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Spread spectrum receiver

A receiver and spread spectrum technology, which is applied in the field of spread spectrum receivers, can solve problems such as performance improvement of inseparable multipath reception combination

Inactive Publication Date: 2003-10-29
NEC CORP
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  • Summary
  • Abstract
  • Description
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Problems solved by technology

[0004] Since the number of multipath components varies greatly between one spread spectrum signal and another spread spectrum signal, if the actual number of multipath components is less than the number of despreaders, the combining performance of rake reception cannot be evaluated. Improve

Method used

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Embodiment Construction

[0024] Referring to FIG. 1, it shows a multi-user CDMA (Code Division Multiple Access) rake receiver of the present invention which receives a plurality of spread spectrum signals for M users respectively. Spread spectrum signals are transmitted from one or more transmission sources, such as cell site base station transmitters, to a plurality of users of a spread spectrum receiver.

[0025] Due to differences in ground characteristics and conditions, the transmitted signal propagates through multiple paths with different (length) propagation delay times, or through a multipath fading channel. For a given spread spectrum signal, there may be as many multipath channels as there are transmitters per unit location, or there may be only one propagation path, depending on the multipath environment of the spread spectrum signal.

[0026] In the first embodiment of the invention, only one antenna 10 is used for a multi-user spread spectrum receiver. The spread spectrum receiver conta...

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Abstract

The spread spectrum receiver includes a multi-stage despreader and a multi-stage rake receiver combiner which are respectively related to the spread spectrum signal. The distribution circuit detects components of the received spread spectrum signal, and divides the despreader group into a plurality of despreader groups so that the divided groups correspond to the received spread spectrum signal, and each group has one or more multiple path components, and assign each group of despreaders to the corresponding rake receive combiners. All despreaders are provided in a number less than the product of the number of rake receive combiners and the maximum number of possible multipath components of the spread spectrum signal but greater than the number of rake receive combiners.

Description

technical field [0001] The present invention relates to a spread spectrum receiver, more particularly to a spread spectrum receiver providing multiple rake combiners for multiple users. Background technique [0002] In a multipath environment, transmitted radio signals are reflected away from objects such that multipath reflected radio waves reach the receiver at different times depending on the length of the propagation path. In a CDMA (Code Division Multiple Access) cellular communication network, transmitters at more than one cell location use the same PN code and simultaneously transmit spread spectrum signals on the same carrier frequency in order to modulate the signal. As a result, the mobile bit can obtain the characteristics of PN modulation by splicing the received signal of the same sequence of PN codes that are mutually delayed, and using a known rake receive combiner to maximize the spread spectrum multipath signal. A combination of ratios and generate a high l...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H04J13/00H04B1/7115H04B7/06
CPCH04B1/7115H04B7/0602H04B2201/7071H04B1/7117H04B2201/70707
Inventor 海野义博
Owner NEC CORP
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