Optical orthogonal code-division multiple-access system .II. Multibits/sequence-period OOCDMA
Optical orthogonal code-division multiple-access system .II. Multibits/sequence-period OOCDMA
复制标题
光正交码分多址系统.II．
DOI：
10.1109/26.310619
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发表时间：
1994
影响因子：
8.3
通讯作者：
H. Kwon
中科院分区：
文献类型：
--
作者：
H. Kwon
关于这一部分，我见同上。第42卷，第7期，第2470页(1994)。在最近提出的光正交码分多址(OOCDMA)系统中，每个序列周期发送用户数据的一个比特，并且使用一个阈值来进行最终的比特判决。本文介绍了一种在一个序列周期内可以传输多个比特的系统，包括雪崩光电二极管的噪声、热噪声和干扰。通过利用OOCDMA码序列的正交特性并在最终判决中使用最大搜索(而不是阈值)而得到的该系统，在吞吐量方面是log/sub2/F倍，其中F是序列周期。例如，在接收激光功率为-56dBW时，误码率为4个数量级，F=1000个码片，一个序列中有10个标记，1比特/序列周期为30Mb/S数据速率，多比特/序列周期系统为270Mb/S数据速率的10个用户。在此基础上，对对数/次2/F比特/序列周期系统在接收端加硬限幅器的情况进行了精确的分析，并与未加硬限幅器的码片同步情况下的性能进行了比较。在对数/次2/F比特/序列周期OCCDMA系统中，使用硬限幅器的改进是显著的(而在第一部分中提出的一比特/序列周期OCCDMA系统中不是这样)。>；
For part I see ibid. vol.42, no.7, p.2470 (1994). In a recently proposed optical orthogonal code division multiple-access (OOCDMA) system, one bit of user's data is transmitted per sequence-period, and a threshold is employed for the final bit decision. In this paper, a system that can transmit multibits per sequence-period is introduced, and avalanche photodiode (APD) noise, thermal noise, and interference, are included. This system, derived by exploiting orthogonal properties of the OOCDMA code sequence and using a maximum search (instead of a threshold) in the final decision, is log/sub 2/ F times higher in throughput, where F is sequence-period. For example, four orders of magnitude are better in bit error probability at -56 dBW received laser power, with F=1000 chips, 10 "marks" in a sequence, and 10 users of 30 Mb/s data rate for one-bit/sequence-period and 270 Mb/s data rate for multibits/sequence-period system. Furthermore, an exact analysis is performed for the log/sub 2/F bits/sequence-period system with a hard-limiter placed before the receiver, and its performance is compared to the performance without hard-limiter, for the chip-synchronous case. The improvement from using a hard-limiter is significant in the log/sub 2/F bits/sequence-period OCCDMA system (while it is not in a one-bit/sequence-period OOCDMA system proposed in Part I). >