Transmitter-receiver joint frequency selective IQ imbalance estimation and compensation method for self-loopback structures

Abstract

The invention discloses a transmitter-receiver joint frequency selective IQ imbalance estimation and compensation method for self-loopback structures, comprising the following steps: aiming at amplitude distortion and phase deviation of in-phase (I) and quadrature (Q) signals at a radio-frequency front end and different frequency responses of the two signals, designing two self-loopback structures to cascade an up-conversion unit and a down-conversion unit of the signals to obtain two IQ imbalance models; using a frequency domain training sequence to obtain two cascaded equation sets through the two self-loopback structures, solving the cascaded equation sets, and respectively estimating the parameters needed for compensating the frequency points of frequency selective IQ imbalance of a transmitter and a receiver; and compensating frequency selective IQ imbalance of the transmitter and the receiver in a frequency domain according to the compensating coefficients of the frequency points. The method of the invention is low in computing complexity, and can improve the system performance obviously.

Description

technical field [0001] The invention belongs to the technical field of broadband wireless communication, in particular to a method for estimating and compensating in the frequency domain for frequency-selective IQ imbalance in a self-loop structure. Background technique [0002] An increasing number of devices are equipped with wireless communication capabilities, causing wireless systems to move to commodity markets. This means that there is great price competition for wireless products, and efforts are being made to create low-cost solutions. This is especially a problem in multi-antenna systems because they require multiple radio frequency (RF) front ends. Additionally, an increasing number of wireless standards require flexible solutions to support multiple standard protocols simultaneously. [0003] Direct conversion is a promising concept in meeting these needs. Because it does not require an external intermediate frequency (IF) filter and image interference filter,...

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Problems solved by technology

[0008] Purpose of the invention: Aiming at the amplitude distortion and phase deviation problems of the IQ two-way signals existing in the radio frequency front-end and the different frequency response problems, the present invention provides a method for estimating and compensating IQ imbalance of combined frequency selectivity of transmitting and receiving in a self-loop structure. The self-loop structure of the transceiver estimates the imbalance parameters of the transceiver in the frequency domain at the same time, and then compensates the IQ imbalance of the transmitting end and the receiving end according to the estimated parameters

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