可提升直序式超寬頻通訊系統傳輸量之適應性位元率切換策略研究

Enhancing Data Throughput of DS-UWB System Using Adaptive Data Rate Switching Scheme

彭國華(Kuo-Hua Peng)

指導教授 ： 譚旦旭

國立臺北科技大學/機電學院/電機工程系所/碩士(2005年)

https://doi.org/10.6841/NTUT.2005.00218

摘要

直序式超寬頻（DS-UWB）標準訂定8種位元率傳輸模式以滿足不同情況下的需求，由於缺乏一種能隨著通道變化而自動切換至最合適位元率傳輸模式的機制，使得系統無法達到最大資料傳輸量，如此將壓抑DSUWB系統的資料傳輸量，進而影響系統效能。
為了克服上述問題，本研究根據DS-UWB不同的位元率傳輸模式（包括110、220、330以及660 Mbps）及自動重複請求（ARQ）的『ARQN』統計量，提出可應用於DS-UWB環境的適應性位元率切換策略機制。
本研究在CM1∼CM4 通道環境下，利用stop-and-wait ARQ 來探討DS-UWB 系統的資料傳輸量，由於目前UWB通訊系統仍未明確定義最大容許延遲時間，因此本研究設定10 ms 作為臨界值，來提供高品質通訊服務。
實驗結果顯示本研究所提出的適應性機制可以有效估計通道狀態進而切換位元傳輸率，因此大幅提昇DS-UWB系統的資料傳輸量。

關鍵字

直序式超寬頻通訊（DS-UWB） ； 適應性策略 ； 自動重複請求（ARQ）

並列摘要

Though eight data rates have been presented by direct sequence ultra-wideband (DS-UWB) standard to satisfy various requirements, only one fixed data rate can be employed during the whole transmission period because the data rate switching mechanism is not supported yet. Therefore, the DS-UWB system will never achieve maximum data throughput since it cannot adapt the transmitting data rate to the dynamic channel situations. To overcome this difficulty, an adaptive data rate switching scheme based on the statistics of ARQN of the ARQ scheme is proposed to switch the data rates of 110 Mbps, 220 Mbps, 330 Mbps, and 660 Mbps.
A series of simulations is conducted over the UWB channels of CM1, CM2, CM3, and CM4 to explore the through improvement of DS-UWB with stop-and-wait ARQ by using the proposed switching scheme. Since the allowed delay time is not specified in the UWB system yet, the 10 ms delay time threshold is therefore specified to ensure high quality service.
Experimental results indicate that the proposed scheme can effectively switch the data rate by adaptively tracking the channel variations and thus significantly enhances system throughput.

並列關鍵字

DS-UWB ； Adaptive data rate switching scheme ； ARQ

參考文獻

UWB Standard

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