Wireless communication for mobile terminals has been a high performance computing challenge. It requires almost super computer performance while consuming very little power. This requirement is being made even more challenging with the move to Fourth Generation (4G) wireless communication. It is projected that by 2010, 4G will be available with data rates from 100Mbps to 1Gbps. These data rates are orders of magnitude greater than current 3G technology and, consequently, will require orders of magnitude more computation power. Leading forerunners for this technology are protocols like 802.16e (mobile WiMAX) and 3GPP LTE. This paper presents an analysis of the major algorithms that comprise these 4G technologies and describes their computational characteristics. We identify the major bottlenecks that need to be overcome in order to meet the requirements of this new technology. In particular, we show that technology scaling alone of current Software Defined Radio architectures will not be able to meet these requirements. Finally, we will discuss techniques that may make it possible to meet the power/performance requirements without giving up programmability.