Time Slot Allocation Schemes for Multihop TDD-CDMA Cellular System

Abstract

In UMTS terrestrial radio access (UTRA) standard, each frame consists of 15 TSs for TDD-CDMA system. Any MS can be allocated to any TS for either uplink or downlink transmission. The time slot allocation scheme within these 15 TSs gives the system the freedom of adapting the channel environment. In this paper, we propose and study multihop dynamic time slot allocation schemes, namely dynamic switching point with multihop (DSPM) and maximum interference first (MIF), for TDD-CDMA system. Compared to slot allocation schemes without multihop technique, it is shown that our proposed schemes can improve both the data rate for single user and the overall throughput for the whole system. In addition, we also study the distribution of data transmission speed to demonstrate the effectiveness of each slot allocation scheme clearly.