ow the improvements. Similar to previous chapters, the description of 3GPP LTE/LTE-Advanced technologies are also provided to enable the reader to compare and understand both technologies, by making analogies between the corresponding protocols and functional blocks. The description of the physical layer procedures and measurements has been divided into two parts, where the multiple access schemes, frame structure, subchannelization schemes, coding and modulation, as well as physical layer Mobile WiMAX. DOI: 10.1016/B978-0-12-374964-2.10009-8 Copyright © 2011 Elsevier Inc. All rights reserved. CHAPTER 9 The IEEE 802. 16m Physical Layer (Part I) Network Layer CS SAP Radio Resource Service Specific Control and Convergence Management Sublayer MAC SAP MAC Sublayer Security Sublayer PHY SAP Physical Layer Control Plane Data Plane FIGURE 9-1 Location of the physical layer in IEEE 802. 16m protocol stack synchronization and broadcast information, are described in this chapter, and other physical layer topics including control structure and multi-antenna techniques are treated in the Chapter 10. 9.1 OVERVIEW OF IEEE 802.16M PHYSICAL LAYER PROCESSING This section provides an overview of the physical layer processing in IEEE 802.16m. The processing steps and the associated control signaling are depicted in Figure 9-2. While the physical layer of the IEEE 802.16m is based on the IEEE 802.16-2009 standard, there are new or modified functional components that contribute to significantly increased performance of the IEEE 802.16m relative to the legacy standard. During the design of IEEE 802. 16m, an attempt was made to identify the shortcomings of the legacy standard and to replace the inefficient protocols with new or improved procedures. In some cases, such as frame structure, subchannelization and permutation, and control signaling, there have been great changes from the corresponding legacy frameworks which make the mixed- mode operation of the new and legacy systems more complex. However, extreme modifications were necess