Hardware Implemention Of The Multicarrier Tranceiver In GMC-TDD-xDMA DEMO System And Development Of USB2.0 Interface Card

In recent years, mobile communication has developed rapidly in worldwide. The 3rd generation mobile communications system has been gradually applied for business, however, it will still not meet users' greatly increased needs in near future. Therefore, it is necessary to work with a high-speed mobile wireless communications technology, which can support unsymmetry service, wide-band multimedia service, internet service and integrated service in further. According to the research targets of next generation cellular mobile system as a portion of 863 Future Project, as well as the evolution of research around the world, National Communication Research Laboratory (NCRL) of Southeast University is developing Generalized Multi-Carrier Time Division Duplex x-Division Multiple Access (GMC-TDD-xDMA) cellular mobile transceiver technique, in order to reach the goal of high efficient packet data transceiver with peak data rate not less than 20Mbps in the first phase .As a consequence, according to principles of EMC and SI(signal intergrity), this thesis intends to carry out the research on the hardware design of multi-carrier tranceiver and the USB interface. The demo system herein consists of three parts: base band transmitting board, baseband receiving boards and MPU board. Baseband transmiting board is named as TX_DMS board, which includes the baseband processing of 12 single-carriers, multi-carrier synthesis filtering, and D/A converter. Baseband receiving boards comprise RX_AMS board and RX_SP board, the former including 4 groups of A/D converters corresponding to 4 receiveing antennas, 4 receiving multi-carrier analysis filter banks and synchronization modules. RX_AMS board receives 4 routes of analog base band signals from RF receiving circuit, realizes analog-digital converters, multi-carrier synthesis filter banks and timing synchronization, and transfers the generated synchronized sub-carrier digital base band signals to RX_SP board, which realizes all sub-carriers digital base band process. MPU board is responsible for system control, signaling process, multi-media service accessing and other control and management relating to the system. USB interface board undertakes system traffic transfer, while the multi-media traffic based on IP packet of external terminal is accessed into the wireless communications system through USB interface.The author has attended the design, layout, test and debugging of the RX_AMS board and the TX_DMS board, and is mainly responsible for the design and debugging of such modules as the circuit of ADC and DAC, the LVDC interface and FPGA downloading circuit. The author has implemented the design and debugging of the USB2.0 interface. Also, he takes part in the system debug of the baseband system and the joint of the baseband system and the RF module.This thesis presents in detail the arrangements of TX_DMS and RX_AMS, power module, decouple of power, clock distribution, FPGA downloading circuit, digital-analog/analog-digital converters, LVDS transmission of backplane, and USB interface. This thesis deals with signal integrity design for the hardware realization, and elaborates the design principles of the PCBs as well. In addition, the corresponding testing program and test data are also provided in this dissertation. The number of valid bits is 9 for tone signal in test of DAC-ADC loop with the sample rate 23.04 MHz. The working frequency of LVDS is more than 90MHz and the one-way bit rate of this USB2.0 interface board has reached 200Mbps. The design of the circuit has achieved the predicted purpose and can met the requirement of the system.