The IEEE 802.11n standard is the first wireless LAN standard based on MIMO-OFDM, a technique that significant range and rate relative to conventional wireless LAN. This chapter describes the main features of the 802.11n standard including packet structures, preamble formats, and coding aspects. Performance results show that net user throughputs over 100 Mbps are achievable, which is about four times larger than the maximum achievable throughput using IEEE 802.11a/g. For the same throughput, MIMO-OFDM achieves a range that is about 3 times larger than non-MIMO systems.

Introduction

The appetite for higher data rate continues as consumer demand for bandwidth hungry applications like gaming, streaming audio and video grows. Advancement in handset processors and further integration of technologies like higher mega-pixel cameras into handsets, create a never ending need for more bandwidth consuming applications at longer ranges and more efficient utilization of the limited spectrum available to Network Operators. 3G technology falls short in meeting this demand, while coverage is often worse than what customers are used to from 2.5G networks.

On the other hand, wireless LAN, the technology initially expected to provide only limited range and bandwidth has come a long way. Since the introduction of proprietary WLAN products in 1990 and the adoption of the first IEEE 802.11 standard in 1997, maximum data rates have made an impressive growth that is depicted in Figure 8.1.