Research On Some Key Technologies Of Wideband WPAN Based On High-rate Frequency-hopping Technology

Wideband tendency of personal communications has become one of hot issues in current wireless communication networks. How to provide wideband high-rate applications with limited frequency resource for personal communications has great significances. To satisfy the demand, some key technologies of wideband WPAN based on high-rate frequency hopping technology are studied thoroughly, mainly including FH-CDMA, parallel transferring technology by multiple links, channel coding methods of improving error-correcting capability, and etc.With improving frequency bands of WPAN based on high-rate frequency-hopping technology as the general objective, a high-rate frequency hopping system with multi-link parallel transferring is presented, whose data rate and system frequency band are both improved by multi-link parallel transferring technology. Because parallel data transfer technology by multiple links requires several same systems co-existing, anti-interference problems have to be considered to improve system capacity. With BCH codes as an example, a novel and simple table-search decoding algorithm is put forward to extend the error-correcting capability of some BCH codes. After that, interleaving technology is applied to BCH codes so that the anti-interference capability of the whole system can be improved.Firstly, Bluetooth frequency hopping algorithm is implemented and its frequency hopping characteristics are analyzed. On the basis of simulation, Bluetooth's self-interference characteristic is elaborated on. And then two formulas of numbers of co-existing Piconet under some specific QoS are deduced. The deduction and simulation lay a theoretical foundation for the presented multi-link parallel transferring system.Secondly, according to the previous theoretical deduction, a high-rate frequency hopping system with multi-link parallel transferring is given and implemented based on Bluetooth systems. The design principle, system model, module diagrams and concrete implementations of the designed system are then demonstrated with the emphasis on its advantages and creativeness. File transfer taken for example, performances of data rate and throughput of the implemented system with Bluetooth are analyzed, and the feasibility of the designed system is proved. Thus the contradiction between frequency resource and wideband high-rate applications can be reasonably settled down.Thirdly, multi-link scheduling algorithms and flow control algorithms concerned with the presented multi-link parallel transferring technology are studied. After several kinds of current algorithms are summed up, the algorithms used in the implemented system and their performances are analyzed. And to show the meaning of multi-link parallel transferring technology, its applications under WPAN environment are further extended.Finally, in order to improve anti-interference capability of the high-rate frequencyhopping system with multi-link parallel transferring, error-control coding theory is also researched with improving the error-correcting capability of some BCH codes. A new and simple decoding algorithm for BCH codes is brought forth to improve error-correcting capability of some BCH codes, which is called table-search decoding. All the error patterns with weights equal to t+1 and that BCH (n, k, t) codes can correct are found out with the decoding algorithm. Then these error patterns and those whose weights are less than t+1 are ordered according to their corresponding syndrome values. The ordered error patterns are stored in hardware devices so that decoding can be realized by searching the relation tables. The following results are shown through simulations. To BCH codes, when the code bits and information bits are the same, this decoding method can correct one more error bits than usual decoding methods. And moreover, the decoding circuits are comparatively simpler and the decoding speeds are faster. This decoding method of improving the error-correcting capability is applicable to all binary linear cyclic codes. After this BCH decoding algorithm is applied, interleaving technology is then practiced to improve anti-interference capability of the wideband WPAN system in a degree. And thus the system capacity can also be extended.