A method of operating a communications system includes receiving a signal at a digital predistorter (DPD), introducing predistortion to the signal using the DPD, and converting the predistorted signal to an analog signal using a digital-to-analog converter having a first bandwidth. The method also includes amplifying the analog signal, sampling the amplified signal using an analog-to-digital converter having a second bandwidth less than the first bandwidth, and extracting coefficients of the DPD from the sampled signal.

Embodiments of the present disclosure provide an estimation apparatus and compensation apparatus for clipping distortion of multicarrier signals and a receiver. The estimation apparatus includes: a first calculating unit configured to multiply an error signal of each subcarrier in all or part of subcarriers in received multicarrier signals by a conjugation of an error signal of a subcarrier neighboring or spaced apart from each subcarrier; a second calculating unit configured to calculate an average value of all results of multiplication; a third calculating unit configured to calculate parameters of the clipping distortion of the multicarrier signals according to the average value; and an estimating unit configured to estimate the clipping distortion of the multicarrier signals according to the calculated parameters of the clipping distortion. By calculating the parameters of the clipping distortion of the multicarrier signals according to the error signals of the subcarriers, the clipping distortion of the multicarrier signals may be accurately estimated and compensated, with the method of calculation being simple and the bit error rate being low.

A method and apparatus for compensating for nonlinearities in a non-linear device for manipulating a signal is described. Shortly before an initial discrete power increase is applied to the device, a first pre-distortion function is generated on the basis of a first set of DPD parameters and applied to the signal before it reaches the device. A predetermined time period after the initial power increase, the first pre-distortion function stops being applied to the signal, and a second pre-distortion function is generated on the basis of a second set of DPD parameters and applied to the signal. Shortly before a subsequent discrete power increase is applied to the device, the first pre-distortion function is generated on the basis of the first set of DPD parameters and applied to the signal.

A transmission method simultaneously transmitting a first modulated signal and a second modulated signal at a common frequency performs precoding on both signals using a fixed precoding matrix and regularly changes the phase of at least one of the signals, thereby improving received data signal quality for a reception device.

A wireless device includes a plurality of antenna and a plurality of wireless modules that transmit or receive signals via the plurality of antennas. Each of the plurality of wireless modules includes: a generator that generates a high-frequency signal; and a high-frequency circuit that transmits or receives, based on the generated high-frequency signal, a signal via at least one of the plurality of antennas. The wireless device further includes a controller. The controller obtains, each time the plurality of wireless modules start generation of a plurality of the high-frequency signals, a difference of phases of the plurality of high-frequency signals, and controls, based on the obtained difference, at least one phase of a plurality of signals to be transmitted or received by the plurality of wireless modules.

According to some embodiments, a method of transmitting a radio signal in a first wireless network element comprises receiving, at an input of a radio transmitter, a signal for wireless transmission; selectively performing a signal linearization technique on the signal; amplifying the signal with a non-linear amplifier; and transmitting the amplified signal to a second wireless network element. According to particular embodiments, selectively performing the signal linearization technique comprises determining a modulation order of the received signal and determining the modulation order exceeds a modulation order threshold.

A method, an apparatus, and a transceiver for cancelling multi-carrier transmission interference are provided. The method includes: collecting a high order intermodulation signal in radio frequency signals output by a transmitter; processing the high order intermodulation signal so as to generate a first digital signal; establishing a high order intermodulation model by using the first digital signal and a first baseband signal output by the transmitter; generating a second digital signal by using a coefficient of the high order intermodulation model and a second baseband signal output by the transmitter; and counteracting interference in a digital signal output by a receiver with the second digital signal. By using the embodiments of the embodiments of the invention, high order intermodulation interference of a multi-carrier transmitter on a receiver can be effectively canceled, and therefore, difficulty in duplexer design and requirements on a suppression degree are reduced.

Embodiments of the present disclosure disclose a wireless transceiver. The wireless transceiver includes a second control switch, and the second control switch may selectively connect a signal output end of a coupler or a signal output end of a low noise amplifier LNA to a signal input end of the down converter. Therefore, when the signal output end of the coupler is connected to the down converter, the coupler, the down converter, and the analog-to-digital converter ADC form an observer; when the second control switch connects the signal output end of the low noise amplifier LNA to the signal input end of the down converter, a transceiver antenna, the low noise amplifier LNA, the down converter, and the analog-to-digital converter ADC form a receiver. Therefore, the embodiments of the present disclosure can greatly save hardware costs of a system for implementing an observer circuit.

A system that includes combiner circuitry configured to combine a first signal and a second signal to generate a third signal, wherein said third signal is output for transmission onto a communication medium. The system also includes nonlinearity modeling circuitry configured to model a nonlinear response of a nonlinear circuit, and generate a fourth signal through nonlinear distortion of a fifth signal using said model. The system also includes bin modification circuitry configured to generate said second signal through application of one or more weighting factors to frequency bins of said fourth signal, or of a transformed version of said fourth signal, and determine said weighting factors based on a difference, or squared difference, error metric.

A predistortion processing apparatus: an auxiliary feedback module, configured to: extract a nonlinear distortion signal from an analog signal, and input an obtained feedback signal corresponding to the nonlinear distortion signal into an auxiliary model coefficient training module; the auxiliary model coefficient training module, configured to: train an auxiliary coefficient according to the feedback signal and a predistortion signal, and transmit a first auxiliary coefficient obtained through training to a predistortion processing module; a radio frequency signal feedback module, configured to extract a fundamental wave feedback signal; a predistortion model coefficient training module, configured to: train a predistortion coefficient according to the predistortion signal and the fundamental wave feedback signal, and transmit an obtained predistortion coefficient to the predistortion processing module; the predistortion processing module, configured to: perform predistortion processing on an input intermediate frequency signal by performing nonlinear modeling according to the first auxiliary coefficient and the predistortion coefficient.