The Low Power Research of Adaptive Receiver of OFDM Digital Base-band
|School||Huazhong University of Science and Technology|
|Course||Microelectronics and Solid State Electronics|
|Keywords||OFDM Low power consumption Channel estimation Viterbi decoding|
With the growing number of wireless devices into life, the growing demand for multimedia services. Send multimedia services requires a certain bandwidth guarantee, but traditional wireless networks can not support multimedia services. OFDM modulation technology, with its high spectral efficiency and anti-jamming capability, to become a key technology in the future of mobile communications. 4G standard will provide higher transmission quality as the underlying modulation technique. Commonly used as a hand-held wireless devices, the battery-powered, power consumption is the key to its success, low power OFDM digital baseband receiving end of the study, the optimized design of high-power part. Paper first analysis of the basic structure of the OFDM digital baseband receiving end of and power consumption proportion, analysis shows that the channel estimator and the channel decoding device (the Viterbi decoding) occupy the entire wireless transceiver digital baseband power consumption of 70% to 80%, and therefore , to optimize the design of the two parts, will greatly reduce the power consumption of the handheld terminal. This paper analyzes the the mainstream several channel estimation algorithms, and low complexity channel estimation algorithm research. The algorithm proposed a combined pilot and training sequence for channel estimation. Simplified re-derivation of the state space equation of the Kalman filter algorithm. By Matlab7.0 system modeling and simulation results show that the proposed algorithm has low complexity, and performance in a mobile environment is superior to the traditional algorithm. Secondly, the paper is used in the Viterbi decoding method for channel decoding of the Viterbi decoding algorithm in the different coding rate and modulation scheme (BPSK (1/2, 3/4), QPSK (1/2, 3/4), 16QAM (1/2, 3/4), 64QAM (2/3, 3/4)) under conducted traceback depth vs performance of the simulation, an adaptive Viterbi decoder, through the design reconfigurable survivor path storage management unit (SMU), the decoder can be based on different modulation adaptively select backtracking depth branch metric unit (BMU) in the Viterbi algorithm, and reduced by simplifying branch metric computation and processing - than - Select unit ( ACSU) complexity. Traditional algorithm analysis more literature and hardware less attention, especially in the channel estimator. In this paper, the channel estimation and Viterbi decoding hardware implementation area and power consumption analysis of FPGA tool ISE and Designer Compiler. The experimental results show that they are not only in theory, high performance, and also reached on the realization of the purpose of the low-power.