Spread spectrum communicatoion system and non-centre wireless network for implementing CDMA by single different phase sequence of spread spectrum code

Abstract

This invention discloses a spread spectrum communication system and a centerless wireless network applying different phase sequences of a single spread spectrum code to realize CDMA. Said system includes a satellite receive clock pick-up unit, a clock synchronous unit, a control time-slot generation unit, a match unit a related multipath selection unit, a demodulation unit, a control process unit, a PN code set generator, a code multipath selection unit, a spread spectrum modulation unit and a duplexer, among which, the clock receive unit receives wireless signals for the system, and picks up clocks for the system, the clock synchronous unit generates code slice clock pulses synchronized to the data clock, the match receive unit receives wireless signals to generate multipath matched signals, the related multipath selection unit selects related values in an assigned time slot to be output to the demodulation unit, which finishes the demodulation of the information carried by related peaks, the control unit fetches the related data values in the assigned time slots to deal with data in a period and judge the pulse levels of related peaks and selects suitable phase sequences as the spread spectrum codes for emit signals based on the channel used situation or selects phase sequence as the local spread spectrum code used in the reception.

Description

technical field [0001] The invention relates to a spread-spectrum communication system that uses a code set composed of different phase sequences of a single spread-spectrum code to realize code division multiple access. This spread-spectrum communication system can be applied to wireless networks, and is especially suitable for multiple mobile A wireless mobile communication network composed of nodes. Background technique [0002] There are two types of wireless networks using spread spectrum technology: one is a wireless network with a center, such as a CDMA mobile communication system, each mobile station is responsible for the dynamic allocation of spread spectrum codes (that is, channel allocation) by the base station, even if two mobile stations In a cell, the communication between them must also be forwarded by the base station; the other type is a wireless network without a center, such as a wireless ad hoc network (wireless Ad Hoc network) and a wireless sensor netw...

AI Technical Summary

Problems solved by technology

As mentioned earlier, this is difficult to implement in practice

[0015] (2) Due to the mobility of decentralized wireless networks, collisions between public channels and data channels are still inevitable

[0016] (3) The selection of the channel for sending data is selected by the source node without referring to the status of each channel in the channel state table of the destination node, that is, if the channel selected by the source node is busy at the destination node, it will inevitably lead to a connection error. Failed to enter

[0017] (4) The problem of hidden terminals and exposed terminals has not yet been solved

[0018] (5) Does not have the function of real-time monitoring channel status

If multi-code spread spectrum code division technology is used to realize multiple access channels, due to no central control, each mobile node cannot know the channel usage status of the entire network, so it is impossible to realize the dynamic code allocation (DCA) mechanism, which greatly limits the spread Application of frequency technology in wireless network

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