The Apply Study Of OFDM Used In Mobile Communication System

Data transmission in mobile channel with high speed and reliability is required in future mobile communication system. The 4th mobile communication system is expected to provide high-quality broadband services using the minimum possible resources (power, bandwidth, complexity). Toward this end, an appropriate transmission technique that matches the mobile channel characteristics is required. Taking many uncertain factors in mobile communication channel into account, OFDM (orthogonal frequency-division multiplexing) is one of the promising techniques that meet such requirements with reasonable complexity. OFDM is one of multi-carrier digital modulation techniques, in which a single high data rate data stream is transmitted using a number of lower data rate sub carriers, it has many properties, such as robustness to multi-path fading, high data rate transmission capability with high bandwidth efficiency, and so on.Base on the study of mobile communication channel characteristics, this thesis gives an analysis on the existing problems, such as multi-path fading and Doppler frequency shift, and proposes a solution: Implanting the OFDM technique in modulator. In this thesis, detailed design architecture is given, together with a simulation analysis of the OFDM mobile communication system. With consider of cost and performance, the thesis gives a design project of OFDM mobile communication system. The thesis makes and works as follows:At first, established the mobile channel model, through the analysis of the mobile channel characteristics;The second, proved the advantage of OFDM througth comparing several parallel technologies, and implanting the OFDM technique in the mobile communication system modulator;Then, this thesis gived the baseband transmission architecture of OFDM mobile communication system and established the model of OFDM mobile communication system.At last, the thesis gives a brief introduction of the design of the hardware platform for the wireless communication system as well as the data transmission flaw.