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Hybrid carrier direct sequence code division multiple access (CDMA) transmission system

A direct sequence spread spectrum and transmission system technology, applied in the field of wireless communication, can solve the problem of MC-CDMA system peak-to-average height, etc., and achieve the effect of improving system bit error performance, uniform signal energy distribution, and reducing peak-to-average ratio

Inactive Publication Date: 2011-06-22
HARBIN INST OF TECH
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Problems solved by technology

[0004] The present invention is to solve the problem of high peak-to-average ratio of the existing MC-CDMA system, and to improve the system bit error performance under the selective fading channel, and to provide a mixed-carrier direct-sequence spread spectrum CDMA transmission system

Method used

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  • Hybrid carrier direct sequence code division multiple access (CDMA) transmission system
  • Hybrid carrier direct sequence code division multiple access (CDMA) transmission system
  • Hybrid carrier direct sequence code division multiple access (CDMA) transmission system

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specific Embodiment approach 1

[0023] Specific embodiment one, specific embodiment one, combine figure 1 and figure 2 Describe this specific embodiment, a kind of mixed carrier direct sequence spread spectrum CDMA transmission system, adopt the sequence that length is N as the address code to distinguish the user in the system, and the sequence that user i adopts is The N is a positive integer; i is a positive integer;

[0024] Signal sending process:

[0025] Step 1. Let the input data of user i be And divide the continuous L data into one group, perform serial / parallel conversion on the group of data, and obtain L-way parallel data; for example, the The parallel data obtained after serial / parallel conversion is recorded as where T represents transpose;

[0026] Step 2. Use the sequence corresponding to user i for each path of parallel data obtained in step 1 Perform sequence extension to obtain the sequence after L-way extension; use data For example, after time-domain expansion of the seque...

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Abstract

The invention discloses a hybrid carrier direct sequence code division multiple access (CDMA) transmission system, which relates to the field of wireless communication, solves the problem of relatively higher peaks of a conventional multi-carrier system and improves the bit error rate performance of the system in a selective fading channel. In the system, a transmitter performs time domain sequence extension on transmitted data, and realizes multiple access by adopting a method for combining a CDMA technology and weighted fractional Fourier transform; and a receiver transforms the data to a fractional Fourier transform domain again according to the reversibility of the weighted fractional Fourier transform, and performs sequence de-extension to obtain output data. The system is suitable for hybrid carrier signal transmission.

Description

technical field [0001] The invention relates to the field of wireless communication, in particular to a CDMA transmission system. Background technique [0002] In the current communication system, there are mainly two modes of single-carrier transmission and multi-carrier transmission. The digital communication system based on weighted fractional Fourier transform (WFRFT) has the characteristics of single-carrier and multi-carrier mixed modulation. On the frequency plane, it has been initially applied in the field of communication. [0003] Code Division Multiple Access (CDMA) technology is a multiple access scheme, which uses the orthogonality between code words to allocate different code sequences to different users to achieve multiple access. CDMA technology adopts the method of sequence expansion, which expands a transmission symbol into a sequence of a certain length for transmission. If the sequence is extended in the time domain, DS-CDMA (Direct Sequence Spread Spe...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H04L27/26
Inventor 沙学军邱昕梅林吴宣利迟永钢
Owner HARBIN INST OF TECH
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