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Quick frequency hopping and expanding communication method based on orthogonal frequency division duplexing

An orthogonal frequency division and spread spectrum communication technology, applied in the field of communication, can solve the problems of limited number of users and frequency hopping frequency points in OFDMA system, and achieve the effect of strong anti-interference ability and high data transmission rate

Inactive Publication Date: 2007-01-24
TSINGHUA UNIV
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Problems solved by technology

Since the above methods only use subcarrier frequency hopping, there are problems such as the limited number of frequency hopping points and the limited number of users in the corresponding OFDMA system, so it is necessary to combine the ordinary frequency hopping system and the spread spectrum system for comprehensive design and optimization

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  • Quick frequency hopping and expanding communication method based on orthogonal frequency division duplexing
  • Quick frequency hopping and expanding communication method based on orthogonal frequency division duplexing
  • Quick frequency hopping and expanding communication method based on orthogonal frequency division duplexing

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Embodiment Construction

[0034] The present invention proposes a fast jump-spread spectrum communication method based on OFDM, wherein the signal transmission process block diagram is as follows figure 1 As shown, first, the transmitting end generates spreading sequences, subcarrier allocation signals and frequency hopping sequences according to user requirements; performs direct sequence spreading or encoding processing on user data; performs symbol modulation on the processed data to generate modulated signals; According to the subcarrier allocation signal, the above modulated signal is allocated to each subcarrier of the user communication signal, and a cyclic prefix is ​​added; the communication signal is converted from digital to analog to obtain an analog signal; according to the frequency hopping sequence, the frequency synthesizer at the sending end A carrier frequency is generated and the aforementioned analog signal is modulated onto this carrier frequency. The block diagram of the signal re...

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Abstract

This invention relates to a quick hop-expansion communication method based on OFDM, in which, an transmission end generates frequency expansion sequence, sub-carrier distribution signals and FH sequences according to user request, carries out direct sequence frequency expansion or code process then to modulate symbols then distributes the modulated signals to the sub-carriers of communication signals of users according to the sub-carrier distribution signals to be added with circulation prefix for D / A conversion then modulates the received analog signal to the carrier frequency generated according to the FH sequence, the receiving end receives signals then carries out de-FH, A / D conversion and removing the circulation prefix and de-modulates the modulation signals on the sub-carrier of the user communication signals to be output in series to get the user data after the symbol is de-modulated, de-coding or de-FH.

Description

technical field [0001] The invention relates to a fast jump-spread spectrum communication method based on orthogonal frequency division multiplexing, which belongs to the technical field of communication. Background technique [0002] In order to increase the data transmission rate, the transmission mode of Orthogonal Frequency Division Multiplexing (hereinafter referred to as OFDM) is adopted; in order to improve the user capacity and reduce the interference between users, the "hop spread spectrum" scheme combining direct sequence spread spectrum and frequency hopping is adopted ; In order to effectively resist the time-selective fading caused by high-speed mobile, a two-level frequency hopping scheme of OFDM symbols and subcarriers is adopted, which can also effectively resist blocking interference. [0003] The OFDM transmission method sends serial data in parallel on several sub-carriers, which greatly improves the data transmission rate. Since the data transmission rat...

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H04L27/32H04B1/713H04J11/00
Inventor 张超王有政陆建华
Owner TSINGHUA UNIV
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