Apparatus and method for processing sampling frequency deviation tracking signal in orthogonal frequency division multiplex system

Abstract

A sample frequency offset tracing signal process device of an FDM system and a method includes a digital converter, an inter potation filter, a FIR filter, a serial-parallel transformer, a rough timing test device and a latter timing error test device, among which, an interpolation control loop composed of orderly connected loop filter device, a re-sample control device and a digital control oscillator is set for computing the interpolation control offset value to regulate the interpolation positions by related offset computation between the latter timing error test device and the interpolation filter and the integer part of the timing error got by the latter timing error test device is used to regulate the Fourier transformation computation window position, the decimal fraction part is used as the error input signal of the loop to drive the loop filter and re-sample controller, the digital control oscillator and computing the deviation value by the phase deviation value to regulate the position.

Description

technical field [0001] The invention belongs to the field of wireless digital communication, in particular to a sampling frequency deviation tracking technology based on an orthogonal frequency division multiplexing (Orthognal Frequency Division Multiplexing, OFDM) modulation method. Background technique [0002] Different from the analog communication system, the digital communication system will have D / A and A / D modules. At the sending end, the D / A module converts the digital signal into an analog signal, and then transmits it to the wireless channel through the radio frequency module, while the receiving end The analog signal obtained through the radio frequency module is converted into a digital signal through the A / D module, and then fully digitalized. However, the crystal oscillator characteristics that determine the sampling frequency of the receiver D / A module and the transmitter A / D module cannot be completely the same, resulting in a deviation in the sampling frequ...

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Problems solved by technology

Obviously, this is no different from the general filter function, and loses the advantages of the polynomial interpolation function.

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