This paper proposes a study of quality of service (QoS) in cognitive radio networks. This study is based on a stochastic optimization method called shuffled frog leaping algorithm (SFLA). The interest of the SFLA algorithm is to guarantee a better solution in a multi-carrier context in order to satisfy the requirements of the secondary user (SU).

A multi-pattern encoding and decoding scheme is presented that extends the family of spectral associative memories (SAMs) to include gray-level, or analog patterns. SAMs are frequency-domain formulations of associative memory that combine the extrinsic redundancy of neural networks with the in-phase, quadrature, and complex modulation schemes of communications. Considerable coding gain occurs a...

Clustering in wireless sensor networks (WSNs) is an important technique to prolong lifetime of a WSN. This paper proposes energy efficient multi-level clustering scheme called Power Aware Multi-level Clustering (PAMC) for homogeneous wireless sensor networks. Further, we also apply the proposed multi-level clustering scheme for heterogeneous wireless sensor networks. Due to large area of deploy...