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This paper presents an efficient IrisCode classifier, built from phase features which uses AdaBoost for the selection of Gabor wavelets bandwidths. The final iris classifier consists of a weighted contribution of weak classifiers. As weak classifiers we use three-split decision trees that identify a candidate based on the Levenshtein distance between phase vectors of the respective iris images. Our experiments show that the Levenshtein distance has better discrimination in comparing IrisCodes than the Hamming distance. Our process also differs from existing methods because the wavelengths of the Gabor filters used, and their final weights in the decision function, are chosen from the robust final classifier, instead of being fixed and/or limited by the programmer, thus yielding higher iris recognition rates. A pyramidal strategy for cascading filters with increasing complexity makes the system suitable for real-time operation. We have designed a processor array to accelerate the computation of the Levenshtein distance. The processing elements are simple basic cells, interconnected by relatively short paths, which makes it suitable for a VLSI implementation.

In this paper we present PbP-EDCA, a Full Duplex (FD) MAC protocol that operates according to the high-priority access rules of the standard IEEE 802.11 EDCA. With PbP-EDCA, nodes that win a contention perform a sequence of narrow-band orthogonal transmissions rather than one single wide-band. PbP-EDCA employs the Carrier Sense Multiple Access/Collision Avoidance (CSMA/CA) to avoid sequences starting at the same time and takes advantage of self-interference free radios to enable multiple simultaneous orthogonal transmissions to/from a single-radio access point. By exploiting FD and the EDCA contention values standardized for high-priority traffic classes, we show that PbP-EDCA can scale the gains claimed by single-link FD proposals in a network-wide domain. Our results indicate one scenario in which PbP-EDCA can achieve about 3× the capacity of the IEEE 802.11 half duplex MAC.

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