Multi agent radio frequency propagation simulator

#The present invention relates to a multi agent radio frequency propagation simulator (MARPS), specifically used to determine performance of a radio frequency (RF) communications system prior to open air range (OAR) testing. A desirable interface between multi-agents is through ‘over the air’ RF connections which include not only the intended direct RF communications paths but also highly variable multi-ray propagation, range attenuation, external RF influences and near earth influence. These influences are all difficult to predict, control, and repeat in an outdoor environment. This outdoor testing, as has traditionally been done, is extremely expensive while simultaneously providing less data points than more controlled events, and the testing events are generally not repeatable. A need exists for an ability to interconnect multiple devices for laboratory simulation of this outdoor environment.

#Currently in certain types of antenna design fields the correlation between model and simulations (M&S), hardware-in-the-loop (HITL) testing, and open air range testing has been minimal. The complexity of open air test ranges cannot be fully captured in modeling and simulation or in hardware-in-the-loop testing. Open air test ranges introduce many uncontrolled variables that not only affect the performance of an RF communications system but also impact the quality of the test data. An open air test is heavily influenced by a number of factors that other testing methods cannot completely account for, including: the ambient electromagnetic environment (EME) an RF system is operating in; the antenna placement, including the antenna's placement as compared to other antennas; the soil properties of the location being tested in; the physical terrain; the placement of the RF system within that terrain; multi-ray reflection signals; desirable signals; undesirable signals propagating in the area; hostile signals that might be trying to disrupts the RF systems functionality; general system variability; and other factors.

#In open air test ranges the multiplicity of the before mentioned variables impact the quality of the data gathered from an open air test. Thus, it is difficult to determine cause and effect from open air testing because of the many variables introduced by the environment that cannot be completely accounted for with other testing methods. Furthermore, the results of the open air test are not repeatable, and the phenomenology is not clear.

#The detailed description of the drawings particularly refers to the accompanying figures in which:

#FIG. 1 is a block diagram of a RF propagation path simulator according to an illustrative embodiment of the disclosure;

#FIG. 2 is a diagram of propagation paths of a RF propagation path simulator according to an illustrative embodiment of the disclosure;

#The embodiments of the invention described herein are not intended to be exhaustive or to limit the invention to precise forms disclosed. Rather, the embodiments selected for description have been chosen to enable one skilled in the art to practice the invention.

#FIG. 1 shows a high-level block diagram of a path simulator 10 in accordance with one embodiment of the invention. Path simulator 10 can be a scalable port system that simulates RF paths that exist in a real-world environment. Exemplary path simulator 10 comprises a system controller 12, a data sequencer 14, a plurality of RF path control modules 16, a spectrum analyzer 18, one or more SOIs 20, an EME generator 22, and one or more device pairs 24. A SOI in this embodiment can be a source of interference (SUT) or focus which generates interference between a receiver and transmitter or other elements in the EME.

#Both exemplary device pairs 24 and SOIs 20 are meant to send and receive RF signals. An example device pair 24 is made up of a device pair transmitter 25 (Tx) and a device pair receiver 26 (Rx). SOIs 20 send and receive RF signals from all other RF devices connected to path simulator 10 but device pairs 24 only send and receive signals to and from SOIs 20 and not from other RF systems connected to path simulator 10. In this case, signals of exemplary device pairs 24 do not interact with other signals from other device pairs 24 because of the complexity of path simulator 10 increases exponentially with each added device pair 24 or SOI 20 and RF signals from a device pair 24 have little or no effect on any other device pair 24 connected to path simulator 10. The number of paths to be simulated by path simulator 10 can be reduced by orders of magnitude by not allowing RF signals from device pairs 24 to interact with other device pairs 24. A SOI 20 receives signals from all other SOIs 20, from all device pairs 24, and from EME generator 22 because SOIs 20 can be devices that path simulator 10 is exhaustively testing.