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Direct sequential CDMA linking transferring method

A transmission method and a technology for transmitting signals, which are applied in the field of direct-sequence code division multiple access transmission, and can solve the problems of reduced accuracy of channel estimation and reduced accuracy of transmission power control, etc.

Inactive Publication Date: 2002-05-29
KOKUSA ELECTRIC CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This will lead to such a problem that as the fading fluctuation speed increases, the accuracy of the channel estimation will decrease
In addition, since the transmission power control is also implemented on the insertion interval of the pilot symbol, that is, the measurement is inserted into such as Figure 19 The received signal power at the position of the pilot symbol at the same position in each frame of each code channel is shown. Another problem caused by this is that the accuracy of the transmission power control decreases with the increase of the fading fluctuation speed. will reduce

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  • Direct sequential CDMA linking transferring method
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  • Direct sequential CDMA linking transferring method

Examples

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Embodiment 1

[0070] figure 1 An example of the channel structure of the DS-CDMA transmission system according to the present invention is given. Such as figure 1 As shown, each frame of a code channel with a basic transmission rate fb contains pilot symbols and information data whose information rate is spread by a spreading factor (processing gain) to a wideband signal. Such N-code multiplexing of the fundamental channels enables information to be transmitted at a transmission rate of N x fb bps, assuming that all channels have the same quality as the fundamental channels. In this case, if a certain common spreading code is used to spread the pilot symbols of N code channels, the correlation between the respective code channels can be eliminated. Since the code channels all experience the same fading in multi-code multiplexed transmission, the same pilot symbols can be used jointly. figure 2 gives a different figure 1 A channel structure in which only one code channel transmits pi...

Embodiment 2

[0080] Figure 11 Another example of the channel structure of the DS-CDMA transmission system according to the present invention is given. Such as Figure 11 As shown, each frame of a code channel with N basic transmission rates fb contains pilot symbols and information data, the information rate of which is expanded by a spreading factor (processing gain), thereby producing a wideband signal. Multiplexing of N codes of these fundamental channels enables information to be transmitted at a transmission rate of N × fb bps, where the N code channels are divided into K blocks, if all channels have the same quality as the fundamental channels , each block contains H code channels, where N is the number of multiplexed code channels, K is the number of blocks, H is the number of code channels in each block, and N=H×K. The integer K can be even or odd. The H code channels in the same block have pilot symbols inserted at the same position in the frame. For all pilot symbols in diff...

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Abstract

A DS-CDMA transmission method capable of improving the accuracy of channel estimation using pilot symbols by eliminating cross-correlation between pilot symbols inserted into code channels in CDMA multiplexing carrying out fast signal transmission. In each frame assembler, the pilot symbols, which are used for channel estimation for coherent detection, are inserted into coded information data on code channels at fixed intervals, and then the data is modulated by the modulator. The modulated data symbols in each code channel from the modulator are spread by the spreading modulator, the pilot symbols are spread using a spreading code, whereas the information symbols are spread using different spreading codes assigned to respective code channels.

Description

[0001] This application is a divisional application of Chinese Patent Application No. 97113052.3. technical field [0002] The present invention relates to a kind of direct sequence code division multiple access transmission method (DS-CDMA) that utilizes spread spectrum in mobile communication to realize multiple access connection, especially relates to the DS-CDMA transmission method that realizes code multiplexing of a plurality of code channels . Background technique [0003] Recently, research and development of the DS-CDMA system has been concentrated as a new generation of mobile communication systems. The DS-CDMA transmission system enables communication among multiple users using the same frequency band, and identifies individual users by spreading codes appropriately allocated to each user. [0004] The DS-CDMA system is superior to the frequency division multiple access or time division multiple access system in that it can increase the number of simultaneous use...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H04W88/00H04B1/707H04B7/24H04B7/26H04J11/00H04J13/00
CPCH04B7/2637H04J13/0077H04J13/00H04B2201/70701H04J13/18
Inventor 大川耕一大野公士佐和桥卫上林真司奥村幸彦
Owner KOKUSA ELECTRIC CO LTD