Pilot-aided ML schemes for joint beamforming and channel estimation in WCDMA systems

This paper proposes semi-blind channel estimation and interference cancellation schemes for the reception of pilot-aided signals in WCDMA systems. It is shown that the performance of classical training-based schemes is severely degraded due to the code-multiplexing (as opposed to time-multiplexing) of traffic and pilot signals. The time-dispersivity of the channel destroys the orthogonality between the traffic signal and the pilot, and consequently the traffic signal appears as a new interfering signal for the channel estimation/beamforming algorithm. In order to avoid this effect, we propose techniques that exploit both the presence of the training sequence and the structure of the traffic signal in a semi-blind fashion.Peer ReviewedPostprint (published version

Canonical Noether symmetries and commutativity properties for gauge systems

For a dynamical system defined by a singular Lagrangian, canonical Noether symmetries are characterized in terms of their commutation relations with the evolution operators of Lagrangian and Hamiltonian formalisms. Separate characterizations are given in phase space, in velocity space, and through an evolution operator that links both spaces.Comment: 22 pages; some references updated, an uncited reference deleted, minor style change

Mol·luscs epibionts de Charonia lampas (Linnaeus, 1758) (Mollusca, Gastropoda) de la badia de Palma

Abstract not availabl

In memoriam Josep Maria Palau i Camps (1914-1996)

Abstract not availabl

La fauna endèmica Iberobalear i la seva conservació

Ibero-balearic endemic fauna and its conservation. The Iberian peninsula and the Balearic Islands constitute two outstanding territories in terms of animal biodiversity and endemic species. The continental freshwater fish, the reptiles and amphibians, and to a lesser extent birds, make up the groups of most unique vertebrates and those most renowned as threatened species. The biodiversity of Iberian invertebrates seems very high, but huge research efforts and accurate studies are necessary before their diversity can be quantified

Joint beamforming and channel estimation for pilot-aided WCDMA systems

The problem of joint beamforming and channel estimation for multi-rate multi-code systems is addressed. Usual schemes perform this filtering/estimation operation making use of a training sequence time-multiplexed with the transmitted data. However if pilot and traffic signals are transmitted simultaneously using distinct code allocation-as it is the case in recent standards such as cdma2000 or WCDMA-these schemes tend to fail. This paper proposes semi-blind techniques to overcome the uplink auto-interfering effects of such systems. It is shown that the semi-blind approach yields substantially better performance results thanks to the implicit modeling of the unknown traffic data.Peer ReviewedPostprint (published version