A communication device according to an embodiment includes an oscillator, a first signal generation circuit, a first insulation element, a first receiving circuit, and a first output circuit. The oscillator is configured to output a first carrier signal when at least one of a plurality of input signals that are externally input is at a first logic level. The first carrier signal and a first input signal among the input signals are input to the first signal generation circuit. The first signal generation circuit is configured to generate a first signal when the first input signal changes from a second logic level to the first logic level, output a first modulated signal based on the first signal, and thereafter output a second modulated signal based on the first carrier signal.

Aspects of this disclosure relate to a very low intermediate frequency (VLIF) receiver with multi-decade contiguous radio frequency (RF) band coverage. Non-quadrature local oscillator (LO) signals drive mixers. The non-quadrature signals can be generated from low noise digital dividers having non-traditional division ratios. The non-traditional division ratios can be prime number ratios such as 5 and 7. The systematic non-quadrature nature of the LO/mixer can be subsequently corrected by a deterministic I-Q coupling network prior to complex signal processing.

An in-phase and quadrature mismatch compensator for a quadrature transmitter includes a delay element, a complex-valued filter and an adder. The delay element receives an input transmit signal and outputs a delayed transmit signal. The complex-valued filter receives the input transmit signal and outputs a selected part of a filtered output transmit signal. The adder adds the delayed transmit signal and the selected part of the filtered output transmit signal and outputs a pre-compensated transmit signal. In one embodiment, the selected part of the filtered output transmit signal includes the real part of the complex-valued output transmit signal. In another embodiment, the selected part of the filtered output transmit signal includes the imaginary part of the complex-valued output transmit signal. Two transmit real-valued compensators are also disclosed that combine the in-phase and quadrature signals before being filtered.

Described are methods for dealing with phase noise, e.g., common phase error and/or inter-carrier interference, in communication systems, and apparatuses for the same. A method can include at least: transmitting one or more reference signals (in-band signals within a channel); and mapping the reference signals to radio resources in the channel for transmission of the reference signals. An amount of the radio resources may depend on, e.g., information about a modulation and coding scheme used for transmission. An associated method can include at least: receiving one or more reference signals, and mapping the reference signals to radio resources in the channel for reception of the reference signals; receiving information about a modulation and coding scheme to be used, an amount of the radio resources depending on, e.g., information about the modulation and coding scheme used for reception; and using the reference signals to compensate for phase noise.

An electronic device and a method performed by an electronic device are provided. A number of frequency bands of a plurality of carriers to be used in a plurality of communication circuits for communication is determined. The plurality of communication circuits process carrier signals in different frequency bands. A switching operation, performed by at least one switch, is controlled based on the number of frequency bands and a specified condition that is based on frequency bands able to be processed by an LNA included in each of the plurality of communication circuits. The carrier signals of the plurality of carriers is processed using at least one communication circuit. The at least one switch is alternately connected to two communication circuits and is configured to provide a reception carrier signal from at least one antenna to one of the two communication circuits based on a switching operation.

A communication device according to an embodiment includes an oscillator, a first signal generation circuit, a first insulation element, a first receiving circuit, and a first output circuit. The oscillator is configured to output a first carrier signal when at least one of a plurality of input signals that are externally input is at a first logic level. The first carrier signal and a first input signal among the input signals are input to the first signal generation circuit. The first signal generation circuit is configured to generate a first signal when the first input signal changes from a second logic level to the first logic level, output a first modulated signal based on the first signal, and thereafter output a second modulated signal based on the first carrier signal.

[Object] To realize IQ imbalance correction in a more preferable aspect. [Solution] An information processing device including: a calculation unit configured to calculate an error between predetermined reference coordinates on an IQ plane and a signal point of a received predetermined reference signal on a basis of a reception result of the reference signal on which phase modulation or quadrature amplitude modulation is implemented and mapping information of the reference signal; and a generation unit configured to generate correction data for correcting a deviation of a signal point of a received signal on a basis of a calculation result of the error.

A radio frequency (RF) transceiver includes a reference signal source to generate a reference signal, a local RF source to generate a local RF signal and a mixed-signal phase/frequency detector to compare the reference signal to the local RF signal, and to generate a difference signal from the comparison, wherein the difference signal comprises a modulation component and an error component. The transceiver also includes a receiver front end to receive and downconverts an angle-modulated RF signal to a baseband signal, a quadrature modulator configured to angle-modulate the reference signal source with the baseband signal.

Quadrature error correction (QEC) for radio transceivers are provided herein. In certain embodiments, a transceiver includes an in-phase (I) signal path including a first controllable amplifier coupled to a first data converter, and a quadrature-phase (Q) signal path including a second controllable amplifier coupled to a second data converter. The transceiver further includes a QEC circuit operable to correct for a quadrature error between the I signal path and the Q signal path by adjusting a gain of the first controllable amplifier and/or a gain of the second controllable amplifier.

A method for communicating between a first radio frequency communications device including a first local oscillator and a second radio frequency communications device including a second local oscillator includes receiving a packet using a receiver of the first radio frequency communications device. The method includes detecting an average frequency offset based on sequential samples of the packet. The method includes applying a first adjustment to the first local oscillator to reduce a frequency offset between the first local oscillator and the second local oscillator. The first adjustment is based on the average frequency offset. The method includes, after adjusting the first local oscillator, transmitting a second packet to the second radio frequency communications device by the first radio frequency communications device using the first adjustment and the first local oscillator.