摘要:
A system for wireless asset tracking is disclosed. The system includes a plurality of mobile devices. Each mobile device performs two spreading operations with two distinct PN codes, a first PN code and a second PN code. Data is transmitted by each mobile device using a burst direct sequence spread spectrum radio signal. The system also includes at least three base stations. Each base station is configured to receive the burst direct sequence spread spectrum radio signals from the mobile devices which includes decoding the signals by first de-spreading with the second PN code and second de-spreading with the first PN code. Each base station is further configured to add a timestamp to each data packet received. A system for calculating the location of the mobile devices creates location information for each mobile device by calculating the time difference of arrival of received bursts for each base station.
摘要:
A spread spectrum communications system using long, scalable PN sequences to achieve variable communication rates using a low-complexity and scalable matched filter architecture to provide a large processing gain, robust recovery of multiple devices in long reach, high ambient-noise environments.
摘要:
A spread spectrum communications system using long, scalable PN sequences to achieve variable communication rates using a low-complexity and scalable matched filter architecture to provide a large processing gain, robust recovery of multiple devices in long reach, high ambient-noise environments.
摘要:
A spread spectrum communications system adapted to receive simultaneous signals from multiple transmitters, separates frequency error and equalizes and decodes continuous streams of data sets from a plurality of matched filters with frequency correction and which sorts through data and successfully decodes data bits. The spread spectrum communications system includes a transmitter and a receiver. The receiver includes an RF receiver. At least one PNB matched filter receives signals from the RF receiver. A plurality of frequency shifters receives a signal from the at least one PNB matched filter. A plurality of PNA matched filters receives data from the at least one PNB matched filter and the plurality of frequency shifters. An equalizer/decoder receives signals from the plurality of PNA matched filters.
摘要:
A spread spectrum communications system adapted to receive simultaneous signals from multiple transmitters, separates frequency error and equalizes and decodes continuous streams of data sets from a plurality of matched filters with frequency correction and which sorts through data and successfully decodes data bits.
摘要:
A system for wireless asset tracking is disclosed. The system includes a plurality of mobile devices. Each mobile device performs two spreading operations with two distinct PN codes, a first PN code and a second PN code. Data is transmitted by each mobile device using a burst direct sequence spread spectrum radio signal. The system also includes at least three base stations. Each base station is configured to receive the burst direct sequence spread spectrum radio signals from the mobile devices which includes decoding the signals by first de-spreading with the second PN code and second de-spreading with the first PN code. Each base station is further configured to add a timestamp to each data packet received. A system for calculating the location of the mobile devices creates location information for each mobile device by calculating the time difference of arrival of received bursts for each base station.
摘要:
A spread spectrum communications system uses long, scalable PN sequences to achieve variable communication rates. A low-complexity and scalable matched filter architecture is used to provide a large processing gain and robust recovery of multiple devices in long reach, high ambient-noise environments. The spread spectrum communications system includes a transmitter and a receiver. The receiver includes an RF receiver and a first matched filter receiving data from the RF receiver. A plurality of phase/frequency shifters receives a signal from the first matched filter. A plurality of second matched filters receive data from the plurality of phase/frequency shifters. An equalizer/decoder receives signals from the plurality of phase/frequency shifters.
摘要:
A spread spectrum communications system using long, scalable PN sequences to achieve variable communication rates using a low-complexity and scalable matched filter architecture to provide a large processing gain, robust recovery of multiple devices in long reach, high ambient-noise environments.
摘要:
A transmitter for a spread spectrum communications system may include a data source, a first multiplier/mixer spreading data from said data source with a first pseudo noise source, a second multiplier/mixer spreading data from said first mixer with a second pseudo noise source, and an RF transmitter. A receiver for a spread spectrum communications system may include an RF receiver, a first matched filter receiving data from said RF receiver, a plurality of phase/frequency shifters receiving a signal from said first matched filter, a plurality of second matched filters receiving data from said plurality of phase/frequency shifters, and an equalizer/decoder receiving signals from said plurality of second matched filters.
摘要:
A spread spectrum communications system using long, scalable PN sequences to achieve variable communication rates using a low-complexity and scalable matched filter architecture to provide a large processing gain, robust recovery of multiple devices in long reach, high ambient-noise environments.