Adaptive MMSE turbo equalization with high-order modulations and spatial diversity applied to underwater acoustic communications
نویسندگان
چکیده
This paper presents some results on adaptive minimum mean-square error (MMSE) turbo equalization obtained from underwater experiments in the Atlantic ocean. The performance gain is evaluated as a function of the number of hydrophones at the receiver side. Single-carrier transmission with high-order modulations is considered, at a coded bit rate as high as 24 kb/s on the underwater acoustic channel. The all-digital receiver performs timing recovery, equalization, interleaving and channel decoding.
منابع مشابه
Iterative Equalization and Decoding Scheme for Underwater Acoustic Coherent Communications
Digital communications through underwater acoustic (UWA) channels differ from those in other media, such as radio channels, due to the high temporal and spatial variability of the acoustic channel which make the available bandwidth of the channel limited and dependent on both range and frequency. In order to overcome disadvantage factors and maximize performance to conduct real-time information...
متن کاملOn the Practical Aspects of Joint Passive Phase Conjugation and Equalization Underwater Communication Systems
Underwater acoustic communication systems suffer from the channel impairments which results in time spreading of the transmitted signal. In underwater environment, multiple replicas of the transmitted signal are received at the receiver through different paths, which causes significant Inter-Symbol Interference (ISI). Decision Feedback Equalizers (DFE) was utilized to overcome this type of inte...
متن کاملTurbo-equalization for bandwidth-efficient digital communications over frequency-selective channels
This thesis deals with the problem of combining equalization with decoding for high data ratebandwidth-efficient transmissions over frequency-selective channels. Specifically, we focus on Turbo-Equalization which establishes an exchange of soft information between the equalizer and the decoderin an iterative manner. We first consider MAP turbo-equalizers which rely on trellis-based ...
متن کاملA Novel Receiver Algorithm for Coherent Underwater Acoustic Communications
In this paper, we proposed a novel receiver algorithm for coherent underwater acoustic communications. The proposed receiver is composed of three parts: (1) Doppler tracking and correction, (2) Time reversal channel estimation and combining, and (3) Joint iterative equalization and decoding (JIED). To reduce computational complexity and optimize the equalization algorithm, Time reversal (TR) ch...
متن کاملDesign and Simulation of a Secure and Robust Underwater Acoustic Communication System in the Persian Gulf
In recent years, underwater acoustic (UWA) communications have received much attention as their applications have begun to shift from military toward commercial. Digital communications through UWA channels differ substantially from those in other media, such as radio channels, due to severe signal degradations caused by multipath propagation and high temporal and spatial variability of the chan...
متن کامل