A phase noise suppression method for a multiple-input multiple-output (MIMO) system with a plurality of co-reference channels includes: dividing the phase noise of each channel in the MIMO system into common phase noise and independent phase noise, and constructing a certain number of joint phase states for the independent phase noise; inserting a pilot sequence into the sent signal based on a preset cycle, obtaining the common phase noise based on the pilot at receiver, and performing compensation; and performing signal demodulation on each joint state of the independent phase noise, and comparing the posterior log likelihood values to select the optimal result to output. The above method can significantly improve the phase noise suppression performance of the MIMO system with a plurality of co-reference channels, thereby providing support for improving the system capacity by using MIMO technology.

A radio frequency (RF) receiver has an antenna, a low-noise amplifier, a sigma-delta frequency synthesizer/voltage-controlled oscillator (VCO), an in-phase and quadrature (I/Q) mixer, a channel filter, and a digital baseband circuit. The digital baseband circuit has a demodulator, a preamble detection and carrier frequency offset (CFO) estimation circuit, and a CFO to sigma-delta modulation (SDM) input mapper. A preamble field of a digital demodulated signal generated by the demodulator is detected by the preamble detection and CFO estimation circuit. The RF receiver simultaneously compensates its CFO and optimizes a bandwidth of the channel filter based on the detection of the preamble field of the digital demodulated signal by the preamble detection and CFO estimation circuit.

Disclosed are an airborne electromagnetic wave device, and an anti-interference system, method and apparatus. The anti-interference method comprises: detecting an interference source, and obtaining a working frequency and a bandwidth of the interference source; calculating an interfered bandwidth range at least on the basis of the working frequency and bandwidth of the interference source; and controlling an electrically tunable filter provided in a transmission channel of the airborne electromagnetic wave device to filter signals within the interfered bandwidth range. Hence, the interfered airborne electromagnetic wave device is triggered to control the electrically tunable filter to filter the signals within the interfered bandwidth range, so that the interfered airborne electromagnetic wave device suspends signal transmission within the interfered bandwidth range, so that communication interference among different satellite communication systems is eliminated; moreover, the electrically tunable filter is provided on the transmission channel of the interfered airborne electromagnetic wave device, so that the present invention can be widely applied to multiple different airborne electromagnetic wave devices and has relatively wide applicability.

Disclosed are an airborne electromagnetic wave device, and an anti-interference system, method and apparatus. The anti-interference method comprises: detecting an interference source, and obtaining a working frequency and a bandwidth of the interference source; calculating an interfered bandwidth range at least on the basis of the working frequency and bandwidth of the interference source; and controlling an electrically tunable filter provided in a transmission channel of the airborne electromagnetic wave device to filter signals within the interfered bandwidth range. Hence, the interfered airborne electromagnetic wave device is triggered to control the electrically tunable filter to filter the signals within the interfered bandwidth range, so that the interfered airborne electromagnetic wave device suspends signal transmission within the interfered bandwidth range, so that communication interference among different satellite communication systems is eliminated; moreover, the electrically tunable filter is provided on the transmission channel of the interfered airborne electromagnetic wave device, so that the present invention can be widely applied to multiple different airborne electromagnetic wave devices and has relatively wide applicability.

Methods, systems, and devices for wireless communications are described. A transmitting (Tx) device transmits, to a receiving (Rx) device, a control message indicating a location of one or more noise spurs associated with wireless communications performed by the Tx device using a set of resources, where the location includes a frequency location of the one or more noise spurs in the frequency domain. The Tx device then generates a data message to be communicated using the set of resources associated with the one or more noise spurs based on transmitting the control message, and transmits the generated data message to the Rx device using the set of resources associated with the one or more noise spurs. By indicating the location of the noise spurs, the Rx device may be more able to more efficiently identify and address (e.g., filter out, ignore) the noise spurs within the data message.

Methods, systems, and devices for wireless communications are described. A transmitting (Tx) device transmits, to a receiving (Rx) device, a control message indicating a location of one or more noise spurs associated with wireless communications performed by the Tx device using a set of resources, where the location includes a frequency location of the one or more noise spurs in the frequency domain. The Tx device then generates a data message to be communicated using the set of resources associated with the one or more noise spurs based on transmitting the control message, and transmits the generated data message to the Rx device using the set of resources associated with the one or more noise spurs. By indicating the location of the noise spurs, the Rx device may be more able to more efficiently identify and address (e.g., filter out, ignore) the noise spurs within the data message.

Circuits and methods that provide fine-resolution measurements of RF signal power within a communication system band, thereby more accurately measuring RF interference or the potential of RF interference. One aspect of embodiments of the present invention is a narrow-band tunable filter that includes two elements coupled in series, a periodic passband filter and a tunable filter. The purpose of the periodic passband filter is to generate multiple periodic passbands for an applied RF signal. The purpose of the tunable filter is to generate a single passband, generally with a tunable center frequency. By serially coupling the two filter types in either order, the single passband of the tunable filter is superimposed over one of the periodic passbands of the periodic passband filter, synergistically resulting in an extremely narrow passband.

Circuits and methods that provide fine-resolution measurements of RF signal power within a communication system band, thereby more accurately measuring RF interference or the potential of RF interference. One aspect of embodiments of the present invention is a narrow-band tunable filter that includes two elements coupled in series, a periodic passband filter and a tunable filter. The purpose of the periodic passband filter is to generate multiple periodic passbands for an applied RF signal. The purpose of the tunable filter is to generate a single passband, generally with a tunable center frequency. By serially coupling the two filter types in either order, the single passband of the tunable filter is superimposed over one of the periodic passbands of the periodic passband filter, synergistically resulting in an extremely narrow passband.

Circuits for a receiver, comprising: M first mixers that each receive an input signal, that are each clocked by a different phase of a first common clock frequency, and that each provide an output, wherein M is a count of the first mixers; and M sets of N second mixers, wherein N is a count of the second mixers in each of the M sets, wherein each second mixer in each set of N second mixers receives as an input the output of a corresponding one of the M first mixers, wherein each of the N second mixers in each of the M sets are clocked by a different phase of a second common clock frequency, and wherein each of the second mixers has an output.

Circuits for a receiver, comprising: M first mixers that each receive an input signal, that are each clocked by a different phase of a first common clock frequency, and that each provide an output, wherein M is a count of the first mixers; and M sets of N second mixers, wherein N is a count of the second mixers in each of the M sets, wherein each second mixer in each set of N second mixers receives as an input the output of a corresponding one of the M first mixers, wherein each of the N second mixers in each of the M sets are clocked by a different phase of a second common clock frequency, and wherein each of the second mixers has an output.