Sea Technology: Multi-Carrier Wideband Acoustic Communications
نویسنده
چکیده
An alternative method for communicating over frequency-selective channels is multi-carrier modulation. In a multi-carrier system, the available bandwidth is divided into many narrow subbands, such that the channel distortion appears as flat (frequency-nonselective) within each subband. Thus, no equalization is needed per subband. Instead, modulation and demodulation have to be performed over multiple carriers.
منابع مشابه
Principles and Limitations of Ultra-Wideband FM Communications Systems
This paper presents a novel UWB communications system using double FM: a low-modulation index digital FSK followed by a high-modulation index analog FM to create a constant-envelope UWB signal. FDMA techniques at the subcarrier level are exploited to accommodate multiple users. The system is intended for low (1–10 kbps) and medium (100–1000 kbps) bit rate, and short-range WPAN systems. A wideba...
متن کاملPulsed ALOHA - a Form of Multiaccess UWB Communications
Pulsed ALOHA is a form of impulse Ultra-Wideband communication where a bit is carried with each pulse, rather than using a time spreading code. Pulsed ALOHA and Wideband ALOHA are perfect fits to low energy wide-bandwidth communication. They permit energy-efficient higher data rates. Pulsed ALOHA has some unique advantages in collision avoidance and collision tolerance over Wideband ALOHA, when...
متن کاملMulticarrier Underwater Acoustic Communications over Fast-Varying Channels
Multicarrier modulation in the form of orthogonal frequency division multiplexing (OFDM) has prevailed in recent broadband wireless radio applications due to the low complexity of receivers required to deal with highly dispersive channels. This fact motivates the use of OFDM in underwater environments. However, underwater acoustic (UWA) channels are far more challenging than their radio counter...
متن کاملAn Ad-hoc Communication Environment for Multi- Carrier Marine Data Networks
Data communications at sea nowadays depend on mainly satellite and radio media which are, however, not adequate to exchange massive information due to its own high cost and low bandwidth. Ships at sea in the near future would need broad and stable maritime data communication systems like on land. In this paper, we propose multi-carrier-based ad hoc network model and multi-carrier-based ad hoc r...
متن کاملResearch on Mine Roadway Communication System Based on Multicarrier Spread Spectrum Technology
The coal information system based on the electric power line was put forward after analyzing briefly the structure of mine distribution power network in roadway underground, connected with communication and monitoring networks existed already. The system uses a multi-level distributed bus network structure, roadway where harsh conditions, using a combination of multi-carrier and spread spectrum...
متن کامل