tailieunhanh - WIMAX, New Developments 2011 Part 14

Tham khảo tài liệu 'wimax, new developments 2011 part 14', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 344 WIMAX New Developments architectures based on communication centric platforms. The WiMAX physical layer was ported on this platform. In WiMAX physical layer apart from the usual functions such as randomization forward error correction FEC interleaving and mapping to QPSK and QAM symbols the standard also specifies optional multiple antenna techniques. This includes space time coding STC beam forming using adaptive antennas schemes and multiple input multiple output MIMO techniques which achieve higher data rates. The OFDM modulation demodulation is usually implemented by performing FFT and inverse FFT on the data signal. Consequently FFT and Viterbi are considered in this work are modelled in SystemC as hardware accelerators which are compute intensive modules in WiMAX receiver computing chain. The WiMAX application runs as a software core on the ARM7 ARM 1999 processor. A Reconfigurable FFT IP and a Viterbi decoder as hardware accelerators are integrated into the WiMAX chain to validate their performance by co-simulating modules from different levels of abstraction. 2. Related Work In Rissa et al. 2002 a modelling technique for reconfigurable systems is proposed based on OCAPI-xl a modelling language similar to SystemC. A set of processes is used to model a run time reconfigurable process which is supervised by a HardWare Scheduler HWS . In Noguera Badia 2003 a modelling methodology for reconfigurable architectures based on discrete event systems is presented. In an object-oriented manner discrete event classes and objects form a reconfigurable system which introduces all necessary modelling capabilities to cover run time reconfiguration. In Enzler et al. 2003 a co-simulation environment is unveiled enabling performance estimation for a dedicated architecture which couples a CPU together with a coarse grained multi-context reconfigurable unit RU . Performance evaluation is based on a cycle-accurate simulation including execution and reconfiguration