The direct sequence ultra-wideband （DS-UWB） is a promising technology for short-range wireless communications. The UWB signal is a stream of very low power density and ultra-short pulses, and the great potential of ...The direct sequence ultra-wideband （DS-UWB） is a promising technology for short-range wireless communications. The UWB signal is a stream of very low power density and ultra-short pulses, and the great potential of DS-UWB depends critically on the success of timing acquisition. A rapid acquisition algorithm for reducing the acquisition time of the coarse pseudo-noise （PN） sequences is proposed. The algorithm utilizes the auxiliary sequence and bisearch strategy based on the threshold comparison criterion. Both theoretical analysis and simulation tests show that with the proposed search strategy and simple operations over the symbol duration at the receiver, the proposed algorithm can considerably reduce the acquisition time even as it maintains the PN sequence acquisition probability in the DS-UWB system over the dense multipath environment.展开更多
The area navigation system,discussed in this paper,is composed of ground responders and a navigation terminal and can position a high-velocity aircraft and measure its velocity.This navigation system is silent at ordi...The area navigation system,discussed in this paper,is composed of ground responders and a navigation terminal and can position a high-velocity aircraft and measure its velocity.This navigation system is silent at ordinary times.It sends out a request signal when positioning is required for an aircraft,and then the ground responders send a signal for resolving the aircraft.Combining the direct sequence spread spectrum and frequency hopping,the concealed communication mode is used in the whole communication process,with short communication pulses as much as possible,so the system has strong concealment and anti-interference characteristics.As the transmission delay is apparent in the response communication mode,there is a big error where the common navigation algorithm is used for the positioning and velocity measurement of a high-velocity aircraft.In this paper,a new algorithm is proposed,which can eliminate the influence of response communication delay on the positioning of a high-velocity moving target to realize the precise positioning and velocity measurement of a high-velocity aircraft.展开更多
基金supported by the National Natural Science Foundation of China (60572024)the Doctoral Fund of the Ministry of Education of China (20050293003)the National Basic Research Program (2007CB310607)
文摘The direct sequence ultra-wideband （DS-UWB） is a promising technology for short-range wireless communications. The UWB signal is a stream of very low power density and ultra-short pulses, and the great potential of DS-UWB depends critically on the success of timing acquisition. A rapid acquisition algorithm for reducing the acquisition time of the coarse pseudo-noise （PN） sequences is proposed. The algorithm utilizes the auxiliary sequence and bisearch strategy based on the threshold comparison criterion. Both theoretical analysis and simulation tests show that with the proposed search strategy and simple operations over the symbol duration at the receiver, the proposed algorithm can considerably reduce the acquisition time even as it maintains the PN sequence acquisition probability in the DS-UWB system over the dense multipath environment.
文摘The area navigation system,discussed in this paper,is composed of ground responders and a navigation terminal and can position a high-velocity aircraft and measure its velocity.This navigation system is silent at ordinary times.It sends out a request signal when positioning is required for an aircraft,and then the ground responders send a signal for resolving the aircraft.Combining the direct sequence spread spectrum and frequency hopping,the concealed communication mode is used in the whole communication process,with short communication pulses as much as possible,so the system has strong concealment and anti-interference characteristics.As the transmission delay is apparent in the response communication mode,there is a big error where the common navigation algorithm is used for the positioning and velocity measurement of a high-velocity aircraft.In this paper,a new algorithm is proposed,which can eliminate the influence of response communication delay on the positioning of a high-velocity moving target to realize the precise positioning and velocity measurement of a high-velocity aircraft.
