Modeling of DC-OFDM UWB physical layer in Matlab and design of demapping module with high diversity gain

Abstract: Due to the development of semiconductor and digital communication technology, amounts of wireless communication technology have been presented recently. Among those techniques, Ultra Wide Band (UWB) technology is an outstanding short distance wireless communication technology. With the characters of fast speed, low power consumption and high security, it is a perfect communication technology for Wireless Personal Area Network (WPAN). According to the application environments of the UWB techniques, the International Standard Organization (ISO) has passed the European Computer Manufacturers Association (ECMA) 368 standard to be the UWB physical layer standard. Because of the wide bandwidth and frequency spectrum characters of UWB system, every country drafts their own UWB standards according to their own situations. For the system implementation, modeling is the first important part. The accuracy and practicality of model are in high accordance with the hardware implementation. The thesis main work is to set up the Matlab model of the Dual Carriers-Orthogonal Frequency Division Multiplexing (DC-OFDM) UWB physical layer system which is designed by China Electronics Standard Institute (CESI). In the modeling course, the thesis analyzes the differences between hardware implementation and algorithm simulation, and use fix-pointed to quantize the inputs and outputs of the modules, so that the model is more practical. In the system simulation, by changing the Sample Frequency Offset (SFO), Carrier Frequency Offset (CFO), Noise and Multi-path interferences, the model is verified and sets up the stable foundation for the hardware design. What’s more, in order to make full use of the wide band, this thesis uses diversity demapping method for the Dual Carrier Modulation. According to the biggest combine ratio diversity technique and estimated channel diversity technique, the biggest diversity gain can be got, and the performance is improved by 1.5dB. Considering the diversity demapping algorithm, in the hardware implementation, mapping and demapping modules are designed for hardware reuse. This can not only decrease the area and the power, but also be compatible with ECMA368 and DC-OFDM standard