A single channel receiver includes an input terminal that receives an analog input signal, a mixer that down-mixes the analog input signal by use of a phase- and/or frequency-corrected oscillator frequency signal and shifts complex-valued information contained in the analog input signal to the real part (or alternatively to the imaginary part) to obtain an intermediate real-valued analog signal, an analog-to-digital-converter that converts the intermediate analog signal into an intermediate digital signal, a demodulator that demodulates the intermediate digital signal into a digital output signal, a phase tracking loop that detects zero-crossings in the intermediate digital signal to obtain phase error information representing a phase error in the intermediate digital signal, and an oscillator that generates the phase- and/or frequency-corrected oscillator frequency signal by compensating the phase and/or frequency error in the intermediate digital signal by correcting the phase of the oscillator frequency signal with the phase error information.

A digital receiver being adapted for receiving an MSK modulated signal, comprises a digital front-end unit (10) adapted for providing samples having a phase value (θ.sub.measure) of a down-mixed signal, a phase compensation unit (11) adapted for compensating the phase value (θ.sub.measure) by delivering a phase offset compensated sample having a phase value (θ.sub.sync), and a coherent demodulator (12) adapted for recovering information content from the phase offset compensated sample. The phase compensation unit (11) is adapted for analyzing a phase value (θ.sub.sync) of the phase offset compensated sample, calculating a phase offset value (θ.sub.offset) based on the phase value (θ.sub.sync) of the phase offset compensated sample, and applying the phase offset value (θ.sub.offset) when delivering a subsequent phase offset compensated sample.

Circuits, methods, and apparatus that provide improved data recovery for data transmitted through a channel of limited bandwidth. An example can provide circuits, methods, and apparatus that can equalize losses in a physical channel. This equalization can provide an overall channel response that is more consistent and uniform.

A method for decoding an RF signal bearing a sequence of transmitted symbols modulated by CPM. The method includes, at the receiver: estimating model parameters {h, ω, Φ.sub.0} among which h characterizes a modulation index, ω characterizes a carrier frequency offset and Φ.sub.0 characterizes an initial phase offset, and detecting received symbols corresponding to said transmitted symbols of the sequence, wherein, at time nT where T is a symbol duration, the parameters {h, ω, Φ.sub.0} are estimated by solving a system of three linear equations whose: three unknowns {ĥ.sup.(n), {circumflex over (ω)}.sup.(n), {circumflex over (Φ)}.sub.0.sup.(n)} are respectively function of said model parameters {h, ω, Φ.sub.0}, and coefficients {B.sup.(n), C.sup.(n), D.sup.(n), F.sup.(n), G.sup.(n), H.sup.(n), v.sub.1.sup.(n), v.sub.2.sup.(n), v.sub.3.sup.(n)} are computed in a recursive way in function of: a sequence of symbols {â.sub.n} corresponding to the sequence of transmitted symbols up to time nT, and measured phases {Ψ.sub.k} of samples {y.sub.k} of the RF signal received from time (n−1)T to time nT.

A radio transmission method which includes a steps of simulation of a phase modulation of a radio carrier by the successive transmission of a carrier of a main frequency f and of a carrier of an offset frequency f+Δf, the offset frequency having a frequency difference suitable for simulating a given phase shift of the main frequency at the end of a given time T. The invention further relates to a radio transmission device for implementing the method which includes a radio integrated circuit for generating programmable frequency modulation, means for programming, in this radio integrated circuit, the main frequency f and the offset frequency f+Δf and means for driving this radio integrated circuit in order to generate the frequencies as a function of the signal to be transmitted.

In an embodiment, a receiver detects a timing error between a transmitter clock at a transmitter and a receiver clock at a receiver associated with an exchange of CPM signals. The receiver phase aligns input samples of a candidate received signal over a time window based on a rotating signal corresponding to a phase progression of the candidate received signal. The receiver generates first and second partial sums of the phase-aligned input samples that are accumulations of phase-aligned input samples corresponding to modulation symbols that contribute positive and negative phases, respectively, to the phase progression. The receiver determines a phase difference between the first and second partial sums, and generates a timing-error metric that is indicative of a timing error between the transmitter clock and the receiver clock based at least in part upon the determined phase difference.

A DARC signal demodulation circuit assemblage for recovering a DARC signal (DARC data) from an FM multiplex transmission signal includes: a pilot tone regulation circuit to obtain first and second mutually orthogonal oscillation synchronous with a stereo pilot tone encompassed by the FM multiplex transmission signal; a frequency quadruplication section for obtaining third and fourth mutually orthogonal oscillation having a frequency quadrupled as to the stereo pilot tone; a first multiplication section for obtaining a first multiplication signal from the FM multiplex transmission signal and from the third oscillation; a second multiplication section for obtaining a second multiplication signal from the FM multiplex transmission signal and from the fourth oscillation; first/second low-pass filters for obtaining first/second DARC signal components by low-pass filtration of the first and second multiplication signals; and an FM demodulation section for obtaining the DARC signal from a frequency demodulation of the first/second DARC signal components.

A single channel receiver includes an input terminal that receives an analog input signal, a mixer that down-mixes the analog input signal by use of a phase- and/or frequency-corrected oscillator frequency signal and shifts complex-valued information contained in the analog input signal to the real part (or alternatively to the imaginary part) to obtain an intermediate real-valued analog signal, an analog-to-digital-converter that converts the intermediate analog signal into an intermediate digital signal, a demodulator that demodulates the intermediate digital signal into a digital output signal, a phase tracking loop that detects zero-crossings in the intermediate digital signal to obtain phase error information representing a phase error in the intermediate digital signal, and an oscillator that generates the phase- and/or frequency-corrected oscillator frequency signal by compensating the phase and/or frequency error in the intermediate digital signal by correcting the phase of the oscillator frequency signal with the phase error information.

A structure for generating sequences. The structure includes a binary shift register; a feedback structure connected to the shift register arranged to define a linear feedback shift register according to a polynomial; a first output arranged to collect one or more state values from a first group of elements of the shift register, the one or more state values from the first group forming a value of a first sequence; and a second output arranged to collect one or more state values from a second group of elements of the shift register, the one or more state values from the second group forming a value of a second sequence. No element of the second group belongs to the first group.

Circuits, methods, and apparatus that provide improved data recovery for data transmitted through a channel of limited bandwidth. An example can provide circuits, methods, and apparatus that can equalize losses in a physical channel. This equalization can provide an overall channel response that is more consistent and uniform.