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Transmission method for multi-carrier synchronization CDMA

A transmission method, multi-carrier technology, applied in the direction of multi-frequency code system, etc., can solve problems such as unavailability, and achieve the effect of improving transmission rate

Inactive Publication Date: 2012-05-09
CHONGQING WIRELESS OASIS COMM TECHCO
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0009] In order to reduce (ICCI), multi-user detection technology can be used, but when the number of subcarriers and codes is large, it is actually not available, usually only a few subcarriers (such as 2, 4, 8)

Method used

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  • Transmission method for multi-carrier synchronization CDMA
  • Transmission method for multi-carrier synchronization CDMA
  • Transmission method for multi-carrier synchronization CDMA

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0046] Cross-correlation function between two frequencies:

[0047] Let the two frequencies be f 0 and f 1 , Δf=f 1 -f 0 , the cross-correlation function between frequencies is R c (Δf,τ), Δf=mf c , m=1 / N, N is the spreading code length, f c =1 / T c ,T c is the chip length. f α = kf c , k is a positive integer. τ is the time offset,

[0048] R c ( Δf , τ ) = R c u ( Δf , τ ) + R c d ( Δf , τ )

[0049] where R c u (Δf, τ) is the sum frequency term of the inter-frequency cross-correlation function, R c d (Δf, τ) is the difference frequency term of the inter-frequency cross-correlation function...

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Abstract

The invention discloses a multi-carrier synchronous CDMA transmission method, comprising the following: firstly, according to a used frequency band and a moving speed, an OFDM system is determined so as to obtain a two-way OFDM symbol subjected to serial / parallel conversion; secondly, the two-way OFDM symbol with data information is subjected to spectrum spread and modulation by a pair of spectrum spread code words; and finally, the two-way symbol subjected to spectrum spread and modulation is respectively added with a symbol of a cyclic prefix, and the emission is realized by a radio frequency system after the combination. A pair of spectrum spread code words is capable of making a frequency code interference ICCI between different subcarrier waves equal to zero.

Description

technical field [0001] The invention relates to the fields of Code Division Multiple Access (CDMA) and Orthogonal Frequency Division Multiplex (OFDM) wireless communication, in particular to a multi-carrier synchronous CDMA transmission method and its equipment. Background technique [0002] Orthogonal Frequency Division Multiplexing (OFDM) transmission technology has been widely used in communication systems. In wireless mobile communication systems, due to the influence of propagation conditions, various codes, interleaving and diversity are usually used to combat various effects of fading channels. [0003] OFDM is essentially a multiplex technology. In multiple access communication, a single carrier cannot be used as the smallest transmission unit and allocated to different addresses. Instead, OFDMA is usually used as the multiple access method, which reduces the transmission efficiency. In addition, in order to reduce the interference to the adjacent frequency band outs...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H04L27/26
Inventor 陈俊璧陈卫段世平
Owner CHONGQING WIRELESS OASIS COMM TECHCO