Experimental Investigation of User Identification and Delay Estimation for Asynchronous CDMA-Based UOWC
- Resource Type
- Conference
- Authors
- Chen, Xiaorui; Liu, Weijie; Huang, Nuo; Xu, Zhengyuan
- Source
- 2023 IEEE 11th International Conference on Information, Communication and Networks (ICICN) Information, Communication and Networks (ICICN), 2023 IEEE 11th International Conference on. :359-363 Aug, 2023
- Subject
- Communication, Networking and Broadcast Technologies
Photonics and Electrooptics
Wireless communication
Integrated optics
Codes
Delay estimation
Interference
Multiple access interference
Multiaccess communication
Asynchronous CDMA
UOWC
user identification
delay estimation
multiple access interference
- Language
User asynchrony and near-far problem are two pivotal issues in the underwater optical wireless communication (UOWC) multiple access system. In this paper, asynchronous code division multiple access (CDMA) is introduced to the UOWC system. A subspace-based user identification and delay estimation algorithm is proposed to identify active users and estimate their delays, which requires only prior knowledge of spreading codes of all registered users. An underwater testbench facilitating three-user access is established to further demonstrate the feasibility of the proposed algorithm. Experimental results show that active users with large signal-to-noise ratio can be accurately identified given an appropriate threshold, and the signals of active users can be successfully acquired in the presence of multiple access interference (MAI).