Link Adaptation Techniques And The Implementation Of Key Modules

In wireless communication networks, the performance of wireless links is severely degraded due to multi-path propagation effect and time variance characteristics. In addition, with the surge of mobile communication users, the scarcity of frequency spectrum seriously limits the development of wireless communication. Link adaptation is the key technology of solving these problems. OFDM (Orthogonal Frequency Division Multiplexing) has the strongpoint of effectively combating multi-path effect and high frequency spectrum using efficiency. As one of link adaptation technologies, OFDM dynamic resource allocation technology attracts the attention of researchers.In this thesis, the basic theory of link adaptation and the key technologies are introduced. Link adaptation, such as Adaptive Modulation Coding, Power Control, Automatic Repeat Request, OFDM dynamic resource allocation technology and joint source channel coding technology etc, are described. In order to investigate OFDM dynamic resource allocation technology, an OFDM baseline system based on Digital Signal Processor is introduced. This system is the hardware platform of investigating OFDM dynamic resource allocation technology. The hardware design of DSP system board and FIFO (First-in First-out) board are introduced emphatically. Furthermore, the debugging of OFDM baseline software of DVB-T 2K model is introduced, and some C language programs of channel coding in this system are optimized. The interface programs from DSP to DSP and FPGA are designed. The interfaces of hardware system are debugged. At last, multi-DSPs parallel processing technology is introduced.