Technological areas of interest:

- Signal processing for fixed, mobile and/or celular broadband access (DSL, cable, Wifi, Wimax, extended GSM, B3G, LTE, etc).

- Broadband RF front-end transceiver design.

- Spectrum Sharing – Cognitive radios – software defined radio.

Objectives:

During last decade of the XX century, telecommunications services were protagonist of an enormous advance at the global level, making true the concept of “global economy” that we know today. World wide technological achievements were performed based on cooperative (or synergetic) efforts, among researchers, product developers and users.

Due to different reasons (social, economical and/or cultural) the same innovation process was not motivated in our country (we were treated mostly as consumers, not as producers, of technology). As a result, we have only incipient plans of support in the area (mostly from guvernamental agencies) without counterpart (paradoxically) from industry.

A brief list of (urgent?) objectives to fill in this gap in the mid-term is the following:

- Develop competent working people (based in engineering education and training).

- Dominate the innovation process (basic applied research by means of PhDs education) toward technologic cluster formation.

- Develop new products and/or services for the global market.

- Generate a critical mass of professional engineers able to boost the local telecommunication industry.

- Participate, in a wide and institutional form, in the standardization process of products and services.

- Stimulate, facilitate and obtain the support for the exchange of experiences with similar working groups (local and foreign countries).

Signal processing for the future communication systems

In the following we are going to discuss several aspects related to the enormous number of activities envisioned, mainly for the next decade, for broadband wireless communications as the main actor. These aspects take into account the broad application area where Signal Processing is a key tool. Following a brief motivation of the class and type of services and/or applications to be considered, a more general discussion of the advantages and benefits of the new technologies are introduced. One of the keys to produce these benefits will be an efficient integration of the available spectrum, the services and the standards. After that, a discussion of some basic requirements for the systems, to give an idea of the magnitude of the challenges to solve, is presented. Indeed, a specific analysis of the areas related to these challenges is other of the aspects discussed.

Motivation

Some examples that require signal processing for their realization are:

- Sensor networks for animal tracking (RFID), forestal production, plantations, etc.

- Mobile internet access for a whole student class simultaneously.

- Temperature measurement, lighting control and monitoring web cameras in individual rooms of a residence without requirement of any wired infrastructure.

- Cars forming a network, that also have a warning system for risk situations (accidents, fog, etc.) or orientation (dangegous crossing, speed limits, etc.)

- Localization of belongings, books, pets, etc., or helping system in a disaster place.

These are some of the promises of wireless networks and broadband technologies of next generation. In that context is evident not only the necessity of definition of new specifications of infrastructure and services but also the search for new algorithms and methodologies of signal processing. Some of the specific related problems that we want to abord are the following:

- “Cocktail party problem”: It is possible to have a big number of people communicating simultaneously in a wireless environment, all in the same frequency band? Taking into account the spectrum constraints, this has scientific and practical interest. How the individual users can be recovered, maintaining traffic, minimizing latency, and minimizing interuser interference, etc?

- Infraestructure: what kind of signal processing is required to obtain “mobile internet”, where PDAs (personal digital assistants) act as nodes of variable structure networks? Is important to take into account that users should begin a transmission in any moment and, as a consequence, different user packets could overlap. Despite that this can be defined as a communication protocol problem, only including signal processing elements (estimation, detection, and interference reduction) is how high transmission rates can be achieved.

- RF nonlinearities in transceivers: This problem (called “dirty RF in the specific literature) comes from the imperfections owned by analog front-end design (as a consequence also of more flexible and reconfigurable digital designs).

Benefits of mobile broadband communications

Last decade was witness of the development of two key industries that generate an enormous growing in developed economies: mobile communications and internet. These two industries brought significative benefits to users, industries and national economies. For example, net benefit due to mobile communications in Great Britain economy in 2007 was estimated in €500 per capita. In a similar vein, a 2007 report by Cisco estimated that considering only the adoption of internet based solutions in USA would result in an annual grow of 0.43 %. Moreover, a recent study of Deloitte - Touche consulting suggests that an increase of mobile communications in 10 % would result in a consequent increase of 1.2 % in GDP. Read more...

General requirements of the new systems

Several are the factors contributed to the success of mobile telephony in general and GSM in particular. However, one that can not be disregarded is the existence of compatible standards and an objective spectrum definition. In particular, the availability of a spectrum organized for GSM allowed to the user to do and receive calls and / or messages, independent of the country place. That was a key ingredient for the success. Other technologies that also used compatible standards and similar sprectrum also had similar dividends.

Today, mobile communications industry is in a similar crossroad, and is the possibility of make a true mobile internet the problem that must be solved. Towards that objective plain collaboration is required, in addition to the use of the planification and experiences of industry and administrations at a global scale. Read more...

Signal processing in mobile communications toward 2020

Signal processing for mobile communications had a major impact as an essential tool of economic grow in the last decade. This can be concluded by the features obtained in cellular networks (GSM, UMTS, LET, etc.) and more recently by the performance of wireless computer networks (Wifi, Wimax). Next decade will bring dramatic developments in the area by different reasons, among them

- Increasing demand of broadband services like HDTV and data file acces of increasing size.

- Increasing rates available in fixed networks (DSL, 1000-base-T, FTTH and FTTB), whose users will expect to access in a wireless context.

- Gain in efficiency available through coordinated networks of devices and autonomous sensors, with application to security and vigilance.

Some conclusions

Even when the social and economic perspectives associated to signal processing in future mobile communications are highly promissory, its implementation and consolidation will require a high degree of integration, collaboration and/or participation not only of the guvernamental agencies but also from industry.

From guvernamental agencies point of view, human resources education in addition to the actualization of laboratories and, more important, the opening in the regulatory design process (standard adoption, regulatory aspects, etc.) are some of the aspects that will lead to a sustainable development.

From the human resources education point of view, if we want to collaborate seriously with industry, we must work to include academic and research centers in the process of development – regulation – utilization of communication systems. To that purpose institutional effort and commitment will be required to incentivate local initiatives and to facilitate the cooperation with industry that absorb young engineers.

From the industry point of view, the initiatives related to this thematic area, signal processing for communications, will favour clairly new inititatives to allow efficient solutions at the regional market level (since one of the objectives is to maintain the scale economy aspects of the applications).

Finally, form the general technical perspective, the reconfigurability and flexibility that will characterize devices and services of future mobile communication systems will demand considerable inventiveness and ingenuousness to solve the efficiency challenges required. A common tool to solve many of these challenges is the statistical signal processing.