摘要:
A system capable of operation with dynamic sockets includes a plurality of communications devices. Each of the plurality of communications devices includes high band channel radio resources capable of communications at 900-2800 MHz and socket radio resources capable of communications at 30-1000 MHz. The high band channel radio resources and the socket radio resources are significantly separated in frequency so that the high band channel radio resources and the socket radio resources are suitable for concurrent operation with no interference and minimal isolation, co-site problems to solve in each of the plurality of communications devices. The plurality of communications devices are connected to a unifying mesh network by the high band channel radio resources. The unifying mesh network is suitable for allowing the plurality of communications devices to communicate with one another. When data needs to be transferred among a group of communications devices, a dynamic socket connection is negotiated on the unifying mesh network and is then formed with the socket radio resources. The dynamic socket formation is suitable for allowing the unifying mesh network to offload continuous receiver-directed or multicast traffic from the unifying mesh network channel and to free up public ad hoc communications bandwidth of the unifying mesh network.
摘要:
A receiver for computationally efficient signal acquisition of spread-spectrum chips affected by Doppler shift in an advanced tactical data link. Received signals with a very low signal-to-noise ratio are parsed in a multi-stage signal acquisition circuit architecture, and compared to a known sequence to determine correlation over a subset of the known sequence. Chip-rate-coherent correlation is performed over an interval of time for which the effect of Doppler shift on the chip rate are negligible. A non-coherent block then integrates intermediate metrics to obtain final metrics for the entire known sequence. The parsing of the correlation into subsets and stages allows for a more computationally efficient solution to the Doppler shift chip rate error problem by reducing the number of intermediate metrics that must be computed at high speed.
摘要:
An architecture for a spread-spectrum transmitter-receiver system in an advanced tactical data link that allows the receiver to readily acquire and synchronize to a desired LPD signal. Signal acquisition is performed with a cyclic range search that uses multiple redundant known sequences mapped to a known message sequence in a highly repeated manner. By employing the invariance of the speed of light, and synchronicity between transmitter and receiver, the architecture can significantly reduce the computational complexity of the receiver. Additionally, the architecture enables ad hoc channel access, controlled latency, distance estimation, and distance-directed transmissions.
摘要:
An apparatus and method for signal separation and SINR improvement is disclosed. In particular, disclosed is an iterative technique whereby a noisy signal, that may include signals from one or more distinct emitters, is first improved through an SINR improvement technique. Next, one signal from the noisy signal is identified and a reference signal substantially free of noise and interference is generated for this signal, and then this reference signal is subtracted from the noisy signal. This process is repeated until no other signals may be identified. In this way, the signal with the highest SINR may be identified first and then removed from the original signal. As such, the identified signal is no longer present as interference for the remaining signals, thus improving each of the remaining signals' respective SINRs.
摘要:
The present invention is a method and system for estimating interference. Packet characteristics of relevant packets within the channel at a given point in time may be processed. For example, a power level, occupied frequency and corresponding time references may be accumulated and stored for each relevant packet within the channel at a given point in time. As each packet is processed for demodulation, the channel samples, at which interference occurred, may be appropriately weighted based on the packet characteristics. Advantageously, the nature of the interfering channel traffic may be measured to properly de-weight the interference in a computationally efficient manner.
摘要:
An apparatus for identifying a specific emitter in the presence of noise and/or interference is disclosed. The apparatus includes a sensor configured to sense radio frequency signal data, the signal data containing noise and signal from at least one emitter, a reference estimation unit configured to estimate a reference signal relating to the signal transmitted by one emitter, a feature estimation unit configured to generate one or more estimates of one or more feature from the reference signal and the signal transmitted by that particular emitter, and an emitter identifier configured to identify the signal transmitted by that particular emitter as belonging to a specific device using one or more feature estimates. The emitter identifier identifies the signal transmitted by that particular emitter as belonging to a specific device using Gaussian Mixture Models and the Bayesian decision engine.
摘要:
An apparatus for sensing and classifying radio communications is provided. The apparatus includes one or more sensor units configured to detect radio frequency signals, a signal classifier configured to classify the detected radio frequency signals into a classification, the classification including at least one known signal type and an unknown signal type, a clustering learning algorithm capable of finding clusters of common signals among the previously seen unknown signals. The system is then further configured to use these clusters to retrain the signal classifier to recognize these signals as a new signal type.
摘要:
The present invention is directed to a small size and light weight small form factor user system suitable for having TTNT connectivity which consumes minimum power to operate. The small form factor user system having TTNT connectivity may be capable of interacting in a low latency real time manner with airborne networks. The small form factor user system having TTNT connectivity may have significantly reduced radio power consumption and form factor size through maintaining core capabilities of the full size TTNT terminal while relaxing other capabilities. An encapsulated message structure may be utilized to simplify communication between the TTNT small form factor user system and the full size TTNT nodes.
摘要:
Disclosed is an apparatus for estimating the features of a radio frequency signal including a reference signal generator configured for generating a reference signal from a complex signal and one or more feature estimation units configured to generate one or more feature estimates from the reference signal and the complex signal. Techniques for creating reference signals from both signals spread by a scrambling code and FM signals are discussed.
摘要:
Spectral environment estimation systems and methods are provided for use with frequency hopped communications systems. A spectral sensor is configured to receive input signals from a signal aperture and to perform spectral estimations on the input signals to generate a frequency domain spectral estimate. Ordinary spectral characterization circuitry is configured to receive the frequency domain spectral estimate as an input and to produce an ordinary frequency domain spectral environment estimate based on the spectral estimate. Frequency hopping translation circuitry is configured to receive the frequency domain spectral estimate from the spectral sensor as an input and to produce a de-hopped channel domain spectral estimate based on the frequency domain spectral estimate. De-hopped spectral characterization circuitry is configured to receive the de-hopped channel domain spectral estimate as an input and to produce a de-hopped channel domain spectral environment estimate based on the de-hopped spectral estimate. Spectral environment integration circuitry is configured to generate an integrated spectral environment estimate, based on the ordinary frequency domain spectral environment estimate and the de-hopped channel domain spectral environment estimate, for use by networked communications systems or devices in controlling frequency hopped communications.