Core technology and analysis of 802.11N

The new generation of mobile communications (Beyond3G/4G) is able to provide a data transmission rate up to 100Mb/s or even higher and support the business from voice to multimedia. The date transmission rate may be dynamically adjusted according to the different rates demanded by such business. Another feature of the new generation of mobile communications is its low cost. Therefore, to realize the high rate and large capacity on such a limited spectrum resource needs a technology with super high spectrum efficiency. MIMO technology fully develops the space resources and realizes multiple sending and receiving by using multiple antennas, without the need for additional spectrum resources and antenna transmit power, the single path capacity can be multiplied. OFDM technology is one of the multi-carrier transmissions, its multi-carriers are orthogonal to each other, therefore, the spectrum resources may be efficiently used. The efficient combination of MIMO and OFDM has become the hot point of the next generation of mobile communications. This paper focuses on the key technology of MIMO-OFDM, such as single path estimation, space-time processing technology, error correction and coding technology, adaptive modulation technology, coding technology and so on. The paper discusses the issue how to improve the performance and capacity of the wireless network at the same time when the MIMO-OFDM system provides higher rate and bandwidth utilization ratio.