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CDMA (code division multiple access) communication method

A communication method and code division multiple access technology, which is applied in the field of code division multiple access communication, can solve problems such as wasting frequency bands, and achieve the effects of reducing frequency band waste, low bit error rate, and good reliability

Inactive Publication Date: 2015-04-29
HARBIN INST OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to solve the problem of wasting frequency bands by adopting the CP introduced by the OFDM system in the current communication method. The present invention provides a code division multiple access communication method

Method used

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  • CDMA (code division multiple access) communication method
  • CDMA (code division multiple access) communication method
  • CDMA (code division multiple access) communication method

Examples

Experimental program
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specific Embodiment approach 1

[0060] Specific implementation mode one: combine figure 1 , figure 2 , image 3 , Figure 4 , Figure 5 and Figure 6 Describe this embodiment, the code division multiple access communication method described in this embodiment,

[0061] It is implemented traditionally based on BS-CDMA system,

[0062]In the downlink of the system, the transmitting end of BS-CDMA transmits the data to be transmitted for each user:

[0063] Step A1. Multiply the data to be sent by the user with the corresponding Hadamard sequence to perform spectrum spreading to obtain one channel of data;

[0064] Step A2, performing serial / parallel conversion on one channel of data obtained in step A1 to obtain M channels of parallel data;

[0065] Step A3, multiplying the M parallel data obtained in step A2 by the M subcarriers respectively to obtain M processed data; the M subcarriers are discrete data output by M code sequences through FFT;

[0066] Step A4, performing parallel / serial conversion o...

specific Embodiment approach 2

[0119] Specific implementation mode two: combination Figure 7 Describe this embodiment, this embodiment is a further description of the code division multiple access communication method described in the specific embodiment one, the serial data obtained by the user described in step A4 and step C4 is divided into a real part and an imaginary part ;

[0120] The digital / analog conversion in steps A5 and C5 is to carry out digital / analog conversion to the real part and the imaginary part of data respectively;

[0121] The carrier modulation in steps A6 and C6 is to carry out carrier modulation to the real part and the imaginary part after the digital / analog conversion respectively;

[0122] The band-pass filtering in steps A7 and C7 is to carry out band-pass filtering to the real part and the imaginary part after carrier modulation respectively, then the real part and the imaginary part after the band-pass filtering are added together as the final band-pass filtering Signal. ...

specific Embodiment approach 3

[0130] Specific embodiment three: this embodiment is a further description of the code division multiple access communication method described in specific embodiment one, the Hadamard sequence described in step A1 and step C1 is a spreading code, and each string of Hadamard sequences Corresponding to a unique string of code sequences.

[0131] Hadamard sequence C in this embodiment (q) (t) as spreading code, C (q) (t) Ensure that user q is not interfered by other users; each string of Hadamard sequence C (q) (t) corresponds to a unique string of code sequences User q can be protected from multipath effects. Therefore, the system can support K users in total. Below, for C (q) (t) is defined as follows:

[0132] C ( k ) = { c m ( k ) ...

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Abstract

The invention discloses a CDMA (code division multiple access) communication method. The invention relates to a CDMA communication method which is designed for solving the problem that a CP (cyclic prefix) is introduced in an OFDM (orthogonal frequency division multiplexing) system in the current communication method, thereby wasting bands. The method is traditionally implemented based on a BS-CDMA (block spread-code division multiple access) system; a transmitting method for the transmitting ends of a downlink and an uplink comprises the step of sequentially carrying out spectrum spreading, serial-parallel conversion, multiplication with M paths of sub-carriers, parallel-serial conversion, digital-to-analog conversion, carrier modulation and band-pass filtering on data to be transmitted by a user so as to transmit the signals subjected to band-pass filtering to a channel; and a receiving method for the receiving ends of the downlink and the uplink comprises the steps of sequentially carrying out band-pass filtering, demodulation, low-pass filtering, analog-to-digital conversion, serial-parallel conversion, multiplication with M paths of sub-carriers, low-pass filtering, parallel-serial conversion, despreading, and integration and judgment in a bit time Tb on the signals transmitted by a receiving channel of a receiving antenna, and outputting the signals. The method disclosed by the invention is suitable for carrying out wireless communication.

Description

technical field [0001] The invention relates to a code division multiple access communication method. Background technique [0002] In the current communication method, Orthogonal Frequency Division Multiplexing (OFDM) system is mainly used to overcome multipath interference with Cyclic Prefix (CP). The introduction of CP will cause a part of frequency band to be wasted, thereby reducing the utilization rate of frequency band. Contents of the invention [0003] The object of the present invention is to solve the problem of wasting frequency band by adopting the CP introduced by the OFDM system in the current communication method, and the present invention provides a code division multiple access communication method. [0004] The code division multiple access communication method of the present invention, [0005] It is implemented traditionally based on BS-CDMA system, [0006] In the downlink of the system, the transmitting end of BS-CDMA transmits the data to be tran...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H04L27/26H04L5/00H04B1/7097
Inventor 陈晓华刘喜庆林凡孟维晓
Owner HARBIN INST OF TECH
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