Multichannel receivers from ofdm and tdma in mobile communications

This paper addresses the use of multichannel receivers for blind equalization in TDMA under frequency selective channels and OFDM systems in frequency flat fading channels. A new criteria is proposed for blind equalization of finite length mobile channels.Peer ReviewedPostprint (published version

Transform modulations for mobile communications

A new modulation scheme called transform modulations is proposed which improves the system performance in frequency-flat fading mobile channels. They ameliorate the effect of the fadings over the transmitted signal by spreading the information in time, using a linear transform operator. The design of this scheme is discussed and its advantages are shown by means of simulations. The relationship of this scheme with OFDM modulation is also analyzed.Peer ReviewedPostprint (published version

Diversity techniques for blind channel equalization in mobile communications

A blind algorithm for channel distortion compensation is presented which can be employed in spatial or temporal diversity receivers. The proposed technique can be used in frequency selective and frequency flat fading mobile channels, using burst transmission schemes in the first case and OFDM modulation in the second one. The algorithm is base on a deterministic criteria and is suited for estimation when short sets of data are available.Peer ReviewedPostprint (published version

Blind equalization based on spatial and temporal diversity in block coded modulations

Linear block codes can be applied in spatial and/or temporal diversity receivers in order to develop high performance schemes for blind equalization in mobile communications. The proposed technique uses the structure of the encoded transmitted information (with redundancy) to achieve equalization schemes based on a deterministic criterion. Simulations show that the proposed technique is more efficient than other schemes that follow similar equalizer structures. The result is an algorithm that provides the design of blind channel equalizers in low EbNo scenarios.Peer ReviewedPostprint (published version

Redundancy in block coded modulations for channel equalization based on spatial and temporal diversity

Linear block codes in the complex field can be applied in spatial and/or temporal diversity receivers in order to develop high performance schemes for (almost-) blind equalization in mobile communications. The proposed technique uses the structure of the encoded transmitted information (with redundancy) to achieve equalization schemes based on a deterministic criterion. Simulations show that the proposed technique is more efficient than other schemes that follow similar equalizer structures. The result is an algorithm that provides the design of channel equalizers in low EbNo scenarios.Peer ReviewedPostprint (published version

The literal sense and the spiritual understanding of Scripture according to St. Thomas Aquinas

In contemporary Biblical hermeneutics, there is a confusion about what the literal and spiritual senses are. From this confusión, it follows that the interpreter does not know the sense to be reached and that there is a considerable distance between what the Bible meant when it was written and what it now means in the Church. St. Thomas has a clear doctrine about what is the literal sense and what the spiritual sense, which can clarify this confusion and avoid the negative consequences it has for exegesis. From this doctrine, there are two essential contributions that can serve this purpose: the literal sense is mainly the sense intended by the divine author, and the spiritual understanding is what allows the interpreter to reach the literal sense of the New Testament, the key that opens up the meaning of revelation and of Scripture.Sens dosłowny i sens duchowy rozumienia Pisma Świętego według św. Tomasza z AkwinuWe współczesnej hermeneutyce biblijnej istnieje zamieszanie dotyczące tego, czym jest dosłowny i duchowy sens. Z tego zamieszania wynika to, że interpretatorzy nie wiedzą, jaki jest sens, który mają osiągnąć i jaki jest dystans między tym, co Biblia znaczyła, kiedy była napisana i co teraz znaczy w Kościele. Św. Tomasz podaje jasną doktrynę o tym, czym jest sens dosłowny i duchowy, która może wyjaśnić to zamieszanie i uniknąć jego negatywnych skutków dla egzegezy. Z tej doktryny wynika, że sens dosłowny jest tym, który zamierzał sam autor, duchowy zaś jest tym, co uznaje interpretator, aby ubogacić dosłowny sens Nowego Testamentu. Jest to klucz, który poszerza znaczenie objawienia i Pisma Świętego

Linear precoding for mutual information maximization in MIMO systems

We study the design of linear precoders for maximization of the mutual information in MIMO systems with arbitrary constellations and with perfect channel state information at the transmitter. We derive the structure of the optimum precoder and we show that the mutual information is concave in a quadratic function of the precoder coefficients. An iterative algorithm is also proposed to find this optimum value.Postprint (published version

Diversity in mobile communications for blind detection of block-coded modulations

Spatial, temporal, and frequency diversity structures are analyzed to address the blind equalization problem in the presence of time-variant frequency selective channels. The aim of the paper is to present equalization schemes useful in front of fast changing channel responses. The best solution is a deterministic blind criterion that allows direct channel equalization and symbol detection. The main contribution of this paper is to present deterministic blind equalization schemes in CDMA systems (frequency diversity) to reduce the impact of the time-variant frequency selective channel.Peer ReviewedPostprint (published version

Estimacio de frequencia en comunicacions via satel.lit amb dfd's adaptatius

Senyal i comunicacions digitals per satèl·lit. Mètodes de descomposició en valors singulars, per estimació conjunta de freqüència i sincronisme de bit SENYAL I COMUNICACIONS DIGIPeer ReviewedPostprint (published version