| Underwater acoustic sensor networks(UWASN)have been an important tool in implementing underwater applications like ocean marine data acquisition,disaster warning and so on.However,underwater transmission link is faced with poor reliability and long propagation delay,presenting a great challenge in achieving reliable communication.Digital fountain codes(DFC)and network coding(NC)are all efficient coding techniques in UWASN.They both show good adaptability to the UWASN.Based on the project funded by the National Natural Science Foundation,the combination algorithms of DFC and NC and relative routing protocols in the UWASN are deeply investigated in this paper,including1)Based on the study of the basic theory of DFC and NC,the existing combination strategies are further studied.Then the research analyzes the main factors that may influence the performance based on the combination methods and the problems in applying the existing strategies to UWASN.2)Optimized combination coding algorithm between LT code and network coding based on the protection of high degree packets for UWASN is put forward and the performance of LTNC-HP are tested in the terms of the normalized energy consumption,successful delivery ratio and so on.And the results show that the advanced algorithm performs better in term of transmission reliability and end-to-end delay.3)The transmission mechanism based on routing protocol and coding are studied,particularly,the disadvantages of the normalized energy consumption and long delay of which is discussed.The paper proposes a combination coding method based on advanced vector-based forwarding protocol to promote the protocol transmission efficiency effectively.4)An UWASN model is established based on OPNET modeler.Performance indicators like network throughput and the normalized energy consumption are tested to analysis the influence of network structures on the proposed combination coding scheme.Then the better adaptability to the UWASN of VBFA-LTNC are verified. |
PDF Full Text Request