Marvell Hispania, S.l.u.

Diseño De Sistemasen Silicio, S.a.

Marvell Hispania, S.l.

Juan Carlos Riveiro Insúa

Jorge Vicente Blasco Claret

Salvador Iranzo Molinero

José Abad Molina

Luis Manuel Torres Cantón

Agustín Badenes Corella

David Ruiz López

Judit Carreras Areny

Aitor Garcia San Jose

Agustin B Denes Corella

A system for determining a frequency error of an orthogonal frequency division multiplexing (OFDM) signal having a first frequency. The system includes a plurality of filters configured to output a plurality of second signals, each of the plurality of second signals corresponding to a respective one of a plurality of different frequency bands of the OFDM signal. Each of the plurality of second signals includes a corresponding synchronization symbol associated with the OFDM signal. A Fourier transform circuit is configured to receive the plurality of second signals from each of the plurality of filters and output the plurality of second signals. The system is configured to determine the frequency error of the OFDM signal based on the synchronization symbols of the plurality of second signals.

Process of synchronization in the time and frequency domain of multiple equipments in a transmission system with OFDM modulation

A system for synchronization of an orthogonal frequency division multiplexing signal having a first frequency. The system includes filters configured to receive the OFDM signal, and output second signals corresponding to different frequency bands of the OFDM signal. Each of the second signals includes a corresponding synchronization symbol associated with the OFDM signal, and the synchronization symbols of each of the second signals are the same. The system further includes a Fourier transform circuit configured to receive the second signals from the filters, and output the second signals. Each of the second signals has a second frequency. The system is configured to detect the synchronization symbols in the second signals, and detect a start of OFDM symbols in the OFDM signal based on the detected synchronization symbols. The start of the OFDM symbols corresponds to an average of a plurality of estimations of the start of the OFDM symbols.

It is characterized in that, maintaining the sampling frequency of the digital-analog converter of the transmitter and the analog-digital converter of the receiver, the bandwidth, the spectral position of the OFDM signal, the shape of the spectrum of the OFDM signal that is transmitted, the level of the spectrum of the OFDM signal that is transmitted, or any combination of the above, are selectively and independently varied for the transmission path and for the reception path, in order to permit the configuration of the spectrum of the OFDM signal in terms of bandwidth, position in frequency and power transmitted for being adapted to the regulations of different countries and to the channels found in the different sections of the electrical network. All these changes are carried out without affecting the analog components of the system, in other words, with the same physical implementation.

Method for the spectral configuration of signals modulated by means of orthogonal frequency division multiplexing (OFDM) for an electrical network

This permits the transmission of signals over the electricity network in such a way that the spectral density of power is adjusted to the regulations in the current rules by means of the possibility of introducing notches in transmission in an efficient manner. It is characterised by the adjustment of the power in one or more carriers of an OFDM signal for generating these notches, through the use of IDFTs of at least 1024 points (if the IDFT is complex) or at least 2048 points (if the IDFT is real) and through the use of a window to multiply the symbols to be transmitted in time.

Process for obtaining notches in the transmission of signals over the electricity network

The invention describes a data transmission method for a multi-user. multipoint-to-multipoint digital data transmission system involving a plurality of users equipment () which are bidirectionally connected via physical medium (). The method is intended to communicate one (-) users equipment at different speeds, sending multiple frames, maintaining the bandwidth and maximum latency values required by each destination user (-). Further, this method consists in using the percentage reserve of the frame, providing a quality of service based on that required by the user equipment and supplying a criterion for dynamically assigning the packets sent to each user equipment in the frame, grouping or dividing them.

Process for the transmission of data by a multi-user, point to multi-point digital data transmission system

This method reduces the variance of the estimation of the signal-to-noise rate in a multiuser digital communications system. These communications require a sending of a phase reference symbol prior to sending a information, where the estimation is made of the signal-to-noise rate in order to use a modulation with a maximum number of bits per symbol, maintaining a bit error probability in reception within certain given margins. The method minimizes and equalizes the variance of the samples obtained for the different values, even and odd of bits per carrier, which the system uses. The estimation is necessary for selecting the number of bits per carrier in order to be adapted to the channel and as back-up information in the event of using a receiver with diversity.

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Valencia, Spain

Juan Carlos Riveiro Insúa