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Method of realizing multiuser detector in ultrashort pulse light CDMA system

An optical code division multiple access and ultrashort pulse technology, which is applied in transmission systems, multiplexing communications, electromagnetic wave transmission systems, etc., to achieve the effects of suppressing multiple access interference, suppressing the impact of system performance, and improving bit error rate characteristics

Inactive Publication Date: 2006-01-25
SHANGHAI JIAOTONG UNIV
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Problems solved by technology

Multi-user detection technology has been widely used in wireless code division multiple access system (especially the third generation mobile communication system) and optical code division multiple access system implemented in time domain to suppress the impact of multiple access interference on system performance, but it The application in the ultrashort pulse optical code division multiple access system is still a blank, and there are no reports of relevant research results at home and abroad

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  • Method of realizing multiuser detector in ultrashort pulse light CDMA system
  • Method of realizing multiuser detector in ultrashort pulse light CDMA system
  • Method of realizing multiuser detector in ultrashort pulse light CDMA system

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[0030] The technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and through specific embodiments.

[0031] figure 1 The implementation block diagram of the J-level OEH-PIC detector is adopted for this sub-invention.

[0032] In order to get the i-th data vector b for all users i The jth (1≤j≤J) estimated value of  i (j), need to know  i-1 (j-1),  i (j-1) and  i+1 (j-1). By analogy step by step, in order to obtain  i (j), it is necessary to know the first-level estimated value i-(j-1) (1),..., i (1),..., i+(j-1) (1), thus requiring a delay of (j-1)T b (T b is the data bit period). Due to the reconstruction of multiple access interference in each stage of detection, i (k) (j) The required operations do not exceed 2(M-1) additions, and the J-level detection requires a total of 2(J-1)(M-1) operations, so the binary time of the J-level OEH-PIC detector The complexity (TCB) is O(2JM), which ...

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Abstract

The method of realizing multiuser detector in ultrashort pulse light CDMA system adopts photoelectronic mixed detection mode and has parallel interference eliminating multistage structure. Traditional single-user detector is used as the first stage of detector, and subsequent stages has re-constituted multiaddress interference on the basis of the preceding stage detection as the basis of re-judging. The present invention has calculation complexity related linearly with the number of users and the number of the stages in the system. Therefore, the present invention can inhibit the influence of multiaddress interference on system performance and greatly improve the error code rate characteristic of great capacity system while controlling the calculation complexity.

Description

Technical field: [0001] The invention relates to a multi-user detector implementation method in an ultrashort pulse optical code division multiple access system, which is mainly applied to optical fiber backbone networks, computer local area networks, optical fiber sensor networks and optical fiber access based on ultrashort pulse optical code division multiple access technology network. Background technique: [0002] Traditional optical communication systems use intensity modulation and direct detection, so optical address codes generally take unipolar codes (0, 1) instead of bipolar codes (-1, +1). Therefore, in the initial stage of research on optical code division multiple access systems, most of the research is based on the unipolar realization of address codes. Although unipolar codes have their own advantages in the application of optical code division multiple access systems, their orthogonality and ability to accommodate users are poor, and this is the main reason ...

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H04J15/00H04B17/00H04M15/00H04B10/071H04J99/00
Inventor 张海滨黄培中宋文涛李荣玉李毓麟
Owner SHANGHAI JIAOTONG UNIV
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