Abstract: The present invention comprises methods and apparatuses for maintaining radio network timing synchronization across an asynchronous communication link between a Radio Equipment Controller (REC) and an item of Radio Equipment (RE). An REC-side adaptor sends first and second asynchronous packet flows over the asynchronous communication link, including a downlink packet flow comprising CPRI basic frames and overhead information encapsulated in asynchronous communication link packets, and a synchronization packet flow comprising CPRI clock data. An RE-side adaptor recovers the CPRI clock from the synchronization packet flow, and uses the recovered clock to re-synchronize the downlink data recovered from the downlink packet flow. For the uplink, the RE outputs uplink traffic in a synchronous, CPRI-compliant stream that is then encapsulated for asynchronous transport by the RE-side adaptor.

Abstract: A method and apparatus is provided for linearizing the output of a non-linear device, such as a power amplifier. The input signal to the non-linear device is predistorted based on a predistortion model to compensate for distortion introduced by a non-linear device. A wideband feedback signal is generated from the output signal of the non-linear device, and the wideband feedback signal is filtered to generate two or more narrowband distortion signals with predetermined frequencies corresponding to anticipated distortion components in the output signal. Model parameters of the predistortion model are adapted based on the narrowband distortion signals.

Abstract: A method and apparatus is provided for linearizing the output of a non-linear device, such as a power amplifier. The input signal to the non-linear device is predistorted based on a predistortion model to compensate for distortion introduced by a non-linear device. A wideband feedback signal is generated from the output signal of the non-linear device, and the wideband feedback signal is filtered to generate two or more narrowband distortion signals with predetermined frequencies corresponding to anticipated distortion components in the output signal. Model parameters of the predistortion model are adapted based on the narrowband distortion signals.

Abstract: The present invention comprises methods and apparatuses for maintaining radio network timing synchronization across an asynchronous communication link between a Radio Equipment Controller (REC) and an item of Radio Equipment (RE). An REC-side adaptor sends first and second asynchronous packet flows over the asynchronous communication link, including a downlink packet flow comprising CPRI basic frames and overhead information encapsulated in asynchronous communication link packets, and a synchronization packet flow comprising CPRI clock data. An RE-side adaptor recovers the CPRI clock from the synchronization packet flow, and uses the recovered clock to re-synchronize the downlink data recovered from the downlink packet flow. For the uplink, the RE outputs uplink traffic in a synchronous, CPRI-compliant stream that is then encapsulated for asynchronous transport by the RE-side adaptor.