2019_programme: SPREAD SPECTRUM MULTI-CARRIER COMMUNICATION IN INTERFERENCE-LIMITED ACOUSTIC REGIMES

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  • Session: 05. Underwater Communications and Networking
    Organiser(s): Tsimenidis Charalampos, Mitchell Paul, Pelekanakis konstantinos
  • Lecture: SPREAD SPECTRUM MULTI-CARRIER COMMUNICATION IN INTERFERENCE-LIMITED ACOUSTIC REGIMES [invited]
    Paper ID: 862
    Author(s): Li Zhengnan, Stojanovic Milica
    Presenter: Stojanovic Milica
    Presentation type: oral
    Abstract: Interference-limited regimes occur in underwater acoustic communication scenarios for a variety of reasons: (i) ambient noise levels can be elevated in certain environments, (ii) intentional interference can be present in adversarial situations, (iii) the signal level can be reduced deliberately so as to achieve security, and (iv) multi-user interference can be present in networked systems. We focus here on signal detection in low SNR regimes using multi-carrier modulation in the form of orthogonal frequency division multiplexing (OFDM). We propose a transmission / detection method that integrates OFDM with direct-sequence spectrum spreading. Specifically, we capitalize on coupling the channel estimation / signal detection with structured coding to obtain an efficient receiver design. We consider both coherent and differentially coherent detectionand extend the detection principles to multi-channel receiver configurations. In addition, spread-spectrum OFDM detection is coupled with a custom-designed frequency synchronization techniques to counteract the motion-induced Doppler frequency shifting. Using experimental recordings from the Mobile Acoustic Communication Experiment (MACE'10), where signals were transmitted over a 3 km -- 7 km shallow-water channel in the 10.5 kHz -- 15.5 kHz band, with relative transmitter / receiver motion of up to 1.5 m/s, we study the system performance in terms of the mean squared error and symbol error rate in data detection. Varying the level of externally added noise, we show that the proposed methods provide excellent performance while maintaining simplicity needed for a practical implementation.
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  • Corresponding author: Mr Li Zhengnan
    Affiliation: Northeastern University
    Country: United States
    e-mail:

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