Abstract: The present disclosure relates to a remote radio unit (RRU), which is connected to a baseband unit (BBU) and an antenna, comprising: a service transmit channel configured to transmit a first correction signal through the antenna, and a standing wave detecting circuit associated with the service transmit channel, wherein: a working frequency of the standing wave detecting circuit is consistent with the service transmit channel, and the standing wave detecting circuit is capable of detecting a standing wave ratio of the service transmit channel and is configured to receive a correction signal looped back by the antenna, and send the correction signal looped back by the antenna to the BBU, wherein the correction signal looped back by the antenna comprises a portion of the first correction signal reflected by the antenna and is used for a calculation of a correction coefficient of the service transmit channel.

Abstract: A master-slave circuit is disclosed that maintains synchronization between two integrated circuit chips, using minimal chip resources. In one embodiment, a single, bidirectional communication path is shared by the two chips. Meanwhile, only one I/O port on each chip is used to send and receive signals via the bidirectional communication path. The first chip to detect a signal event is designated the master and controls the bidirectional communication path. The master can communicate the status to the other chip by controlling the logic state of the I/O ports. When the second chip detects that the I/O port is controlled by the first chip, the second chip will logically deduce that it is now the slave. If both chips detect the signal event at substantially the same time, one of the two chips is pre-programmed to assume control of the I/O port as the master.

Abstract: An active stylus is capacitively coupled to a capacitive touch panel for communication. The active stylus operates in a wait mode to receive initial communications from the panel. In response to such receipt, the active stylus synchronizes to a repeating communications frame implementing time division multiplexing. Communications from the active stylus to the panel include: information communications; synchronization communications and communications specific for columns and/or rows of the panel. Communications from the panel to the active stylus may be addressed uniquely to the stylus or commonly to a group of styluses.

Abstract: A start/stop condition detection circuit is coupled to receive the SDA and SCL signals from an IIC Bus. The circuit generates a first signal in response to an edge of the SDA signal and generates an inversion of the first signal as a second signal in response to an opposite edge of the SCL signal. The first and second signals are logically combined to generate an output signal. The particular directions of the edges of the SDA and SCL signals that the circuit is response to determines whether the output signal is indicative of a start condition detection or a stop condition detection.