Centre Tecnològic de Telecomunicacions de Catalunya

ANNUAL REPORT 2013

Internationally published Patents

CTTC patents submissions have reached the deadline to be internationally published in 15 cases out of 16.

METHOD AND SYSTEM FOR ESTIMATING DIRECTIONS-OF ARRIVAL IN LOW POWER OR LOW SAMPLE SIZE SCENARIOS
International Application number: PCT/EP2006/002167
Publication number: WO 2007/101451 A1
This invention presents a system and a methodology for estimating the directions of arrival of one or several radio signals. The typical mechanisms used in this kind of detection need a minimum power level. The proposed solution, permits to considerably decrease the value of this threshold, that is, it allows the correct estimation of the directions of arrival of the signals with lower power. Besides, the invented method is especially useful in situations in which the number of available observations is small. To sum up, the patented system allows to improve the reception of signals when conditions are deficient. The author of this patent is Dr. X. Mestre.

RESIDUAL CARRIER FREQUENCY OFFSET ESTIMATION AND CORRECTION IN OFDM MULTIANTENNA SYSTEMS
International Application number:
PCT/EP2006/010419
Publication number: WO 2008/052573 A1
This invention focuses on the frequency offset estimation and correction in multicarrier systems, particularly, in Orthogonal Frequency Division Multiplexing (OFDM) systems with multiple antennas at both the transmitter and the receiver. The proposed method exploits the whole capabilities of the information contained in the OFDM frame, and not only the preamble of the data frame. The authors of this invention are Dr. Antonio Pascual, L. Ventura and X. Nieto

METHOD FOR LOGICAL DEPLOYMENT, UNDEPLOYMENT AND MONITORING OF A TARGET IP NETWORK.
International Application number:
PCT/EP2006/009960
Publication number: WO 2008/046429 A1
This patent discloses a method for simplifying the task of logical deployment to configure a target IP network topology, which is to be physically deployed on a background IP network. Furthermore, this method allows real time monitoring on the network elements previously deployed in the target IP network, being able to alert the administrator when any element involved in the IP network (a node, process in a node, or an interface between nodes) fails or goes wrong. Moreover, the invention provides an intuitive and user-friendly mechanism for automatically configuring and reconfiguring multiple IP network topologies, involving configuration issues such as number of nodes and link connectivity, as well as remotely configuring the execution of processes at each node (i.e. routing or signalling processes). The authors of this invention are F. Galán and Dr. R. Muñoz.

METHOD AND SYSTEM FOR ROBUSTLY TRANSMITTING THE MINIMUM POWER IN MULTI-USER AND MULTI-ANTENNA COMMUNICATIONS SYSTEMS WITH IMPERFECT CHANNEL KNOWLEDGE.
International Application number:
PCT/EP2006/006244
Publication number: WO 2008/000284 A1
The patent presents a method and system for robustly transmitting the minimum power from a transmitter of a base station to the mobile users attached to the base station, while guaranteeing a certain quality of service per user. Minimizing the total transmitted power has multiple advantages. Apart from the fact of lowering the energetic resource consumption, there is less electromagnetic radiation in the environment and the total system interference level is minimized.  Previous designs of minimum power linear transmission architectures assume that both the transmitter (at the base station) and the user receivers (mobile terminals) have perfect knowledge of the channel state information. However, in a practical scenario, this assumption is not realistic, mainly for wireless systems where the fluctuations of the channel can be fast. The presented design is robust to the uncertainty in the channel estimate. The authors of this invention are Dr. M. Payaró, Dr. A. Pascual and Prof.  M. A. Lagunas.

METHOD FOR ESTIMATING THE TIME OF ARRIVAL IN ULTRA WIDEBAND SYSTEMS.
International Application number:
PCT/2006/066529
Publication number: WO 2008/034466 A1
This patent relates to the estimation of the time-of-arrival (ToA) of signals transmitted through a wireless medium, which is based on a frequency domain approach. More precisely, the present invention relates to the estimation of the ToA of signals in ultra wideband (UWB) systems. Previous solutions are based on time domain approaches and rely on measurements of the propagation time undertaken by the signal when travelling between a target  node and a reference node. However, this approach suffers from (a) practical limitations of maximum likelihood solution due to the requirement of very high sampling rates and (b) large estimation time of correlation-based approaches due to the required search over a large number of bins. The presented patent solves both problems. The authors of this invention are Dr. M. Nájar, Dr. M. Navarro, and Dr. C. Ibars.

METHOD AND SYSTEM FOR MEASURING QUALITY OF NETWORKING NODES.
International Application number:
PCT/EP2007/053660
Publication number: WO 2008/125146 A1
This patent presents a method that allows obtaining a characterization of the quality of a certain node and an assessment of its suitability to a planned deployment, prior to the use of said node in a real network scenario, based on carrier sense measurements. Thus, the present invention is useful to aid configuration and calibration processes for network deployment. Moreover it defines and accurately determines the values of two quality metrics to characterize respectively the accuracy of a node in carrier sensing and the ability of said node to cope with a given workload of concurrent incoming and outgoing communication traffic. A testing controlled scenario is provided for allowing the knowledge of these two quality metrics separately, detecting the presence of the maximum value measured for concurrent workload of the node under test in the measurement of the accuracy of said node in carrier sensing. The authors of this invention are M. Portolés, Dr. A. Krendzel, and Dr. J. Mangues.

POWER ALLOCATION METHOD IN MULTIANTENNA SYSTEMS UNDER PARTIAL CHANNEL KNOWLEDGE.
International Application number:
PCT/EP2007/056491
Publication number: WO 2009/000329 A1
This patent proposes a method for allocating a minimum downlink power from a transmitter of a cellular multi-user multi-antenna communications system. That minimum amount of power is dependent on a predetermined quality of service requirement per user and on the power of the interfering signals. The system requires a partial knowledge of the channel, although it is robust to said assumed uncertainty in said partial channel state information. The authors of the patent are Prof. A. I. Pérez-Neira and Dr. N.  Zorba.

BEAMFORMING TECHNIQUE FOR BROADBAND SATELLITE COMMUNICATIONS
International Application number:
PCT/EP2007/060971
Publication number: WO 2009/036814 A1
In the last years, investment in satellite communications has focused on spreading the satellite signal to vast terrestrial areas, on reducing the price of satellite and receivers and on reducing interference. Typical satellite services do not suffer from substantial limitation of bitrate. However, nowadays there is a need of using advanced digital applications via satellite, which implies the need of increasing the bitrate capacity of the satellite channel. The present invention aims to solve the above-mentioned problems by means of a method of assigning precoding gain, which optimizes the satellite scenario characteristics and multiuser diversity, providing a high system performance, while requiring a low complexity design,  in a satellite system under the control of a single terrestrial gateway. A scheduler in the gateway runs a multibeam opportunistic beamforming (MOB) technique, wherein the satellite antennas radiation pattern, the channel Line of Sight (LOS) information and the multiuser diversity are incorporated in the design process of the precoder. The invention presented in this patent aims to achieve an improvement in the rate of transmission without increasing its complexity. The current method applies MIMO techniques (use of multiple antennas in both transmission and reception, Multiple-Input / Multiple-Output) for the the user segment of the forward link (FL) and precoding of the radiation beam in the transmitter depending on the radiation pattern of the satellite antennas and on the line of sight channel characteristics. The authors of this patent are Dr. N.  Zorba, Dr. M.  Realp, and Prof. A. I. Pérez-Neira.

METHOD AND DIGITAL COMMUNICATION DEVICE FOR RECEIVING DATA USING QAM SYMBOLS
International Application number:
PCT/EP2008054541
Publication number: WO 2009/127243 A1
The presented invention relates to a digital communication system which applies channel coding and QAM modulation. In QAM, at the transmitter, a number Q of bits is mapped to one QAM symbol, which is transmitted over the channel. At the receiver side, for each QAM symbol, a de-mapping is performed in order to obtain an L-value for each bit which corresponds to the QAM symbol. These L-values provide not only an estimation of the transmitted bits but also give information about their reliability. The presented invention describes a method and a device for computing these L-values in a very efficient manner, making use of a distance calculation which does not require the determination of the closest constellation point. The author of this invention is Dr. S. Pfletschinger.

METHOD OF EFFICIENT CHANNEL ALLOCATION IN WIRELESS SYSTEMS
International Application number:
PCT/EP2008/056760
Publication number:  WO 2009/135534 A1
This invention presents a method for efficiently allocating a downlink channel from a transmitter to a user selected from a plurality of users in a wireless network providing different service applications. The authors of this invention are Dr. N. Zorba, Dr. C. Verikoukis and Prof. A. I. Pérez-Neira.

SIGNAL PROCESSING DEVICE AND METHOD FORDETECTING AND LOCATING SPECTRAL SHAPES
International Application number:
PCT/2008/058098
Publication number: WO 2009/143902 A1
This invention presents a method and device for detecting a target spectrum and its frequency location in a scenario affected by strong jammers or other interferers.

The detection is based on the geodesic distance between the correlation matrix (RD) of the received signal and the correlation matrix (RT) of the target spectrum (TS), which is assumed to be known in shape and bandwidth. The detection happens when the threshold is overcome. The frequency location is based on the minimization of the mean square error between RD and RT. The authors of this invention are Prof. M. Á. Lagunas, Prof. A. I. Pérez-Neira, Dr. X. Mestre and M. Á. Rojas.

JOINT DEMODULATION AND SYNCHRONIZATION IN ULTRAWIDEBAND SYSTEMS
International Application number:
PCT/EP/2008/062920
Publication number: WO 2010/025780 A1
This invention presents a method for demodulating at a receiver a plurality of symbols contained in a e.g. UWB received signal. The receiver is supposed to have knowledge of a time hopping sequence vector c of the transmitted signal. The method consists of the following steps: It first generates a plurality of frequency-domain samples from the received signal.

From said plurality of frequency-domain samples and said time hopping sequence vector c, it applies a coarse estimation for identifying the beginning of a first complete symbol in an acquisition interval. It applies a stage for fine estimation of the time delay of each by searching a relative maximum at which a signal energy distribution exceeds a certain threshold Pth; from said fine estimation of the time delay of each symbol, the symbols are demodulated. The authors of this invention are Dr. M. Najar and Dr. M. Navarro.

METHOD AND APPARATUS FOR MEDIUM ACCESS CONTROL IN A WIRELESS BROADBAND SYSTEM WITH MIMO OR MISO TECHNOLOGY WITH MULTIUSER CAPABILITIES
International Application number:
PCT/EP/2009/057276
Publication number: WO 2010/142343 A1)
This invention presents a method and apparatus for medium access control in a wireless broadband system with multiuser MIMO/MISO technology comprising the steps of a transmitter broadcasting a polling message to all the users associated to said transmitter (Tx). The users answer with reply messages during a time slot. The transmitter performs the scheduling, the transmission of data and scheduled users send the corresponding acknowledgment messages. Preferably, only users which measure a Signal to Noise plus Interference Ratio over a pre-defined threshold for a transmission beam send reply messages. The authors of this invention are Dr. C. Verikoukis, E. Kartsakli, Dr. N. Zorba and Dr. L. Alonso.

REFLECTARRAY ANTENNA SYSTEM
International Application number:
PCT/EP2009/061316
Publication number: WO 2011/026513 A1
The reflectarray comprises a plurality of cells integrated in a Printed Circuit Board (PCB) and externally illuminated by an input signal from a feeding source at a given frequency, so that an output signal is reflected. Each cell of the reflectarray is an Active Integrated Antenna (AIA) formed by a passive radiating element connected to an active circuit, which can be either an oscillator, or a push-push oscillator or a Self. Oscillating Mixer (SOM). The passive radiating circuit is placed on a reflective surface forming a side of the reflectarray and the active circuit is placed on the reverse side. The active circuit produces an output signal with a frequency related to the input frequency and the oscillation frequency of said active circuit. This phase relationship is determined by an output phase variation, which is controlled by electronic means integrated in the reflectarray system, which allows an output phase variation interval even higher than 180°. The authors of this invention are Dr. A. Georgiadis and Dr. A. Collado.

FEMTO-TOLL. A FEMTOCELL-BASED TOLL COLLECTION SYSTEM
International Application number:
PCT/EP2011/063595
Publication number: WO 2013/020580 A1
This invention enables the payment of highway, bridge or tunnel fees by means of mobile phones. The presence of femtocells in the toll station is necessary to allow the communication between the mobile terminals and the payment system. When the vehicle traverses the toll station, the system identifies the subscriber, checks whether he is a registered user and, if so, it triggers the payment of the corresponding fee and notifies the user. The authors of this invention are J. Nin, Dr. P. Dini, Dr. C. Antón-Haro, Dr. J. Mangues.