Smsc Holdings Sarl

Telefonaktiebolaget Lm Ericsson (publ)

Renyuan Li

Ralph Mason

Xiaoming Lai

Christopher Andrew Devries

Justin L Fortier

Jean-Paul Rene Decruyenaere

Peter H R Popplewell

William Kung

Ralph Dickson Mason

A wireless communication device is provided. The wireless communication device comprises a transceiver; an antenna connected to the transceiver through a transmission path; and a compensation circuit configured to or operative to compensate for a passive intermodulation (PIM) interference on the transmission path, the compensation circuit generating a PIM estimate signal based on a transmit signal and a PIM error signal.

PIM compensation at a transmitter's radio frequency port

Transmit power control functionality in wireless audio systems may be implemented by way of a Transmit Power Control (TPC) algorithm devised to control power for both source and sinks in a multi sink session, to reduce power consumption. Information may be passed back and forth between the source and sink devices to adjust power based on the shared information. The TPC algorithm may allow power control on both ends of an RF link, and may have multiple sink devices communicating with a source device. Furthermore, the multiple sink devices and the source device may each be operating at different power levels, and adjust their respective power levels as instructed by the TPC algorithm. Power control is therefore implemented on both ends of the link, where multiple sources and sinks may all operate at different power levels, and all individually adjust their respective power levels.

Transmit power control algorithms for sources and sinks in a multi-link session

An audio amplifier system may include an audio CODEC/output (AOP) path featuring analog class-D amplifiers, and using Natural Sampling Pulse Width Modulation (PWM) to convert an analog input into a series of Rail-to-Rail pulses. The audio signal may be encoded in the average value of the PWM pulse train and may be recovered from the PWM signal by analog low pass filtering. The Class-D amplifiers may be designed with a negative feedback loop/network to compare the output signal with the input signal and suppress non-idealities introduced by the Class-D switching stage. Furthermore, operation of the AOP may be designed according to a separate signal transfer function and a separate noise transfer function, and 2order noise shaping may be performed at low power, with an optimized filter included in the feedback loop to achieve the best noise reduction at low power. Operation of the amplifier feedback network may be similar to that of a continuous time, low-pass delta-sigma modulator, but with a PWM loop wrapped around the class-D power amplifier.

Low-power class D amplifier using multistate analog feedback loops

A wireless communications system and channel-switching method are disclosed herein. A source device and multiple sink devices independently maintain respective counters which track data packet errors. Each device independently switches channels only after its counter reaches a channel-switching threshold. The new channel switched-to is either determined by an indexed ordering of the available channels or by reference to a global clock maintained by each of the devices. Accordingly, all devices quickly arrive at a common channel. The system switches channels only when necessary and resolves quickly to a mutually acceptable channel. Therefore, unnecessary channel switching is minimized and data throughput is optimized.

Growing community of inventors

Ottawa, Canada

Renyuan Li