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Method for generating signal of non-interference quasi-synchronous CDMA communication system

A code division multiple access and communication system technology, which is applied in the field of signal generation of non-interference quasi-synchronous code division multiple access communication system, can solve the problems of system capacity limitation, reduce the performance of synchronous code division multiple access communication system, etc., and achieve reduction Requirements, Effects of Reduced Implementation Complexity

Inactive Publication Date: 2009-01-28
CHONGQING WIRELESS OASIS COMM TECHCO
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Problems solved by technology

Due to the existence of the near-far effect, the performance of the synchronous code division multiple access communication system will be further reduced, and the system capacity will be limited

Method used

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  • Method for generating signal of non-interference quasi-synchronous CDMA communication system
  • Method for generating signal of non-interference quasi-synchronous CDMA communication system
  • Method for generating signal of non-interference quasi-synchronous CDMA communication system

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Embodiment Construction

[0034] The zero-correlation zone spreading sequence code group proposed by the present invention is equal to the best autocorrelation sequence a of L and the T order Hadamard matrix H by the period and generates by the following method, wherein L=m(2k+1), m>2 , k≥0, T=2 n .

[0035] 1. Calculate s=T -1 (mod 2k+1), construct the initial vector e 0 =(e 0，1 , e 0，2 ,...,e 0，T-1 ), where e 0，t =st(mod L), 0≤t

[0036] 2. Construct a set of vectors e i =(e i，1 , e i，2 ,...,e i，T-1 ), 0≤ii，t =e 0，t +i(2k+1)(mod L), 0≤t<T, and arranged in matrix form as

[0037] E = e 0 , 0 e 0,1 L e 0 ...

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Abstract

The invention discloses a method for generating a signal for an interference-free quasi-synchronous CDMA communication system. A spectrum spreading sequence encode block is a sequence with the zero correlation property generated by an optimal self-correlation sequence and a Hadamard matrix and is suitable for a quasi-synchronous CDMA communication system. When the maximum synchronous error of the system and the maximum multipath delay of the channel are extended within the regulated range, the interference-free transmission is realized. The parameter of the spectrum spreading sequence encode block and the efficiency of the system can be adjusted in real time according to practical factors and to select flexibly. The method lowers the requirement of the CDMA communication system on the power control and the synchronization, and reduces the complexity of realizing the system.

Description

technical field [0001] The invention relates to a direct spread spectrum sequence, in particular to a signal generating method of a non-interference quasi-synchronous code division multiple access communication system. Background technique [0002] In order to reduce the interference in the CDMA communication system, people have proposed a synchronous CDMA communication system, which uses orthogonal Walsh codes or Adachi codes as the set of spreading sequences. For the mobile communication system, the accurate synchronization of the uplink is not easy to guarantee, and the multipath propagation of the wireless channel makes the system synchronization more difficult. The inter-symbol correlation characteristic of Walsh code or Adachi code is only zero when synchronous, and the inter-correlation value is not zero when the code groups are not synchronous, and there is multiple access interference. Due to the existence of the near-far effect, the performance of the synchronous ...

Claims

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Application Information

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IPC IPC(8): H04B1/707H04L27/26H04J13/00H04B1/7107H04J13/12H04J13/14
Inventor 周正春唐小虎范平志郝莉
Owner CHONGQING WIRELESS OASIS COMM TECHCO
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