摘要
全球微波接入互操作性(WiMAX)是4G的核心技术,其物理层采用正交频分复用(OFDM)/正交频分多址(OFDMA)技术,帧同步是实现这一技术的关键。因此,对WiMAX物理层进行了Simulink建模仿真,同时基于IEEE 802.16d下行链路帧结构提出新的帧同步算法。该算法用长导频符号中的第1个OFDM符号进行粗同步来估计FFT窗的可能起始位置,然后用第2个OFDM符号进行细同步来确定FFT窗的起始位置。最后,将帧同步算法用嵌入式Matlab function模块嵌入WiMAX Simulink模型中。仿真结果表明,新算法在较低的信噪比或多径衰落环境下仍可产生脉冲型定时度量,较之传统算法定时估计更准确。
PHY （Physical Layer） of WiMAX（ Worldwide Interoperability for Microwave Access） which is one of 4G core technique adopts OFDM （Orthogonal Frequency Division Muhiplexing）/OFDMA（ Orthogonal Frequency Division Multiplexing Access）, while the frame synchronization is the key of OFDM implementation. A WiMAX system simulation model is achieved by Simulink and a new frame synchronization algorithm based on IEEE802. 16d downlink frame structure is proposed. Firstly, the proposed algorithm makes coarse synchronization with the first OFDM symbol in long preamble to identi- fy the probable start point of FFT window, and then makes fine synchronization with the second OFDM symbol in long preamble to identify the true start of OFDM window. In the end, the new algorithm is embedded into the WiMAX PHY model with the block embedded Matlab function. The results of the simulation show that the proposed algorithm can produce impulse-shaped timing metric under the low SNR （signal-to-noise ratio） or over multiple fading channel, and timing estimation is more accurate than conventional algorithms.
出处
《电视技术》
北大核心
2012年第3期99-102,共4页
Video Engineering
基金
内蒙古自治区自然科学基金项目(2010MS0910)
内蒙古科技大学创新基金项目(2010NC033)
