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Receiver and automatic frequency control method

A receiving device and technology for receiving signals, applied in electrical components, transmission systems, etc., can solve the problems of estimating the known symbol phase rotation amount and deteriorating AFC accuracy.

Inactive Publication Date: 2009-06-17
PANASONIC CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0016] However, since the correlated known symbols are affected by the cross-correlation of spreading codes and the influence of interference, etc., it is difficult for the above-mentioned conventional receiving apparatus to estimate the phase rotation amount between known symbols with high precision, and there is an AFC Accuracy Deterioration Problem

Method used

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  • Receiver and automatic frequency control method

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Embodiment 1

[0040] 4 is a diagram showing a time slot configuration of data transmitted from a base station apparatus that performs wireless communication with a communication terminal apparatus according to Embodiment 1 of the present invention. As shown in FIG. 4, known symbols are inserted into the slightly central portion of the time slot. The known symbol is defined as image 3 Spreading codes generated by the method shown. Also, the data part is multiplied by a spreading code unique to each user.

[0041] The base station apparatus multiplexes and transmits a signal having a slot structure as shown in FIG. 4 to each communication terminal apparatus (user) in communication. Furthermore, each communication terminal apparatus is notified in advance of the base code and the shift amount by transmission and reception of the control signal.

[0042] FIG. 5 is a block diagram showing the configuration of a communication terminal apparatus according to this embodiment. 5 shows the confi...

Embodiment 2

[0081] In the above-mentioned Embodiment 1, when there is only one communication terminal device that communicates with the base station device at present, not only the technical feature of adding the known signal correlation value cannot be exerted, but also the first half of the known symbol and the In the latter half, the phase rotation amount is estimated, and the estimation accuracy of the phase rotation amount may be further deteriorated than that of the prior art.

[0082] In order to solve the above problem, in Embodiment 2, the case where the correlation value for estimating the amount of phase rotation is switched according to the number of shift codes currently in use will be described.

[0083] Fig. 8 is a block diagram showing the configuration of a communication terminal apparatus according to Embodiment 2 of the present invention. In addition, in the communication terminal apparatus shown in FIG. 8 , the same reference numerals are given to the same components a...

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Abstract

A searcher 105 creates a delay profile of a known symbol portion of a received base band signal by using a basic code, and a number-of-codes / kind-of-code determining unit 106 determines the number and kind of shift codes being used, on the basis of the delay profile. Correlators 108-1 to 108-n compute the correlation values between the known symbol first half of the received base band signal and the shift code. Correlators 109-1 to 109-n compute the correlation values between the known symbol second half of the received base band signal and the shift codes. A phase estimation unit 119 estimates the phase rotation per unit time by using the sum of the output signals of the correlators 108-1 to 108-n and the sum of the output signals of the correlators 109-1 to 109-n. As a result, the influence of the cross-correlation of spreading codes and the influence of noises are suppressed, so that the phase rotation between the known symbols can be estimated highly precisely to realize highly precise AFC.

Description

technical field [0001] The present invention relates to a receiving device and an automatic frequency control method for a CDMA wireless communication system. Background technique [0002] In recent years, wireless communication systems such as mobile phones and automobile phones have rapidly spread. In a communication terminal device of a wireless communication system, the receiver device performs automatic frequency control (Automatic Frequency Control; hereinafter referred to as "AFC") to compensate for the deviation of the carrier frequency from the transmitter device. [0003] Below, refer to figure 1 2 illustrates a conventional receiving apparatus. figure 1 It is a diagram showing the slot structure of data transmitted by the transmitting apparatus. FIG. 2 is a block diagram showing the configuration of a conventional receiving apparatus. [0004] like figure 1 As shown, the signal transmitted by the transmitting device (not shown) includes the known symbol 11 an...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H04B1/707
CPCH04B1/709H04B1/707
Inventor 高桥秀行平松胜彦
Owner PANASONIC CORP