Integration and Utilization of GPS Location Capabilities in An Advanced Spread Spectrum Multi-Nest, Multi-Hop, Peer-to-Peer, CDMA Wireless Communications Network

摘要

An advanced RF Wireless communications technology (termed Stealthware) has been developed and demonstrated and is being patented and implemented in self-contained, battery powered, mobile transceivers. These transceivers are able to enter, edit, format, compress, store, transmit, receive, process, display and output digitized voice, digital data and digitized image/video messages. This technology, based on direct sequence spread spectrum (DSSS) theory, is unique because the transmitted waveforms contain no modulation characteristics or artifacts (features) and are manifest as Gaussian noise in the ambient electromagnetic (EM) spectrum. Due to its Gaussian noise-like nature, the propagated waveform is not detectable by unintended receivers, is not affected by any noise in the ambient EM spectrum, does not interfere with any other signals present in the EM Spectrum and is not interfered by an other signals present in the EM spectrum. A fully functional, highly mobile unit, the Stealthware. Transceiver includes Doppler compensation, multipath distortion mitigation, optimized digitized voice, data and image/video compression, message error detection and correction (EDAC) and adaptive power control (APC) capabilities. For maximum effectiveness, the APC function has to know the line-of-sight (LOS) range from the transmitting transceiver to the intended receiver. The Stealthware transceivers are designed to be communications nodes in a proprietary peer-to-peer, multi-hopping, multi-nesting, code division multiple access (CDMA), DSSS wireless voice, data and image communications network. This network has unique attributes due to the nature of the previously described Stealthware waveform. With the peer-to-peer network topology, every transceiver has equal status and is able to communicate with every other transceiver in its network and other independent, coexisting, colocated networks (multi-nesting). If a receiving node in a network is beyond the LOS range of a sending node, then a transmitted message is received by one or more intermediate nodes in the network and retransmitted (multi-hopped) to the intended node. The APC and multi-hopping functions in each transceiver depend on knowing the LOS distance between itself and all other transceivers in its own and intercommunicating, nested networks. Although there are RF ranging techniques applicable to this situation, the most accurate and effective method for transceiver location is for it to have an internal GPS signal receiver and processor. Upon external interrogation and/or periodically, each transceiver transmits its GPS location coordinates in a broadcast message to all other intended transceivers in LOS distance. Using the received location coordinates messages from the other transceivers, each transceiver calculates other transceivers absolute position and range between transceivers, stores these data internally and generates a transceiver location map for display. The stored transceivers range data is used by a message transmitter to set the optimum APC output RF power level for the receiver and determined the best multi-hopping path for forwarding a received message to the intended receiver in a bent pipe transmission situation.