Study on Spread Spectrum Packet Communications

扩频分组通信研究

• 批准号: 05805034
• 负责人: TAKAHATA Fumio
• 金额: $ 1.22万
• 依托单位: Waseda University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05805034/
• 关键词: Spread Spectrum; Packet Communications; ALOHA System; Direct Sequence; Chirp; Carrier Recovery; Symbol Timing Recovery; Throughtput; 一括復調方式; 熱雑音; フェージング

A spread ALOHA system using a unified spread spectrum code is discussed in terms of its performance, design and transmission efficiency. The system is outlined and then the bit error performance under two conditions is derived by a theoretical analysis and an approximate method. The comparison it with the results obtained by means of computer simulation indicates that the theoretical results coincide perfectly with the simulated ones and that the approximayte results coincide with the simulated results in the low E_b/N_0 range. A demondulator is designed focussing on symbol timing recovery and carrier recovery. It is proposed that the provision of a short preamble enables to apply a synchronous cyclic addition to these recoveries. It is concluded as a result of performance evaluation concerming symbol timing detection and carrier offset estimation that the proposed scheme improves the performance remarkably. The transmission efficiency obtained in the spread ALOHA system is derived for … More three cases. Comparing quantitatively the transmission efficiency in the first case with that of the conventional slotted ALOHA system under the condition at the same frequency bandwidth, it is concluded that the spread ALOHA system gives a good performance with the lower transmitting power compared with that of the slotted ALOHA system. As for the other two cases, the system using a unified spread spectrum code is compared with that using different spread spectrum codes in terms of transmission efficiency and it becomes obvious that the former system provides better performance for the long packet length than the latter one. Finally it is proposed to realize a spread-ALOHA system by using a chirp signal. Correlation process using the chirp matched filter is theoretically described at first and signal processings to be performed in the receiving side are clarified, in particular focussing on the block demodulator. The quantitative evaluation under various conditions is discussed concerning bit error rate performance obtained by means of computer simulation. Less

本文讨论了采用统一扩频码的扩频ALOHA系统的性能、设计和传输效率。首先对系统进行了概述，然后通过理论分析和近似方法推导了两种情况下的误码性能。与计算机模拟结果的比较表明，在低E_B/N_0范围内，理论结果与模拟结果完全吻合，近似结果与模拟结果吻合较好。设计了一个着重于符号定时恢复和载波恢复的解调器。建议提供短前导码使得能够将同步循环加法应用于这些恢复。对符号定时检测和载波偏移估计的性能评估结果表明，该方案显著提高了系统的性能。在扩展ALOHA系统中获得的传输效率被导出为： ...更多信息 三个案子。在相同的频带宽度条件下，对第一种情况与传统的时隙ALOHA系统的传输效率进行了定量比较，结果表明，与时隙ALOHA系统相比，扩频ALOHA系统具有较低的发射功率，但性能较好。对于另外两种情况，就传输效率而言，将使用统一扩频码的系统与使用不同扩频码的系统进行比较，显然，对于长分组长度，前一种系统比后一种系统提供更好的性能。最后提出了利用线性调频信号实现扩频ALOHA系统。首先从理论上描述了使用线性调频匹配滤波器的相关处理，并阐明了在接收侧要执行的信号处理，特别是集中在块解调器上。通过计算机仿真获得了误比特率性能，讨论了各种条件下的定量评估。少

项目成果

榎本大: "スプレッドアロハ方式へのチャープの適用" 電子情報通信学会論文誌(B-II). J76-B-II,11. 864-871 (1993)

Dai Enomoto：“Chirp 传播 Aloha 方法的应用”，电子、信息和通信工程师学会汇刊 (B-II)，11 (1993)。

榎本大、高畑文雄: "スプレッドアロハ方式へのチャープの適用" 電子情報通信学会論文誌. J76-B-II. 864-871 (1993)

Dai Enomoto、Fumio Takahata：“线性调频脉冲传播 Aloha 方法的应用”，电子、信息和通信工程师协会学报 J76-B-II 864-871（1993 年）。

吉田崇: "直接拡散スプレッド・アロハ方式における多重パケット検出について" 電子情報通信学会研究技術報告(衛星通信研究会). SAT94-13. 37-42 (1994)

Takashi Yoshida：“直接传播 Aloha 方法中的多数据包检测”IEICE 研究和技术报告（卫星通信研究组）。

笹森文仁: "同一の拡散符号を用いたスプレッドアロハ方式の伝送効率" 電子情報通信学会論文誌(B-II). J77-B-II,11. 726-732 (1994)

Fumihito Sasamori：“使用相同扩频码的扩频 Aloha 方法的传输效率”，电子、信息和通信工程师学会汇刊 (B-II)，11 (1994)。

Tohru KIKUTA,Takashi YOSHIDA,Kazuhiro HORIKOSHI and Fumio TAKAHATA: ""Comparison of Throughput Characterisitics in Spread ALOHA System using Unified Spread Spectrum Code"" 1995 Spring Natl.Conv.Rec.IEICE. B-238. (1995)

Tohru KIKUTA、Takashi YOSHIDA、Kazuhiro HORIKOSHI 和 Fumio TAKAHATA：“使用统一扩频代码的扩频 ALOHA 系统中的吞吐量特性比较”1995 年春季 Natl.Conv.Rec.IEICE。