Patents by Inventor Rafael Arcangel Cepeda Lopez
Rafael Arcangel Cepeda Lopez has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
-
Patent number: 9077597Abstract: A data transmission apparatus and a method of modifying a symbol constellation for use in the data transmission apparatus, wherein a processor receives a starting symbol constellation suitable for use in a frequency domain parallel modulation system and defined in a complex space. The starting symbol constellation does not necessarily comprise a symbol at a zero point in the complex space. The processor is configured to locate or move one of the symbols of the starting symbol constellation at the zero point of the complex space. The newly created symbol constellation may be stored in a storage medium, such as volatile or non-volatile storage, or immediately used for data transmission by mapping bits of data to the symbol constellation and by transmitting the mapped data to a receiver of a frequency domain parallel modulation system.Type: GrantFiled: July 15, 2010Date of Patent: July 7, 2015Assignee: Kabushiki Kaisha ToshibaInventor: Rafael Arcangel Cepeda Lopez
-
Patent number: 9025618Abstract: According to one embodiment there is provided a wireless communication device comprising a plurality of antennas and operable to transmit data on a plurality of subcarriers from one or more of said plurality of antennas over a communication channel, the device comprising a receiver configured to receive signals via each of said plurality of antennas, a processor configured to determine the number of subcarriers that can be allocated to one or more of said plurality of antennas for data transmission on the basis of received signal metrics associated with said received signals, and an antenna selector configured to select one or more of said plurality of antennas for transmitting data on said plurality of subcarriers based on said determination.Type: GrantFiled: May 23, 2012Date of Patent: May 5, 2015Assignee: Kabushiki Kaisha ToshibaInventors: Rafael Arcangel Cepeda Lopez, Justin Coon
-
Publication number: 20120300717Abstract: According to one embodiment there is provided a wireless communication device comprising a plurality of antennas and operable to transmit data on a plurality of subcarriers from one or more of said plurality of antennas over a communication channel, the device comprising a receiver configured to receive signals via each of said plurality of antennas, a processor configured to determine the number of subcarriers that can be allocated to one or more of said plurality of antennas for data transmission on the basis of received signal metrics associated with said received signals, and an antenna selector configured to select one or more of said plurality of antennas for transmitting data on said plurality of subcarriers based on said determination.Type: ApplicationFiled: May 23, 2012Publication date: November 29, 2012Applicant: Kabushiki Kaisha ToshibaInventors: Rafael Arcangel CEPEDA LOPEZ, Justin Coon
-
Publication number: 20110013683Abstract: According to an embodiment there is provided a method of modifying a symbol constellation for use in a data transmission apparatus. The method comprises receiving at a processor a starting symbol constellation suitable for use in a frequency domain parallel modulation system and defined in a complex space. The starting symbol constellation does not necessarily comprise a symbol at a zero point in the complex space. The processor is used to locate or move one of the symbols of the starting symbol constellation at the zero point of the complex space. The newly created symbol constellation may be stored in a storage medium, such as volatile or non-volatile storage, or immediately used for data transmission by mapping bits of data to the symbol constellation and by transmitting the mapped data to a receiver of a frequency domain parallel modulation system.Type: ApplicationFiled: July 15, 2010Publication date: January 20, 2011Applicant: KABUSHIKI KAISHA TOSHIBAInventor: Rafael Arcangel CEPEDA LOPEZ
-
Patent number: 7342954Abstract: The invention relates to communication between terminals. Where communication is over an ideal channel then a high throughput modulation scheme can be used. Where the terminals suffer interference or noise, transmission can be modified to a more robust modulation scheme. The modulation scheme for a signal to be transmitted from the terminal is normally selected based up measurements made on a signal received by the terminal. However, the uplink and downlink between two terminals may not be experiencing the same interference and noise. For example, an interfering source may affect one terminal more than another. Under these circumstances, the terminal will not get a good picture of the status of the channel or link over which it is about to transmit. Therefore, the invention provides a system where quality information is passed from the terminal receiving a signal to the terminal which sent the signal to help to determine the most appropriate modulation scheme.Type: GrantFiled: February 25, 2003Date of Patent: March 11, 2008Assignee: Kabushiki Kaisha ToshibaInventors: Michael Philip Fitton, Rafael Arcangel Cepeda Lopez
-
Patent number: 7330505Abstract: An equalizer for a digital communications system includes a first buffer to store received data prior to equalisation; a second buffer to store error-checked received data; a channel estimator coupled to the first and second buffers to determine a channel estimate using the received data from the first buffer and the error-checked data from the second buffer; and a control unit coupled to the channel estimator to update a channel estimate for use by the equalizer in equalizing the received data. The control unit performs the updating conditional upon a difference between the channel estimate and a previous channel estimate used for equalizing the received data. A look-up table is coupled to the control unit and a calculating device is coupled to the look-up table to calculate and store, in the look-up table, data obtained by applying the channel estimate to a sequence of symbols.Type: GrantFiled: August 15, 2003Date of Patent: February 12, 2008Assignee: Kabushiki Kaisha ToshibaInventors: Michael Philip Fitton, Siew Chung Leong, Douglas John Gargin, Rafael Arcangel Cepeda Lopez
-
Publication number: 20040101072Abstract: This invention is generally concerned with equalisation in digital communications systems, and more particularly with improved methods and apparatus for MLSE (Maximum Likelihood Sequence Estimation) equalisation.Type: ApplicationFiled: August 15, 2003Publication date: May 27, 2004Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Michael Philip Fitton, Siew Chung Leong, Douglas John Gargin, Rafael Arcangel Cepeda Lopez
-
Publication number: 20040085917Abstract: This invention is generally concerned with the reception of high rate digital data, and more particularly with methods and apparatus for improved channel estimation in high rate digital data communications systems, particularly packet data communications systems.Type: ApplicationFiled: August 6, 2003Publication date: May 6, 2004Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Michael Philip Fitton, Siew Chung Leong, Douglas John Gargin, Rafael Arcangel Cepeda Lopez
-
Publication number: 20040004998Abstract: The invention relates to communication between terminals. Where communication is over an ideal channel then a high throughput modulation scheme can be used. Where the terminals suffer interference or noise, transmission can be modified to a more robust modulation scheme. The modulation scheme for a signal to be transmitted from the terminal is normally selected based up measurements made on a signal received by the terminal. However, the uplink and downlink between two terminals may not be experiencing the same interference and noise. For example, an interfering source may affect one terminal more than another. Under these circumstances, the terminal will not get a good picture of the status of the channel or link over which it is about to transmit. Therefore, the invention provides a system where quality information is passed from the terminal receiving a signal to the terminal which sent the signal to help to determine the most appropriate modulation scheme.Type: ApplicationFiled: February 25, 2003Publication date: January 8, 2004Applicant: Kabushiki Kaisha ToshibaInventors: Michael Philip Fitton, Rafael Arcangel Cepeda Lopez