Maxlinear, Inc.

Other

Csr Technology Inc.

Stephane Laurent-Michel

Curtis Ling

Glenn Chang

Sheng Ye

Anand Anandakumar

Raja Pullela

Andrew Joo Kim

Vamsi Paidi

Stephen A Jantzi

Subramanian Anantharaman Chandrasekarapuram

Raghuraman Mariappan

Oliver Skull

Alan Doak

Wen-Chi Tu

Systems and methods are provided for receiver nonlinearity estimation and cancellation. Narrowband (NB) estimation may be performed in a receiver during handling of received radio frequency (RF) signals. The narrowband (NB) may include generating estimation channelization information relating to received RF signals; generating reference nonlinearity information relating to one or more other signals, which may cause or contribute to nonlinearity that affects the processing of the received RF signals; and generating, based on the estimation channelization information relating to the received RF signals and the reference nonlinearity information relating to the other signals, control data for configuring nonlinearity cancellation functions. The received RF signals may be channelized, and the estimation channelization information may be generated based on the channelization of the received RF signals. The other signals may be channelized, and the reference nonlinearity information may be generated based on the channelization of the other signals.

Receiver nonlinearity estimation and cancellation

Aspects of methods and systems for PAPR reduction in a microwave backhaul outdoor unit are provided.

PAPR reduction in a microwave backhaul outdoor unit

A first microwave backhaul assembly comprises a first antenna, a front-end circuit, an inter-backhaul-assembly interface circuit, and an interference cancellation circuit. The first antenna is operable to receive a first microwave signal. The front-end circuit is operable to convert the first microwave signal to a lower-frequency digital signal, wherein the lower-frequency digital signal has energy of a second microwave signal and energy of a third microwave signal. The inter-backhaul-assembly interface circuit is operable to receive information from a second microwave backhaul assembly. The interference cancellation circuit is operable to use the information received via the inter-backhaul-assembly interface circuit during processing of the lower-frequency digital signal to remove, from the first microwave signal, the energy of the third microwave signal. The information received via the inter-backhaul-assembly interface may comprise a signal having energy of the second microwave signal.

Interference cancellation in microwave backhaul systems

A system comprises a microwave backhaul outdoor unit having a first resonant circuit, phase error determination circuitry, and phase error compensation circuitry. The first resonant circuit is operable to generate a first signal characterized by a first amount of phase noise and a first amount of temperature stability. The phase error determination circuitry is operable to generate a phase error signal indicative of phase error between the first signal and a second signal, wherein the second signal is characterized by a second amount of phase noise that is greater than the first amount of phase noise, and the second signal is characterized by a second amount of temperature instability that is less than the first amount of temperature instability. The phase error compensation circuitry is operable to adjust the phase of a data signal based on the phase error signal, the adjustment resulting in a phase compensated signal.

Outdoor unit resonator correction

Systems and methods are provided for receiver nonlinearity estimation and cancellation. During processing of received radio frequency (RF) signals, it may be determined when one or more other signals, different from the received RF signals, cause nonlinearity affecting processing of the RF signals, and one or more cancellation adjustments may be applied during processing of the RF signals, for mitigating effects of the nonlinearity. Determining the one or more cancellation adjustments may be based on narrowband (NB) estimation of the effects of the nonlinearity, and the one or more cancellation adjustments may be configured as wideband (WB) corrections. The NB estimation may be applied based on channelization of the received RF signals. The NB estimation may comprise generating reference nonlinearity information relating to the one or more other signals, and generating, based on the reference nonlinearity information, control data for configuring the one or more cancellation adjustments.

A system comprises a modulator circuit, a test signal generator circuit, and a control circuit. The modulator circuit is operable to generate a data-carrying signal based on a reference signal. The test signal generator circuit is operable to generate a test signal based on the reference signal. The control circuit is operable to determine current status of a microwave backhaul link. The control circuit is operable to configure a nominal frequency at which the test signal generator circuit generates the test signal based on the determined status of the microwave backhaul link. The control circuit is operable to determine an amount of whitespace to have on either side of the test signal based on the current status of the microwave backhaul link. The control circuit is operable to configure the modulator circuit such that the data-carrying signal has the determined amount of whitespace surrounding the nominal frequency of the test signal.

Phase noise suppression

Noise caused by and leaking from a transmit signal into a radio-frequency (RF) receive path signal is reduced by forwarding the transmit signal to a first filter or a digital processor and DAC, scaling the transmit signal and approximating the noise, subtracting first and second corrective signals from the RF receive path signal, down-converting a resulting corrected RF receive path signal, filtering the down-converted corrected signal in a second filter, up-converting the filtered corrected signal to create the first corrective signal, and up-converting the filter or DAC output signal to create the second corrective signal. The transmit signal may come from an output of an RF power amplifier, and may be down-converted prior to filtering in the first filter or processing in the digital processor. The second filter may be a series filter or a shunt filter. A radio includes the circuits to perform the above method.

Method and system for mitigating the effects of a transmitted blocker and distortions therefrom in a radio receiver

A radio receiver processing path has a mixer with active interference/blocker cancellation to reduce the intensity of leaked and undesired signals by using a replica of the transmitted signal, emulating the phase and attenuation through the leakage path and subtracting the emulated signal within the mixer. Intermodulation distortions are predicted through the use of nonlinear modeling in the digital baseband between the baseband transmitter and baseband receiver and subsequently subtracted from the received signal. The nonlinear basis functions are combined to model the composite nonlinearity in the signal path based on digital baseband transmitted data. The modeled nonlinearity is subtracted from the received signal, and the result is observed and used to guide the nonlinear modeling parameters using self-contained control loops.

Canceling distortion in the receive path of a radio is achieved by down-converting an RF transmit signal to cancel leakage and intermodulation noise in a receive path baseband or intermediate frequency signal. Cancelation may be combined with digital pre-distortion of the transmit signal. Processing may be applied to optimize cancelation. Further cancelation can be achieved by re-modulating the demodulated and error-corrected receive signal, and predicting distortion caused by the transmit path. The cancelation system may be calibrated using a test signal.

Method and system for signal dynamic range improvement for frequency-division duplex communication systems

A transmitter comprises a local oscillator circuit operable to generate a reference signal, a modulator circuit operable to generate a data-carrying signal using the reference signal, and a test signal generator circuit operable to generate a test signal using the reference signal. The test signal has a first bandwidth, and a test signal insertion circuit is operable to combine the data-carrying signal and the test signal to generate a combined signal. An amount of bandwidth in the combined signal allocated to the test signal is greater than the first bandwidth such that a component of the combined signal corresponding to the test signal is bordered by whitespace. A receiver may then use the test signal to determine and correct for phase noise introduced in the transmitter.

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Carlsbad, CA, United States of America

Stephane Laurent-Michel