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—Multi-packet reception (MPR) has recently received attention for use in military wireless ad hoc networks because of the potential to greatly improve spatial reuse. However, MPR typically requires complicated hardware that makes it prohibitive to implement in many current military platforms. An alternative, cross-layer approach is to use an overlapped(More)
The problem of secret sharing over the Gaussian wiretap channel is considered. A source and a destination intend to share secret information over a Gaussian channel in the presence of a wiretapper who observes the transmission through another Gaussian channel. Two constraints are imposed on the source-to-destination channel; namely, the source can transmit(More)
Secret sharing over the fast-fading MIMO wiretap channel is considered. A source and a destination try to share secret information over a fast-fading MIMO channel in the presence of a wiretapper who also makes channel observations that are different from but correlated to those made by the destination. An interactive authenticated unrestricted public(More)
— A coding scheme based on irregular low-density parity-check (LDPC) codes is proposed to send secret messages from a source over the Gaussian wiretap channel to a destination in the presence of a wiretapper, with the restriction that the source can send only binary phase-shift keyed (BPSK) symbols. The secrecy performance of the proposed coding scheme is(More)
Timely information about highway traffic conditions is very important for the Department of Transportation (DOT) and other relevant agencies. Such live information would be very important when traffic incidents or accidents occur. An aerial view is the best for traffic situations, particularly over highways. Unmanned aircraft equipped with video cameras(More)
One of the most promising approaches to improving communication efficiency in wireless communication systems is the use of multiuser diversity. Although it has been widely investigated and shown feasible and efficient in cellular networks, there is little work for the ad hoc networks, especially in real protocol and algorithm design. In this paper, we(More)
In wireless ad hoc networks (WANets), multihop routing may result in a radio knowing the content of transmissions of nearby radios. This knowledge can be used to improve spatial reuse in the network, thereby enhancing network throughput. Consider two radios, Alice and Bob, that are neighbors in a WANet not employing spread-spectrum multiple access. Suppose(More)
Superposition coding techniques can be used to improve communications efficiency in a variety of scenarios. These techniques are particularly appropriate for applications in which there are spatial or temporal disparities in received signal-to-noise ratios (SNRs). In this paper, we consider the application of superposition coding to improve the throughput(More)
— In this paper, we propose and evaluate the performance of a new adaptive HARQ technique that utilizes the correlation among bit errors at the output of a convolutional decoder. The proposed correlated bit-error hybrid ARQ (CB-HARQ) uses error events encountered in a soft-input soft-output (SISO) decoder to capture the correlation in bit errors.(More)