Frequency deviation estimation method and receiving terminal in time division-synchronization code division multiple access (TD-SCDMA)

Abstract

The invention relates to mobile communication and discloses a frequency deviation estimation method and a receiving terminal in time division-synchronization code division multiple access (TD-SCDMA). In the invention, rough frequency deviation is estimated by using a characteristic that a training sequence has front 16 chips and tail 16 chips which are completely same during the transmission. Under the condition that high-speed movement contains remarkable main path, the rough frequency deviation can be simply and effectively estimated. Meanwhile, the accurate frequency deviation obtained by the prior art has larger error than the real frequency deviation under the condition of low signal to noise ratio or large frequency deviation, therefore, the estimated rough frequency deviation is more accurate by using the characteristic of the training sequence. Furthermore, the phase compensation is carried out on the time slot data of the large frequency deviation, which can effectively neutralize the influence of the rotation of the large frequency deviation and enables the detected data to be more accurate.

Description

technical field [0001] The invention relates to mobile communication, in particular to frequency deviation measurement technology and phase compensation technology in mobile communication. Background technique [0002] In mobile communication, there is often a large frequency deviation between the crystal oscillator of the mobile terminal and the crystal oscillator of the base station. Moreover, due to various interferences in the mobile communication environment, such as multiple access interference, multipath frequency spread, Doppler frequency shift, etc., the channel performance is degraded, and the signal quality is not as good as that of wired communication. For example, when the receiving end is moving at a certain rate relative to the sending end, the received signal will have a Doppler frequency shift, and the frequency offset is proportional to the relative speed. If the frequency offset exceeds a certain level, it will cause communication quality Malignant declin...

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Problems solved by technology

[0005] However, the inventors of the present invention found that in the patent application No. 200410000119.5, since the channel estimation itself is performed at high speed, the estimated channel itself is already inaccurate, so the frequency offset estimation error larger

Moreover, if the technical solution whose application number is 200510057108.5 is adopted, the complexity is very large

In addition, in the patent application number 97115151.2, when the frequency offset is reversed, the frequency offset is large, which will lead to hard-judged data errors, so the accuracy of the frequency offset estimation is poor

That is to say, the existing methods of reconstruction through training sequence or hard judgment after demodulation, either have a large frequency deviation, or misjudgment, or the complexity is too high

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