Apparatus and method for estimating and compensating sampling frequency offset

Abstract

The invention discloses device and method for sampling frequency offset estimation and compensation, particularly device and method for executing the calculation of phase difference by mathematical linear method to reduce the application of the multiplier and the storage circuit thereof in the sampling frequency offset estimation and compensation. In a preferable embodiment, the method comprises the following steps: receiving signals by employing a sampling frequency offset estimation circuit, then calculating the phase value of each signal, capturing pilots in the signals, calculating the phase difference by subtracting the received singles from the pilots after several symbol delays, further storing the phase difference by employing a phase difference storing circuit, calculating the phase difference between two neighbor symbols by employing the accumulation and the least error sum of squares circuit, calculating the estimated value of sampling frequency offset of the communication system according to the phase difference, and applying the estimated value to compensate the sampling frequency offset.

Description

technical field [0001] The present invention relates to a sampling frequency offset estimation and compensation device and method, in particular, a circuit for storing signal phase values ​​and a sampling frequency offset estimation and compensation circuit for calculating phase difference values ​​are used to replace known storage circuits and multipliers. Background technique [0002] A system using Orthogonal Frequency Division Multiplexing (OFDM) as a modulation architecture, such as 802.11a, is very sensitive to frequency offset. There are two main reasons for this frequency offset. The first is that the frequency oscillator at the transmitting end and the frequency oscillator at the receiving end do not have the same frequency; the second is the Doppler effect caused by the movement of the wireless terminal device. (Doppler Effect). Because the frequency offset will cause the so-called Intercarrier Interference (ICI) to the OFDM system, which will greatly reduce the s...

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Problems solved by technology

[0033] In addition, the operation of the complex number divider used in the above equalizer circuit is very complicated. The common method needs to use a complex number multiplier, a divider, two multipliers, an adder, and a square root operation

[0034] It is known from the known technology that since the sampling frequency offset estimation circuit uses a circuit for storing complex values ​​of the signal to store the signal and a circuit for multiplying the conjugate for phase subtraction, the consumption of hardware will increase

What's more, when the sampling frequency offset estimation circuit estimates, it cannot work before the equalizer to avoid being affected by channel conditions, but must be estimated after the equalizer, so the estimation quality is limited by the equalizer, so that the sampling frequency The convenience and integration of the offset estimation circuit is very low

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