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Method for producing spread-spectrum code with low interference window from CCK code

A spreading code and low-interference technology, which is applied in the field of constructing spreading codes with low-interference windows, can solve problems such as limiting performance

Inactive Publication Date: 2007-07-04
FOUNDER BROADBAND NETWORK SERVICE
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Problems solved by technology

However, it is relatively sensitive to ICI (inter-subcarrier interference) caused by frequency offset or Doppler spread, which becomes the main factor limiting its performance.

Method used

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Embodiment Construction

[0026] The characteristic of the low-interference window spreading code is that the correlation value of its acyclic autocorrelation and acyclic cross-correlation sequences near zero offset is relatively small, close to zero. In other words, let the codeword sequence be C n =(c 1 n , c 2 n ,... c N n ), n=1, 2, ..., M, N is the codeword length, M is the number of codewords, and the acyclic correlation sequence defining the codeword sequence is

[0027] R ij (n)=c 1 i c 1+n j +c 2 i c 2+n j +...+c N-n i c N j n=-N+1,-N+2,...,N-1

[0028] For spreading codes with low interference window characteristics, when -Wij {|R ij (n)|} is closer to zero (R ii (0)=N, so R is not considered when considering the low-interference window characteristics ii (0)).

[0029] Below utilize CCK (Complementary Code Keying) yard to construct the method that has low interference window spreading code to divide into two steps:

[0030] One, choose a CCK code with a spreadin...

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Abstract

The invention discloses a method that uses CCK code to produce the low interference window spreading code, in which, the non-cyclic self-related and non-cyclic inter-related sequences of the low interference window spreading code are less than the predetermined values in the vicinity of zero-offset, including the following steps : 1) according to the spreading gain, choose CCK code ; 2) according to the cost function being the minimum or less than the predetermined value, ensure that the associated value is minimum or less than the predetermined value CCK weight code. The low interference window spreading code can be used for time-domain spreading communication systems, better overcoming the multi-path interference of wireless channel, and meanwhile, reducing the multi-user interference; it also can be used for OFDM communication systems, processing frequency domain spreading modulation in the OFDM frequency domain, which can reduce ICI interference due to frequency shift or Doppler expansion.

Description

technical field [0001] The invention relates to a method for constructing a spreading code with a low interference window, which belongs to the technical field of mobile communication. Background technique [0002] The difficulty of wireless communication mainly comes from the frequency selective fading and time selective fading of wireless channels. At present, the modulation methods with better performance under wireless channel conditions mainly include Code Division Multiple Access (CDMA) spread spectrum modulation and Orthogonal Frequency Division Multiplexing (OFDM) modulation methods. [0003] For the CDMA spread spectrum modulation method, the fading and interference caused by the multipath of the wireless channel can be better overcome by using the good correlation characteristics of the spread spectrum code. At the same time, in the actual communication system, the channel bandwidth is relatively wide, and the spread spectrum gain is not It is very large, and the ...

Claims

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Application Information

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IPC IPC(8): H04B1/707H04B1/711
Inventor 康良川
Owner FOUNDER BROADBAND NETWORK SERVICE
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