This envelope-detecting circuit comprises: a first multiplier able to multiply a first example of a signal received on an input port by itself, a modifier able to modify the amplitude of the power spectrum, of a second example of the signal received on the input port, at the frequency f.sub.c without modifying the amplitude of this power spectrum in a useful frequency band, a second multiplier able to multiply the modified signal by itself, a subtractor able to subtract from each other the signals delivered by the multipliers, a filter able to remove frequency components higher than or equal to 2f.sub.c in a signal obtained from the signal delivered by the subtractor, this filter being able to deliver the result of this filtering on an output connected to an output port of the envelope-detecting circuit.

This envelope-detecting circuit comprises: a first multiplier able to multiply a first example of a signal received on an input port by itself, a modifier able to modify the amplitude of the power spectrum, of a second example of the signal received on the input port, at the frequency f.sub.c without modifying the amplitude of this power spectrum in a useful frequency band, a second multiplier able to multiply the modified signal by itself, a subtractor able to subtract from each other the signals delivered by the multipliers, a filter able to remove frequency components higher than or equal to 2f.sub.c in a signal obtained from the signal delivered by the subtractor, this filter being able to deliver the result of this filtering on an output connected to an output port of the envelope-detecting circuit.

A receiver includes one or more mixers configured to sample an input analog signal at a plurality of discrete points in time to obtain a discrete-time sampled signal based on a local oscillating signal provided by a local oscillator; and a sample reordering circuit coupled to the one or more mixers and configured to reorder a sequence of samples received from the one or more mixers.

According to one embodiment, a wireless communication apparatus includes receiver circuitry and transmitter circuitry. The receiver circuitry is configured to receive a first frame addressed to another apparatus, the first frame being transmitted by a first wireless communication apparatus, and estimate a difference between an oscillation frequency of an oscillator of the first wireless communication apparatus and an oscillation frequency of an oscillator of the wireless communication apparatus based on the first frame. The transmitter circuitry is configured to transmit a third frame at a frequency determined based on the difference during a period at least partially overlapping a period during which the first wireless communication apparatus transmits a second frame addressed to a second wireless communication apparatus.

According to one embodiment, a wireless communication apparatus includes receiver circuitry and transmitter circuitry. The receiver circuitry is configured to receive a first frame addressed to another apparatus, the first frame being transmitted by a first wireless communication apparatus, and estimate a difference between an oscillation frequency of an oscillator of the first wireless communication apparatus and an oscillation frequency of an oscillator of the wireless communication apparatus based on the first frame. The transmitter circuitry is configured to transmit a third frame at a frequency determined based on the difference during a period at least partially overlapping a period during which the first wireless communication apparatus transmits a second frame addressed to a second wireless communication apparatus.

A radio receiver includes a local oscillator arrangement and a controller. The local oscillator arrangement is arranged to provide a signal for down-conversion of radio frequency signal to an intermediate frequency or a baseband frequency in the radio receiver, and the local oscillator arrangement is capable of selectably providing multiple frequency generation qualities. The controller is arranged to estimate a tolerable frequency generation quality for the current operation of the radio receiver or determine whether the current operation of the radio receiver is satisfactory in sense of a currently provided frequency generation quality, and based on the estimation or determination adjust frequency generation quality of the local oscillator arrangement by selecting one of the multiple frequency generation qualities. A radio arrangement, a method and a computer program are also disclosed.

A radio receiver includes a local oscillator arrangement and a controller. The local oscillator arrangement is arranged to provide a signal for down-conversion of radio frequency signal to an intermediate frequency or a baseband frequency in the radio receiver, and the local oscillator arrangement is capable of selectably providing multiple frequency generation qualities. The controller is arranged to estimate a tolerable frequency generation quality for the current operation of the radio receiver or determine whether the current operation of the radio receiver is satisfactory in sense of a currently provided frequency generation quality, and based on the estimation or determination adjust frequency generation quality of the local oscillator arrangement by selecting one of the multiple frequency generation qualities. A radio arrangement, a method and a computer program are also disclosed.

The disclosure relates to technology for shifting a frequency range of a signal. In one aspect, a circuit comprises a frequency mixer, a frequency synthesizer configured to generate an oscillator signal, a programmable driver, and a controller. The programmable driver is configured to receive the oscillator signal from the frequency synthesizer and to provide the oscillator signal to the oscillator input of the frequency mixer. The programmable driver is configured to have a variable drive strength. The controller is configured to control the drive strength of the programmable driver based on a frequency of the oscillator signal to adjust a rise time and a fall time of the oscillator signal at the oscillator input of the frequency mixer.

The disclosure relates to technology for shifting a frequency range of a signal. In one aspect, a circuit comprises a frequency mixer, a frequency synthesizer configured to generate an oscillator signal, a programmable driver, and a controller. The programmable driver is configured to receive the oscillator signal from the frequency synthesizer and to provide the oscillator signal to the oscillator input of the frequency mixer. The programmable driver is configured to have a variable drive strength. The controller is configured to control the drive strength of the programmable driver based on a frequency of the oscillator signal to adjust a rise time and a fall time of the oscillator signal at the oscillator input of the frequency mixer.

Techniques are disclosed relating to DC interference cancelation in received wireless signals. Disclosed techniques may be performed in the digital domain, in conjunction with analog cancelation techniques. In some embodiments, a receiver apparatus operates a local oscillator at a frequency corresponding to a particular pilot symbol in a received wireless signal. In some embodiments the receiver estimates DC interference at the frequency based on the received pilot symbol (this may be facilitated by the fact that the contents of pilot symbols are known, because they are typically used for channel estimation). In some embodiments, the receiver apparatus is configured to cancel the DC interference based on the estimate to determine received data in subsequently received signals at the frequency. Disclosed techniques may allow narrowband receivers to efficiently use more of their allocated frequency bandwidth, rather than wasting bandwidth near the frequency of the local oscillator.