Patent application number | Description | Published |
20090041141 | PILOT PATTERN DESIGN FOR AN OFDM SYSTEM - The present invention relates to a transmitting device and a receiving device in a wireless orthogonal frequency division multiplex (OFDM) communication system with space time transmit diversity (STTD). Further, the present invention relates to a channel estimation method for performing a channel estimation in such a wireless communication system, in which the transmitting device comprises a first and a second antenna for transmitting signals with space time transmit diversity. The first and the second antenna means are arranged spaced apart from each other in a space diversity arrangement, whereby first and second pilot symbols are transmitted via said first and said second antenna means, respectively. Some of the second pilot symbols are orthogonal to corresponding ones of the first pilot symbols, so that a channel estimation to separately determine the transmission quality of signals transmitted from the first and the second antenna means, respectively, can be performed in a receiving device which receives the signals with only one single antenna. | 02-12-2009 |
20090041142 | PILOT PATTERN DESIGN FOR AN OFDM SYSTEM - A transmitting device for transmitting data symbols and pilot symbols in an OFDM transmission system; the device comprising symbol generating means for generating said data symbols and said pilot symbols, means for transmitting said data symbols and pilot symbols respectively by using a plurality of subcarriers of said OFDM transmission system, wherein said symbol generating means is designed to selectively generate a first type pilot symbol and a second type pilot symbol being orthogonal to said first type pilot symbol so that a pilot symbol pattern in the frequency dimension comprises at least said first type pilot symbol to be transmitted by using a predefined subcarrier and second type pilot symbol to be transmitted by using other predefined subcarrier, and wherein said pilot symbol pattern has a different pattern from a succeeding pilot symbol pattern in time dimension. | 02-12-2009 |
20090080561 | PILOT PATTERN DESIGN FOR A STTD SCHEME IN AN OFDM SYSTEM - A transmitting device for transmitting data and pilot symbols in an OFDM transmission system having transmission antennas. The device includes symbol generating means for generating data and pilot symbols, means for transmitting the data and pilot symbols using subcarriers of the OFDM system. The symbol generating means generates a first and second type pilot symbol, the second having an inverted value of the first so that a first pilot symbol pattern to be transmitted by using one of said plurality of transmission antennas has a different pattern in the frequency and time dimension from a second pilot symbol pattern to be transmitted by using another transmission antenna. First and second pilot symbols are comprised in respective first and second pilot symbol patterns, where at least some of the first and second pilot symbols have the same time allocation and being alternately identical and inverted to each other. | 03-26-2009 |
20090196382 | EQUALIZING STRUCTURE AND EQUALIZING METHOD - An equalizing structure and method for a wireless communication system receiving device, in which two or more transmit signals transmitted in parallel from one or more transmitters are received in received signal vectors representing two or more received data streams, the signals including information modulated onto carrier signals according to a modulation scheme, all possible transmit signals being represented by candidate constellation values in the signal constellation of the modulation scheme. A metric value calculator calculates metric values based on the received signal vectors and the product of channel estimation values with candidate signal vectors, each candidate signal vector including a candidate constellation value for each of the two or more transmit signals. A maximum likelihood detector detects one of the candidate signal vectors having a minimum Euclidean distance to a respective receive signal vector as a most likely transmit signal vector based on the metric values. A soft decision value calculator calculates a soft decision value for the most likely candidate signal vectors based on the candidate signal vectors of at least some of the metric values. | 08-06-2009 |
20090219981 | MINIMUM MEAN SQUARE ERROR EQUALISER WITH REDUCED COMPLEXITY - The present invention relates to the field of communication devices, e.g. wireless communication devices. More particularly, the present invention relates to the field of signal equalisation, especially minimum mean square error equalisation. The present invention especially relates to an equaliser for a communication device, a method of equalising one or more received signals and a software program product for carrying out the method. The present invention reduces the size of a look-up table needed for a division operation and, generally, provides for a reduced complexity of the equaliser and receiver. The equaliser for a communication device comprises a filter calculator for determining a channel power value based on one or more channel response values and selecting one of two or more equaliser structures based on said channel power value and based on at least one threshold value for separating the channel power values into at least two ranges; and a filter for equalising one or more received signals according to the selected equaliser structure. Advantageously, at least one of said equaliser structures corresponds to an, at least approximated, minimum mean square error equaliser structure or to an, at least approximated, suboptimal minimum mean square error equaliser structure. | 09-03-2009 |
20090257487 | VIDEO ROBUSTNESS USING SPATIAL AND TEMPORAL DIVERSITY - The present invention relates to the fields of wireless communication, video transmission, unequal error protection, time diversity, space diversity. The present invention especially relates to a transmitter, a receiver, a method of transmitting video data and a method for receiving video data. The transmitter for transmitting video data comprises: A transmission section, said transmission section comprising a parser for dividing said video data into at least two classes and dividing each class into one or more blocks. Hereby, with each class there is associated a different number. Said transmission section is adapted to transmit at least one block of each class once on each communication channel of a set communication channels, the number of communication channels comprised in the respective set being given by the number associated with the respective class. Further, different communication channels correspond to different transmission times and/or different transmit paths. The receiver for receiving video data comprises: A receiving section for receiving said video data on a plurality of communication channels and generating a plurality of partial signals, each partial signal corresponding to a different communication channel. Different communication channels correspond to different transmission times and/or different receive paths. A decoding and validating section comprising a decoder for decoding a first block of said video data based on a partial signal of a first number of at least two partial signals and an error detector for determining if said decoded first block of video data is corrupted. In case said decoded first block of video data is determined to be corrupted, said decoder is configured to decode said first block of video data based on an other signal of said first number of partial signals. | 10-15-2009 |
20090310719 | EQUALIZING STRUCTURE AND EQUALIZING METHOD - An equalizing structure and method for a wireless communication system receiving device, in which two or more transmit signals transmitted in parallel from one or more transmitters are received in received signal vectors representing two or more received data streams, the signals including information modulated onto carrier signals according to a modulation scheme, all possible transmit signals being represented by candidate constellation values in the signal constellation of the modulation scheme. A metric value calculator calculates metric values based on the received signal vectors and the product of channel estimation values with candidate signal vectors using absolute value calculations, each candidate signal vector including a candidate constellation value for each of the two or more transmit signals. A maximum likelihood detector detects one of the candidate signal vectors having a minimum Euclidean distance to a respective receive signal vector as a most likely transmit signal vector based on metric values. | 12-17-2009 |
20090310720 | EQUALIZING STRUCTURE AND EQUALIZING METHOD - An equalizing structure and method for a wireless communication system receiving device. Two or more transmit signals transmitted in parallel from one or more transmitters are received in received signal vectors representing two or more received data streams, the signals including information modulated onto carrier signals according to a modulation scheme, all possible transmit signals being represented by candidate constellation values in the signal constellation of the modulation scheme. A processor calculates an estimate for a constellation value of a received signal and determines a number of candidate constellation values in the vicinity of the estimated constellation value in the signal constellation. A metric value calculator calculates metric values based on the received signal vectors and the product of channel estimation values with candidate signal vectors. A maximum likelihood detector detects one of the candidate signal vectors having a minimum Euclidean distance to a respective received signal vector as a most likely transmit signal vector based on the metric values. | 12-17-2009 |
20100190450 | ITERATIVE BEAM SELECTION METHOD WITH RECEIVER AND TRANSMITTER DIVERSITY - The present invention relates to a method for determining the best transmitter and receiver beams with a reduced number of calculations for the best antenna beam arrangement between a transmitter and a receiver. The iterative routine within this method comprises a transmitter beam determination sequence, a feedback sequence and a receiver beam determination sequence. While calculating the best possible antenna beam arrangement, the antenna beam width does not require to be reduced. | 07-29-2010 |
20100195710 | RECEIVING APPARATUS WITH FREQUENCY DOMAIN EQUALIZER - The present invention relates to a receiving apparatus ( | 08-05-2010 |
20100210219 | BEAM SELECTION METHOD - The present invention relates to a method which analysis the characteristics of the received signal and selects the best beam arrangement for a transmitter/receiver pair for a given situation in a communication system. In particular, the channel delay profile provides characteristics which help to determine and evaluate the quality of a signal link. The result of this evaluation is used for selecting the best beam arrangement. | 08-19-2010 |
20100226453 | PILOT PATTERN DESIGN FOR A STTD SCHEME IN AN OFDM SYSTEM - A transmitting device for transmitting data symbols and pilot symbols in an OFDM transmission system; the device comprising symbol generating means for generating said data symbols and said pilot symbols, means for transmitting said data symbols and pilot symbols respectively by using a plurality of subcarriers of said OFDM transmission system, wherein said symbol generating means is designed to selectively generate a first type pilot symbol and a second type pilot symbol being orthogonal to said first type pilot symbol so that a pilot symbol pattern in the frequency dimension comprises at least said first type pilot symbol to be transmitted by using a predefined subcarrier and second type pilot symbol to be transmitted by using other predefined subcarrier, and wherein said pilot symbol pattern has a different pattern from a succeeding pilot symbol pattern in time dimension. | 09-09-2010 |
20100226462 | RECEIVING APPARATUS AND METHOD WITH NO OVERSAMPLING ANALOG TO DIGITAL CONVERSION - The present invention relates to a receiving apparatus for receiving signals in a wireless communication system, in which the signals comprise a dedicated channel estimation sequence, comprising an analog to digital converter adapted to convert received signals into digital samples with a sampling rate identical to a symbol rate of the received signals, a channel estimation means adapted to perform a channel estimation on the basis of the dedicated channel estimation sequence comprised in a digital samples of the received signals, an evaluation means adapted to evaluate the channel estimation result from the channel estimation means, and a control means adapted to control a phase of the sampling rate of the analog to digital converter on the basis of an evaluation of the channel estimation result. | 09-09-2010 |
20100266082 | RECEIVING APPARATUS AND METHOD WITH CLOCK DRIFT ESTIMATION AND COMPENSATION - The present invention relates to a receiving apparatus | 10-21-2010 |
20110182378 | PILOT PATTERN DESIGN FOR A STTD SCHEME IN AN OFDM SYSTEM - A transmitting device for transmitting data and pilot symbols in an OFDM transmission system having transmission antennas. The device includes symbol generating means for generating data and pilot symbols, means for transmitting the data and pilot symbols using subcarriers of the OFDM system. The symbol generating means generates a first and second type pilot symbol, the second having an inverted value of the first so that a first pilot symbol pattern to be transmitted by using one of said plurality of transmission antennas has a different pattern in the frequency and time dimension from a second pilot symbol pattern to be transmitted by using another transmission antenna. First and second pilot symbols are comprised in respective first and second pilot symbol patterns, where at least some of the first and second pilot symbols have the same time allocation and being alternately identical and inverted to each other. | 07-28-2011 |
20110188602 | PILOT PATTERN DESIGN FOR A STTD SCHEME IN AN OFDM SYSTEM - A transmitting device for transmitting data and pilot symbols in an OFDM transmission system having transmission antennas. The device includes symbol generating means for generating data said pilot symbols, means for transmitting the data and pilot symbols using subcarriers of the OFDM system. The symbol generating means generates a first and second type pilot symbol, the second having an inverted value of the first so that a first pilot symbol pattern to be transmitted by using one of said plurality of transmission antennas has a different pattern in the frequency and time dimension from a second pilot symbol pattern to be transmitted by using another transmission antenna. First and second pilot symbols are comprised in respective first and second pilot symbol patterns, where at least some of the first and second pilot symbols have the same time allocation and being alternately identical and inverted to each other. | 08-04-2011 |
20110273585 | ACTIVE IMAGING DEVICE AND METHOD FOR SPECKLE NOISE REDUCTION - The present invention relates to an active imaging device for imaging a scene, comprising a scene illuminator that illuminates said scene with radiation at multiple illumination frequencies or an illumination frequency range covering multiple illumination frequencies, a radiation detector that detects radiation received from said scene in response to said illumination and that generates detection data from said detected radiation, a feature identifier that analyses said detection data and identifies different features in said scene, a frequency selector that separately selects for the identified features one or more selected illumination frequencies resulting in the minimum speckle noise in an image of the respective feature constructed from the detection data, which have been generated from radiation received in response to the illumination of the scene with radiation at said one or more selected illumination frequencies, and an image constructor that constructs a final image from the detection data, wherein the image portions of the identified features are constructed from the detection data, which have been generated from radiation received in response to the illumination of the scene with radiation at said one or more selected illumination frequencies, and wherein said image portions are combined into the final image. | 11-10-2011 |
20120019690 | ACTIVE IMAGING DEVICE AND METHOD FOR SPECKLE NOISE REDUCTION - The present invention relates to an active imaging device and a corresponding device for imaging a scene, in particular for effectively reducing speckle noise. The proposed device comprises an illuminator that illuminates said scene with radiation, a radiation detector that detects radiation received from said scene in response to said illumination and that generates detection data from said detected radiation, an image constructor that constructs an image of said scene or one or more parts of said scene from the detection data, a noise reduction unit that processes said image by applying a one- or multi-dimensional transform to the complete image, to one or more parts of the image or to selected features in said image, and a transform selector that selects for the complete image, for one or more parts of the image or for selected features in said image a selected transform for application by said noise reduction unit resulting in the minimum speckle noise in the image, the respective part or the respective feature of the image. | 01-26-2012 |
20120146844 | ACTIVE RADAR SYSTEM AND METHOD - The present invention relates to an active radar system and a corresponding method. The proposed system comprises at least two transmit antennas that each transmits radiation to a scene as a transmit signal, said transmit signal comprising a series of frequency modulated pulses, at least one receive antenna that receives radiation from said scene as a receive signal, a controller that controls said at least two transmit antennas. The transmissions of the transmit signals are subsequently initiated with time offsets, controlled to be larger than the time delay between transmission of a first transmit signal of said two transmit signals and reception of radiation of said first transmit signal by said at least one receive antenna and to be smaller than the time duration of a complete frequency modulated pulse of said first transmit signal. | 06-14-2012 |
20130208824 | PILOT PATTERN DESIGN FOR A STTD SCHEME IN AN OFDM SYSTEM - A transmitting device for transmitting data symbols and pilot symbols in an OFDM transmission system; the device comprising symbol generating means for generating said data symbols and said pilot symbols, means for transmitting said data symbols and pilot symbols respectively by using a plurality of subcarriers of said OFDM transmission system, wherein said symbol generating means is designed to selectively generate a first type pilot symbol and a second type pilot symbol being orthogonal to said first type pilot symbol so that a pilot symbol pattern in the frequency dimension comprises at least said first type pilot symbol to be transmitted by using a predefined subcarrier and second type pilot symbol to be transmitted by using other predefined subcarrier, and wherein said pilot symbol pattern has a different pattern from a succeeding pilot symbol pattern in time dimension. | 08-15-2013 |