This paper designs an underwater acoustic communication system based on tamed spread spectrum and Frequency Hopping Multiple Access (FHMA) for multiple underwater vehicles. In this system, multiple underwater vehicles...This paper designs an underwater acoustic communication system based on tamed spread spectrum and Frequency Hopping Multiple Access (FHMA) for multiple underwater vehicles. In this system, multiple underwater vehicles can communicate with the console on the water surface simultaneously successfully. The communication system is com-posed of tamed spread spectrum modulation and demodulation, frequency hopping modulation and demodulation with synchronization function, 4FSK modulation and demodulation and Rake Receiver. In order to make the system more feasible, underwater channel and the effect of user number on Bit Error Ratio (BER) are also taken into account. The simulation results indicate that it is feasible to use this system to accomplish underwater communication reliably for multiple users due to the low BER.展开更多
A novel family of frequency-hopping(FH)se-quences based on iterated block cipher is proposed for frequencyhopping multiple-access(FHMA)communica-tions.The design offers a class of nonlinear FH codes with high security...A novel family of frequency-hopping(FH)se-quences based on iterated block cipher is proposed for frequencyhopping multiple-access(FHMA)communica-tions.The design offers a class of nonlinear FH codes with high security,large linear span and a uniform spread over the entire frequency bandwidth.Moreover,FH sequences among the family are independent from each other and they perform as well as random patterns in terms of multi-ple access interference in anti-jamming applications.With the performance of packet error and throughput for FHMA network being derived in theory,many numerical results of the 3DES sequences are presented,comparing with those of shift register sequences and chaotic FH sequences.Effi-ciently implemented in field programmable gate arrays(FPGA),the generator prototype of the proposed sequence has been realized and incorporated into fast FH radio.展开更多
文摘This paper designs an underwater acoustic communication system based on tamed spread spectrum and Frequency Hopping Multiple Access (FHMA) for multiple underwater vehicles. In this system, multiple underwater vehicles can communicate with the console on the water surface simultaneously successfully. The communication system is com-posed of tamed spread spectrum modulation and demodulation, frequency hopping modulation and demodulation with synchronization function, 4FSK modulation and demodulation and Rake Receiver. In order to make the system more feasible, underwater channel and the effect of user number on Bit Error Ratio (BER) are also taken into account. The simulation results indicate that it is feasible to use this system to accomplish underwater communication reliably for multiple users due to the low BER.
基金supported by the National Natural Science Foundation of China(No.60402040)Natural Sci-ence Foundation of Shaanxi Province(No.2005F29)the 10th Fok Ying Tong Education Foundation for Young Teacher(No.101065),China.
文摘A novel family of frequency-hopping(FH)se-quences based on iterated block cipher is proposed for frequencyhopping multiple-access(FHMA)communica-tions.The design offers a class of nonlinear FH codes with high security,large linear span and a uniform spread over the entire frequency bandwidth.Moreover,FH sequences among the family are independent from each other and they perform as well as random patterns in terms of multi-ple access interference in anti-jamming applications.With the performance of packet error and throughput for FHMA network being derived in theory,many numerical results of the 3DES sequences are presented,comparing with those of shift register sequences and chaotic FH sequences.Effi-ciently implemented in field programmable gate arrays(FPGA),the generator prototype of the proposed sequence has been realized and incorporated into fast FH radio.
