Local oscillator circuit and joint local oscillator shared circuit

Abstract

The embodiment of the invention provides a local oscillator circuit. The circuit comprises a local oscillator source, a first switch, a first amplifier, a power divider, a second switch, a controllable attenuator, a second amplifier and an external local oscillator interface. The local oscillator source is connected with a first fixed end of the first switch. A second fixed end of the first switchis connected with an output end of the second amplifier. A moving end of the first switch is connected with input of the first amplifier. The output of the first amplifier is connected with a combination end of the power divider. A shunt end of the power divider is connected with the first fixed end of the second switch and an AAU (Active antenna Unit) transceiving channel and calibration channel. The input of the controllable attenuator is connected with the second fixed end of the second switch. The output of the controllable attenuator is connected with the input end of the second amplifier. The moving end of the second switch is connected with the external local oscillator interface. The embodiment of the invention also provides a joint local oscillator shared circuit.

Description

technical field [0001] The embodiments of the present invention relate to the technical field of wireless communication, and in particular, to a local oscillator circuit and a combined common local oscillator circuit. Background technique [0002] In a Time Division Duplexing (TDD) system, since the transceivers share the same propagation channel (and the frequency is the same), the uplink channel can be considered to be equal to the downlink channel in theory. However, in terms of physical implementation, the radio frequency end of each antenna needs Two sets of circuits are used to complete signal transmission and reception respectively. It is difficult for the two sets of circuits to have exactly the same characteristics, which leads to impaired channel reciprocity. Antenna calibration is required to achieve uplink and downlink channel reciprocity. The uplink and downlink channels use the same local oscillator signal, which eliminates the phase error caused by frequency d...

AI Technical Summary

Problems solved by technology

[0003] However, in the scenario where multiple active antenna units (Active antenna Unit, AAU) are required for correction, since different AAUs use their own local oscillator chips, even if the baseband clock (Clock, CLK) signal is the same, different local The phase noise between the signals of the vibration chip is still different, so the phase difference of the signal channels of each AAU cannot cancel each other out.

Images