A novel scheme of multicarrier modulation with the discrete cosine transform

In this work, we derive a novel multicarrier modulation based on the Type-I even discrete cosine transform (DCT1e), which includes new procedures to carry out both the channel estimation and the signal reconstruction. By using a small number of training symbols, we achieve an accurate estimation of the channel's impulse response (CIR) using a novel mirror, replicate and add (MIRA) procedure. The proposed scheme does not require knowing the length of the CIR and is valid even in the presence of spectral nones. We provide the theoretical results that guarantee the validity of the developed technique. After the estimation process, the transmitted symbols are also reconstructed by means of the DCT1e using the same novel MIRA scheme. The conditions that ensure a perfect reconstruction in the absence of noise are also provided in this case. Numerical simulations illustrate the excellent behaviour of the proposed approach, both in terms of channel estimation and recovery of the transmitted information.Ministerio de Economía y Competitivida

Cognitive Radio Systems

Cognitive radio is a hot research area for future wireless communications in the recent years. In order to increase the spectrum utilization, cognitive radio makes it possible for unlicensed users to access the spectrum unoccupied by licensed users. Cognitive radio let the equipments more intelligent to communicate with each other in a spectrum-aware manner and provide a new approach for the co-existence of multiple wireless systems. The goal of this book is to provide highlights of the current research topics in the field of cognitive radio systems. The book consists of 17 chapters, addressing various problems in cognitive radio systems

NASA Patent Abstracts bibliography: A continuing bibliography. Section 2: Indexes (supplement 20)

Entries for approximately 4000 citations for the period May 1969 through December 1981 are listed. Subject, invention, source, number, and accession number indexes are included