Research On The Key Technologies Of Universal Signal Source Design In Wireless Communication

At present, TD-SCDMA and other3G technologies have been applied commercially, TD-LTE and other next-generation technologies have been involved into the testing stage. How to provide high-performance and low-cost devices are one of the key issues. Meanwhile a large number of vector signal sources are needed for wireless communications equipment in developing, testing and optimizing process. However the prices of these RF signal sources are quite expensive and they also exhibit some limitations. Therefore, studies of the universal signal generator design have important application value in wireless communications.In the developly process of communication technology, there are many standards, such as TD-SCDMA, WCDMA and CDMA2000in3G. Generally different standards lead to different signal sources, even if there are certain compatibilities yet limited. Moreover, a vector signal source compatible with a variety of standards will be more expensive. Meanwhile, before the end of standardization, it is usually difficult to use existing signal sources for direct replacement.According to the above description, this thesis explored the universal signal source design method in wireless communication, which has three key issues. Firstly, the flexibly framing technology, i.e. a unified framing module, is able to generate baseband frame signals of multiple communication standards by different parameter configurations; secondly, the uplink/downlink channels simulation technology closing to the real-world environment; finallly, the interface designs between the hardware signal source and software design, as well as the generation technology of the controlled RF signal. Therefore, this thesis designed a flexibility framer module and uplink/downlink channel modules in Agilent ADS software, to generate the baseband signal, and then the traditional vector signal generator is controlled through GPIB interface to generate the physical signal. Theoretically, any radio signal can be generated in this way, i.e. the universal property. Certainly, the RF performance of the generated signal requires the support of real-world signal sources.In order to realize the key technologies aforementioned, this thesis investigates the framing module with flexible parameters in ADS, and studies the geometrical and statistical characteristic of uplink/downlink channel modules based on MATLAB. Moreover the autoregressive filter technology is exploied to model the fading channel with an arbitrary power spectrum density, and its modular implementation in ADS is also introduced. Finally, a demonstrating design process is presented for TD-SCDMA signals, and the output signal confirmed the effectiveness of the proposed method...