Abstract: A communication system receives a jammed signal including a sequence of complex numbers encoding one or combination of symbols transmitted by multiple transmitters. The system transforms the sequence of complex numbers into an image of real numbers having at least two columns and multiple rows, with real values of real and imaginary parts of each complex number forming different columns but the same row of the first image, processes the image with a neural network trained to suppress the wideband signal in the received signal, and detects the symbols transmitted by the transmitters from the de-jammed signal.

Abstract: A communication system receives a jammed signal including a sequence of complex numbers encoding one or combination of symbols transmitted by multiple transmitters. The system transforms the sequence of complex numbers into an image of real numbers having at least two columns and multiple rows, with real values of real and imaginary parts of each complex number forming different columns but the same row of the first image, processes the image with a neural network trained to suppress the wideband signal in the received signal, and detects the symbols transmitted by the transmitters from the de jammed signal.

Abstract: Nodes in an ad hoc mobile network are monitored to provide secure routing of packets. Malicious or selfish behaviors by nodes are used to maintain and distribute node reputations. Based on the reputation, the most secure route, which can have multiple paths, is selected for packet communications. In conjunction with secure routing, a forward error correction code is adaptively optimized according to the reputation through every adjacent nodes along the route to avoid eavesdropping and falsification by malicious nodes.

Abstract: Nodes in an ad hoc mobile network are monitored to provide secure routing of packets. Malicious or selfish behaviors by nodes are used to maintain and distribute node reputations. Based on the reputation, the most secure route, which can have multiple paths, is selected for packet communications. In conjunction with secure routing, a forward error correction code is adaptively optimized according to the reputation through every adjacent nodes along the route to avoid eavesdropping and falsification by malicious nodes.

Abstract: Codewords encoded using non-coherent codes and received at a receiver via non-coherent channels in a multi-input, multiple output (MIMO) network using orthogonal frequency demultiplexing (OFDM) are decode by concatenating multiple adjacent codewords of a received signal into a superblock at the receiver. A projector matrix based on a codebook is predetermining. Each codeword in the superblock is projected onto an orthogonal complement of a correspond transmitted codeword using the projector matrix to obtain a corresponding distance metric of a generalized likelihood ratio test (GLRT) codeword. A minimal distance metric is selected to obtain an estimate of the transmitted codeword corresponding to a transmitted signal.