A smart antenna calibration method, device and system

Abstract

The invention provides an intelligent antenna calibration method, as well as the device and the system thereof, and estimates the frequency response of the corresponding sub carrier wave position of each transmitting antenna and the channel impact response length of each transmitting antenna according to the received pilot symbols; the maximum value of the channel impact response length and the frequency response of each transmitting antenna are used for the interpolation on the positions of the sub carrier wave without the estimation of frequency response; according to the interpolated frequency response, the compensation coefficient of each transmitting antenna is worked out, and each transmitting antenna gets compensated correspondingly according to the compensation coefficient so as to lead the frequency response of each transmitting channel to be identical. Through the above proposal, the invention can improve the accuracy of estimation, reduces arithmetic operation, reduces disturbance and realize more simply and flexibly.

Description

technical field [0001] The invention relates to the communication field, in particular to a calibration method, device and system for a smart antenna in an OFDM-TDD system. Background technique [0002] In an Orthogonal Frequency Division Multiplexing-Time Division Duplex (OFDM-TDD: Orthogonal Frequency Division Multiplexing-Time Division Duplex) system, a smart antenna technology is introduced to reduce co-channel interference between terminals. The smart antenna technology utilizes the channel estimation of the uplink channel of each terminal to estimate the direction of arrival (DOA, Direction Of Arrival) of the desired terminal, and adds an appropriate weight factor to each antenna in the downlink according to the DOA to make the beam point to the desired terminal, thereby achieving Increase the received signal power of the desired terminal and reduce the same-channel interference between terminals. [0003] However, there is a premise for the use of smart antennas, tha...

AI Technical Summary

Problems solved by technology

However, in the transmission calibration, there are usually N transmission channels (N is the number of transmitting antennas), the signals transmitted by the N transmission channels are superimposed and received in the calibration channel, and the signals of each transmission channel are received by other channels in the calibration channel. The impact of the transmit channel noise, which is equivalent to reducing the received signal-to-noise ratio of each transmit channel pilot symbol at the receiver

[0005] In addition, for the time slot structure of the Long-Term Evolution (LTE, Long Time Evolution) system, the calibration is performed in the free time slot of the uplink and downlink pilot time slots. Due to the echo of the downlink pilot symbols, the subsequent free time slots The calibration signal in the interference will affect the calibration effect

Images