SPECTRAL EFFICIENCY IMPROVEMENT IN W-CDMA USING DYNAMIC ASSIGNMENT OF OVSF CODES

Abstract

The dissertation presents optimal dynamic code assignment (DCA) scheme using orthogonal variable spreading factor (OVSF) codes. The objective of the dynamic code assignment is to enhance statistical multiplexing and spectral efficiency of W-CDMA systems supporting variable user data rates. Our scheme is optimal in the sense that it minimizes the number of OVSF codes that must be reassigned to support a new call. By admitting the calls that would normally be blocked without code reassignments, the spectral efficiency of the system is also maximized. We also discuss various signaling techniques of implementing our proposed DCA scheme in third generation wideband CDMA systems.