M.Eng. in progress
An Inverse Multiplexing Scheme for IS-95 CDMA Systems
Mazda Salamania
Abstract

This thesis studies the feasibility of transmitting low data rate video signals over Code Division Multiple Access (CDMA) wireless channels.  We are investigating making minor changes to the IS-95 standard to allow for accommodating higher data rates, up to  8*9.6 = 76.8 kbps.  The video signals are compressed according to the H.263 standard but we allow for Variable Bit Rate (VBR) mode where data rate flutuates from frame to frame.

The specific scheme advocated by this thesis is an inverse multiplexing scheme.  Each video user acts as 8 IS-95 connections.  8 Walsh codes are assigned to the call and the remote terminal will have 8 time shifts of the long code.  The thesis investigates the feasibility of this scheme by a comprehensive simulation study that takes into account the effect of multipath delay spread.  The thesis also investigates the statistical multiplexing gain achieved by exploiting the VBR mode.