the frequency stepping is determined by the bandwidth of the target linear frequency modulation signal and the spreading factor of the target linear frequency modulation signal. The demodulator is suitable for demodulating the target linear frequency modulation signal. According to the scheme, power consumption can be reduced while long-distance signal transmission is realized.

A method of generating and processing an analog transport signal for a fronthaul of a radio access network, where the analog signal carries a plurality of channels. The analog signal is generated by defining frequency bands of a fixed width within the analog transport signal. Channels are arranged within each frequency band so that, if the analog transport signal is sampled at a frequency equal to twice the fixed width, each channel of a frequency band has the same intermediate frequency as a corresponding channel of at least one other frequency band. A method of demultiplexing the analog transport signal for execution by a receiver is also proposed.

A method of generating and processing an analog transport signal for a fronthaul of a radio access network, where the analog signal carries a plurality of channels. The analog signal is generated by defining frequency bands of a fixed width within the analog transport signal. Channels are arranged within each frequency band so that, if the analog transport signal is sampled at a frequency equal to twice the fixed width, each channel of a frequency band has the same intermediate frequency as a corresponding channel of at least one other frequency band. A method of demultiplexing the analog transport signal for execution by a receiver is also proposed.

One example wireless communication method includes transforming an information signal to a discrete sequence, where the discrete sequence is a Zak transformed version of the information signal, generating a first ambiguity function corresponding to the discrete sequence, generating a second ambiguity function by pulse shaping the first ambiguity function, generating a waveform corresponding to the second ambiguity function, and transmitting the waveform over a wireless communication channel. Another communication method includes transforming an information signal to a discrete lattice domain signal, shaping bandwidth and duration of the discrete lattice domain signal by a two-dimensional filtering procedure to generate a filtered information signal, generating, using a Zak transform, a time domain signal from the filtered information signal, and transmitting the time domain signal over a wireless communication channel.

One example wireless communication method includes transforming an information signal to a discrete sequence, where the discrete sequence is a Zak transformed version of the information signal, generating a first ambiguity function corresponding to the discrete sequence, generating a second ambiguity function by pulse shaping the first ambiguity function, generating a waveform corresponding to the second ambiguity function, and transmitting the waveform over a wireless communication channel. Another communication method includes transforming an information signal to a discrete lattice domain signal, shaping bandwidth and duration of the discrete lattice domain signal by a two-dimensional filtering procedure to generate a filtered information signal, generating, using a Zak transform, a time domain signal from the filtered information signal, and transmitting the time domain signal over a wireless communication channel.

A digital radio receiver has a matched filter bank of filter modules for receiving phase- or frequency-modulated radio signals. Each module cross-correlates a sampled signal with a respective multi-symbol filter sequence, using a plurality of samples in each symbol period. The matched filter bank calculates first values (z.sub.n(1)), for respective symbol periods, of a cross-correlation of the sampled signal with a first complex exponential function defined at sample points over one symbol period, and calculates second values (z.sub.n(−1)), for the respective symbol periods, of a cross-correlation of the sampled signal with a second, different, complex exponential function. A set of the filter modules cross-correlates the sampled signal with their respective filter sequences using an algorithm that takes, as input, the first values (z.sub.n(1)) for symbol periods at which the respective filter sequence has a first value, and the second values (z.sub.n(−1)) for symbol periods at which the filter sequence has a second, different, value.

A digital radio receiver has a matched filter bank of filter modules for receiving phase- or frequency-modulated radio signals. Each module cross-correlates a sampled signal with a respective multi-symbol filter sequence, using a plurality of samples in each symbol period. The matched filter bank calculates first values (z.sub.n(1)), for respective symbol periods, of a cross-correlation of the sampled signal with a first complex exponential function defined at sample points over one symbol period, and calculates second values (z.sub.n(−1)), for the respective symbol periods, of a cross-correlation of the sampled signal with a second, different, complex exponential function. A set of the filter modules cross-correlates the sampled signal with their respective filter sequences using an algorithm that takes, as input, the first values (z.sub.n(1)) for symbol periods at which the respective filter sequence has a first value, and the second values (z.sub.n(−1)) for symbol periods at which the filter sequence has a second, different, value.

A method of compensating for IQ mismatch (IQMM) in a transceiver may include sending first and second signals from a transmit path through a loopback path, using a phase shifter to introduce a phase shift in at least one of the first and second signals, to obtain first and second signals received by a receive path, using the first and second signals received by the receive path to obtain joint estimates of transmit and receive IQMM, at least in part, by estimating the phase shift, and compensating for IQMM using the estimates of IQMM. Using the first and second signals received by the receive path to obtain estimates of the IQMM may include processing the first and second signals received by the receive path as a function of one or more frequency-dependent IQMM parameters.

A method of compensating for IQ mismatch (IQMM) in a transceiver may include sending first and second signals from a transmit path through a loopback path, using a phase shifter to introduce a phase shift in at least one of the first and second signals, to obtain first and second signals received by a receive path, using the first and second signals received by the receive path to obtain joint estimates of transmit and receive IQMM, at least in part, by estimating the phase shift, and compensating for IQMM using the estimates of IQMM. Using the first and second signals received by the receive path to obtain estimates of the IQMM may include processing the first and second signals received by the receive path as a function of one or more frequency-dependent IQMM parameters.

A Bluetooth receiver is provided. The Bluetooth receiver comprises processing circuitry configured to receive a receive signal and to determine receive symbols based on the receive signal. The Bluetooth receiver further comprises control circuitry configured to determine a frequency offset and/or a modulation index of the receive signal based on the receive signal. The control circuitry is additionally configured to control an operation mode of the processing circuitry based on the determined frequency offset and/or the modulation index of the receive signal.