CDMA-Enforced Time Division Multiplex Access

• 来源期刊: 中国电子杂志（英文版）
• 学科: 工学
• 关键词: MAC (Multiple addess code) pro-tocol contention TDMA PRMA (Packet reservationmultiple access) CE-TDMA.
• 年，卷（期）: 2001,（1）
• 页码范围: 61-64
• 页数: 4页
• 分类号: TN
• 语种: 英文

摘要

In this paper,we present a new MACprotocol called CDMA-Enforced Time Division Mul-tiplex Access (CE-TDMA) that can efficiently sharethe radio channel from dispersed multimedia termi-nals to a base station.The protocol multiplexes dif-ferent users in a time division manner in both uplinkand downlink channels,and dynamically adjusts thetimeslot allocation using the information gathered inCDMA channel.The novelty of this protocol is to useCDMA and TDMA channels in a superposition wayto solve the multiple access contention problems whileretaining high spectrum efficiency.Under the con-trol of the base station,neither random access controlnor access contention exists in both uplink and down-link payload channels,so that high throughput can beachieved even under heavy load level.With the help ofthe CDMA access channel,guard time between uplinktimeslots,which has to be set large enough to avoidthe overlapping of the adjacent timeslots assigned todifferent mobile users,is also dramatically reduced.Analysis and simulation show that,after eliminatingthe contention and reducing the guard time in theuplink channel,system performance can be improvedgreatly.