Design And Implementation Of MIMO-OFDM Baseband Systems For IEEE802.11n

With the rapid development of wireless local area network (WLAN), especially for the release of IEEE802.11n standard, the implementation of the high-throughput system is no longer a problem, and this is due to MIMO and OFDM technology the standard uses. MIMO technology can greatly improve the throughput of the system without the increasing of the system bandwidth, while OFDM technology can enhance the ability to cope with intersymbol interference (ISI). Therefore, this paper combines MIMO technology with OFDM technology and a2*2MIMO-OFDM baseband system is designed and implemented.On the basis of the related theoretical knowledge of the MIMO and OFDM systems, MIMO technology is combined with OFDM technology by this paper and a basic system model is presented. This paper makes use of C language to design and achieve the function of each module on the MVC++6.0platform through the principles. The transmitter includes convolutional coding, interleaving, QAM modulation, IFFT operation, CSD, CP insertion and framing, and the receiver includes the module of synchronization, CP removal, FFT operation, channel estimation and equalization, QAM demodulation, de-interleaving and Viterbi decoding. We make use of2random binary bit streams to have a test for the whole baseband system so as to check whether the processing results of the system can meet the designed requirements. In order to ensure the system is reliable, the key modules of the system that includes synchronization, channel estimation and Viterbi decoding are tested individually and the results show that they all meet the basic requirements. The tested results of Viterbi decoding prove that the designed system in this paper has strong ability against bit errors.