802.11n & 802.16e 雙模多輸入多輸出正交分頻多工基頻接收機之設計與實作

Abstract

The increasing reliance on the Internet in everyday life has led to more demand for roaming Internet services. The proposed dual mode wireless receiver fills this gap by increasing the coverage of the service area. By implementing both 802.16e and 802.11n, Internet access is made available in indoor and outdoor environments. The purpose of this thesis is to implement a dual mode 2x2 MIMO OFDM & OFDMA with shared hardware resources. This dual mode receiver should function well in both static channels and mobile channels. It follows the specification requirement of EWC HT PHY V1.27 and IEEE 802.16e-2005, and proposes a PHY baseband simulation model to meet the specifications. The transmitter and channel models are modeled in software. The receiver uses software to model the hardware, and a fixed-point design is implemented as well. The receiver is divided into Synchronization, Tracking, and Equalization. Synchronization includes cell search, symbol boundary detection, fractional and integer CFO estimation and compensation. Tracking performs FFT, Joint Weighted Least Square Estimation, and residual CFO and SCO estimation and compensation. Equalization includes channel estimation and MIMO equalization. Effort was made to reuse hardware between Synchronization and Tracking. Additionally, Equalization supports both dynamic and static channel estimation. 2x2 MIMO STBC and VBLAST are supported as well. A low cost ICI cancellation hardware is also proposed. By adopting various channel models, including several nonlinear channel effects such as multipath Rayleigh fading, dynamic channel Doppler effect, carrier frequency offset, and sampling clock offset, the dual mode receiver has been shown to successfully recover the transmitted signal even in non-optimal environments.