Patents by Inventor Johan Axnäs
Johan Axnäs 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).
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Publication number: 20110038405Abstract: A communication method for use in a first cellular communications system is proposed for minimizing the interference caused by strong interfering pulses in the same frequency band as the system or an adjacent frequency band. The method comprises the steps of receiving an incoming signal bandpass filtering the incoming signal to filter out a first frequency band (B1) used by the communications system and forwarding the bandpass filtered signal to a receiver unit (35) for processing and forwarding the processed signal to a signal detector (37) arranged to detect the wanted signal. Redirecting a fraction of the received signal and detecting the power of the redirected fraction. Using the detected power to modify the function of the signal detector (37).Type: ApplicationFiled: April 8, 2008Publication date: February 17, 2011Inventors: Johan Axnas, Vimar Bjork, Markus Ringstrom
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Publication number: 20100296608Abstract: The present invention aims to provide a method for fast and exact ML low-complexity demodulation in for example MIMO systems. The present invention relates to a method and arrangement for processing signals, especially a Maximum Likelihood (ML) demodulation of Quadrature Amplitude Modulation (QAM) signals, in a digital communications system, having a number of transmit antennas transmitting nT symbols, the method comprises the steps of: using xm, denoting symbols transmitted, wherein m=1 . . . nT, given a channel, selecting i and j and making pre-calculations facilitating finding a best combination of Xl . . . Xi?1, Xi+1 . . . Xj?1, Xj+1 . . . XnT for any given Xi, Xj and a received signal, going through every combination X1 . . . Xi?1, Xi+1 . . . Xj?1, Xj+1 . . . XnT and projecting in a number of directions for each of said combinations and generating a list of candidate combinations of Xi and Xj for each combination X1 . . . Xi?1, Xi+1 . . . Xj?1, Xj+1 . . .Type: ApplicationFiled: July 7, 2006Publication date: November 25, 2010Inventor: Johan Axnäs
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Publication number: 20100239044Abstract: The effects of interference between a communication system operating in a frequency area and another system sending out pulses affecting the frequency area can be handled by means of a of pulses communication unit (RBS1, MT1) for use in a first cellular communications system, in which at least one type of system sensitive data is transmitted at pre-determined points in time, said communications unit comprising transmitting means (14, 24) arranged to transmit said system sensitive data and processing means (11, 21) arranged to control the transmitting means to transmit the system sensitive data at new points in time different from the predetermined points in time, instead of at said predetermined points in time, to reduce the risk of interference from a second system operating in the same frequency range as the first cellular communications system.Type: ApplicationFiled: April 14, 2008Publication date: September 23, 2010Inventors: Markus Ringstrom, Johan Axnas, Robert Baldemair
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Publication number: 20100238894Abstract: Interference between a communication system operating in a frequency area and another system sending out pulses affecting the frequency area can be handled by means of a communication unit (RBS 1. MT1) for use in a cellular communications system, said communications unit comprising detecting means (10, 20) for determining the presence of at least one interfering pulse from another system affecting the signalling in the cellular communications system, and processing means (11, 21) for selecting and taking appropriate action based on the detected at least one interfering pulse.Type: ApplicationFiled: April 14, 2008Publication date: September 23, 2010Inventors: Markus Ringstrom, Johan Axnas, Sverker Magnusson
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Publication number: 20100075685Abstract: A scheduling algorithm is disclosed that allows mobile units, participating in an ongoing communications session, to temporary perform channel-demanding communications operations without ending the session and that is useful in the case of no free radio channels. The algorithm is based on selecting a radio channel for transmitting a radio block based on information of a previous radio channel, no which a previous radio block has been transmitted. The radio block and the previous radio block are based on common information. A mobile unit participating in the communications session selects whether to perform any channel-demanding communications operations on the selected radio channel. By limiting any such other channel-demanding operations to only the selected radio channel, the probability of loss of useful data for the mobile unit during the communications session is minimized.Type: ApplicationFiled: May 11, 2005Publication date: March 25, 2010Inventor: Johan Axnäs
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Patent number: 7542443Abstract: Keeping track of potential receive window positions in a communication system can prevent the receive window from moving from the proper potential positions, thereby reducing the probability of incorrect positions of the receive window. For example, a receive window can be updated by comparing the block number of a received block to a receive window; if the block number of the received block is outside the receive window, discarding the received block; if the block number of the received block is inside the receive window, retaining the received block; and determining an updated receive window that has a reduced size that excludes received blocks having block numbers that are not permitted according to the sequence of block numbers.Type: GrantFiled: August 30, 2005Date of Patent: June 2, 2009Assignee: Telefonaktiebolaget L M Ericsson (publ)Inventors: Jakob Singvall, Johan Axnäs
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Publication number: 20090109902Abstract: The object of the present invention is to provide a mechanism for a more efficient carrier search. The object is achieved by a method for sending a signal in a first node. The first node communicates with a second node via radio communication, which radio communication is performed by multi carrier transmission. The first node uses a carrier, being associated with a frequency range. The method comprises the step of transmitting an end-marker signal within or close to the frequency range. The end-marker signal is intended to be received and used by the second node for identifying the frequency range of the used carrier.Type: ApplicationFiled: May 19, 2006Publication date: April 30, 2009Inventors: Johan Axnas, Niklas Johansson, Johan Nystrom, Per Skillermark, Kai-Erik Sunell
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Patent number: 7471928Abstract: The invention involves selection of modulation scheme for a mobile unit (100) having access to a link quality enhancing algorithm (130) operable only on data modulated using a subset of the available modulation schemes. The mobile unit (100) performs signal quality measurements on a communications link (410), over which data modulated with a first modulation scheme is communicated. A link quality measure is then determined for this first modulation. A quality enhancement due to operation of the algorithm (130) is also determined. This quality measure and the quality enhancement are used for generating decision information, which is reported to the network (200). There the information is used for estimating link quality measure(s) of currently non-employed modulation(s) for the mobile unit (100). The selection of a modulation scheme for the communications link is then performed based on the decision information and the estimated quality measure(s).Type: GrantFiled: June 1, 2004Date of Patent: December 30, 2008Assignee: Telefonaktiebolaget LM Ericsson (publ)Inventors: Johan Axnas, Stephen Craig, Dayong Chen, Stefan Eriksson
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Publication number: 20080318612Abstract: Peer-to-peer communication between user terminals in a licensed spectrum is enabled by a method comprising the following steps: —communicating directly, peer-to-peer, between the first and the second mobile terminal, and —disconnecting the peer-to-peer communication in dependence of control signals received or not received from the base station. Thus, according to the invention, the network is enabled to control the peer-to-peer communication between two user terminals.Type: ApplicationFiled: November 11, 2005Publication date: December 25, 2008Inventors: Johan Axnas, Anders Furuskar, Peter de Bruin
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Publication number: 20080274727Abstract: Signal properties of a signal section (106) comprising a training sequence are compared with corresponding signal properties of other signal sections (108, 110). At a too large discrepancy, co-sequence interference is concluded to be present. The used signal property can preferably be a signal-to-noise ratio measure or a signal statistics measure. If the existence of co-sequence interference (102) is concluded, measures can be taken to avoid such interference and to mitigate the effects of the interference. A method for mitigating effects of co-sequence interference in channel estimation comprises a joint detection and estimation procedure performed under constrictions assuming presence of co-sequence interference.Type: ApplicationFiled: June 18, 2004Publication date: November 6, 2008Applicant: TELEFONAKTIEBOLAGET LM ERICSSONInventors: Johan Axnas, Magnus Olsson, Dennis Hui
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Publication number: 20080232340Abstract: When transmitting data from a transmission unit to a reception unit over a channel in a wireless communication system, it has been observed that there are inherent losses in throughput, especially for a channel experiencing high channel quality variations over its frequency range. To improve the throughput over such a channel, it is proposed to: estimate the quality of each subchannel of a channel, classify the subchannels into a number of quality groups based on the estimated quality, and select a code rate per quality group. This selected code rate per quality group is then used when a data word to be transmitted is coded. Simulations have shown that by grouping the subchannels into a limited number of groups, for example one to four groups depending on the channel quality variation, a high throughput could be achieved with a minimum of signaling cost in the form of extra overhead.Type: ApplicationFiled: November 4, 2005Publication date: September 25, 2008Inventors: Lei Wan, Johan Axnas
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Publication number: 20080214169Abstract: A method for comparing configurations in a telecommunication system comprises switching S1, S3 between two or more configurations, and for each configuration measuring S2, S4 some predetermined parameter. The switching and measuring steps are repeated at least one time during a predetermined time period. For each of the configurations the collected measurements are statistically evaluated S5. Subsequently, the evaluated parameters and consequently the configurations can be compared S6.Type: ApplicationFiled: May 26, 2005Publication date: September 4, 2008Applicant: Telefonaktiebolaget LM Ericsson (publ)Inventors: Johan Axnas, Benny Lennartson
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Patent number: 7421261Abstract: The present invention relates to a blind detection of a received signal having at least one property, which initially is unknown to the receiver, however, limited to a finite set of alternatives ({p1, p2, . . . , pm}). According to the invention, the unknown property is automatically identified as follows. A respective quality measure (q1, q2, . . . , qm) is derived from the incoming signal (r(n)), which each represents a particular property in the finite set of alternatives ({p1, p2, . . . , pm}). The quality measures (q1, q2, . . . , qm) are obtained according to a procedure that involves a computationally efficient rejection of any unwanted signal components in the incoming signal (r(n)). Then, the quality measures (q1, q2, . . . , qm) are compared with each other in order to find a quality measure, which best fulfills a blind selection criterion. The quality measure (qi) thus obtained corresponds to the initially unknown property (pi).Type: GrantFiled: April 24, 2002Date of Patent: September 2, 2008Assignee: Telefonaktiebolaget L M Ericsson (PUBL)Inventors: Henrik Sahlin, Johan Axnäs, Andreas Hedberg
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Publication number: 20080186976Abstract: The invention provides a scheduling of data blocks on multiple data carriers and a selection of data carrier to listen to. A transmitting unit simultaneously transmits, during a communication session with at least one participating receiving unit, at least a first data block on a first data carrier and a second data block on a second data carrier. The receiving unit selects which of these data carriers to listen to, i.e. whether to receive the first or second data block, based on a reception quality of a previously received data block. Furthermore, at least one of the first and second data block is based on information common to the data block and the previous data block, e.g. the first or second data block could be re-transmitted version of the previous block.Type: ApplicationFiled: May 11, 2005Publication date: August 7, 2008Applicant: Telefonaktiebolaget LM Ericsson (PUBL)Inventors: Johan Axnas, Tobias Tynderfeldt
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Patent number: 7225382Abstract: The invention relates to incremental redundancy operation, and a basic idea of the invention is to provide an extended acknowledgment feedback, for each of a number of data blocks, from the receiving side to the transmitting side to enable indication whether any soft information associated with at least one sub-block of the data block has been stored in memory at the receiving side. This information helps the transmitter to select which of the data blocks that may be suitable to retransmit next. For example, by first retransmitting data blocks for which one or more sub-blocks are already stored in the receiver memory, the probability of successful decoding of these data blocks increases, and thus the corresponding sub-blocks can be removed from memory, allowing room for sub-blocks of new data blocks. This significantly improves the utilization of the memory on the receiving side, increases throughput and reduces delay.Type: GrantFiled: May 4, 2004Date of Patent: May 29, 2007Assignee: Telefonakiebolaget LM Ericsson (publ)Inventors: Rajaram Ramech, Jacob Singvall, Johan Axnäs, Tomas Jönssonl
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Publication number: 20060182057Abstract: Keeping track of potential receive window positions in a communication system can prevent the receive window from moving from the proper potential positions, thereby reducing the probability of incorrect positions of the receive window. For example, a receive window can be updated by comparing the block number of a received block to a receive window; if the block number of the received block is outside the receive window, discarding the received block; if the block number of the received block is inside the receive window, retaining the received block; and determining an updated receive window that has a reduced size that excludes received blocks having block numbers that are not permitted according to the sequence of block numbers.Type: ApplicationFiled: August 30, 2005Publication date: August 17, 2006Inventors: Jakob Singvall, Johan Axnas
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Publication number: 20050249296Abstract: The invention is based on the recognition that optimal or at least improved performance can be obtained by providing relevant information that enables selection of which sub-block to set forth for transmission from the transmitting side to the receiving side. The idea according to the invention is to measure, for at least one data block, the reception quality of a number of received sub-blocks, and select which sub-block to set forth for transmission from the transmitting side based on the measured sub-block reception quality. For example, when all or several sub-blocks of a given data block have been received but the data block can still not be successfully decoded, it would normally be best to retransmit the sub-block that has the lowest quality. This generally increases the probability of successful decoding of the data block, thus increasing the throughput and reducing the delay.Type: ApplicationFiled: May 4, 2004Publication date: November 10, 2005Applicant: Telefonaktiebolaget LM Ericsson (publ)Inventors: Johan Axnas, Tomas Jonsson, Rajaram Ramesh, Jakob Singvall
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Publication number: 20050251721Abstract: The invention relates to incremental redundancy operation, and a basic idea of the invention is to provide an extended acknowledgment feedback, for each of a number of data blocks, from the receiving side to the transmitting side to enable indication whether any soft information associated with at least one sub-block of the data block has been stored in memory at the receiving side. This information helps the transmitter to select which of the data blocks that may be suitable to retransmit next. For example, by first retransmitting data blocks for which one or more sub-blocks are already stored in the receiver memory, the probability of successful decoding of these data blocks increases, and thus the corresponding sub-blocks can be removed from memory, allowing room for sub-blocks of new data blocks. This significantly improves the utilization of the memory on the receiving side, increases throughput and reduces delay.Type: ApplicationFiled: May 4, 2004Publication date: November 10, 2005Applicant: Telefonaktiebolaget LM Ericsson(publ)Inventors: Rajaram Ramesh, Jakob Singvall, Johan Axnas, Tomas Jonssonl
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Publication number: 20050159166Abstract: A quality of service profile for a mobile communication subscriber unit is determined and includes one or more mobile-specific desired quality of service parameters. Actual values for the service parameter(s) is(are) determined and fed back to a link quality controller to determine whether they are in an acceptable range or relationship with corresponding actual quality of service parameter values. A modulation and/or coding scheme for transmitting the information over the radio link is selected or adjusted based on whether the desired and actual quality of service parameters are in an acceptable range or acceptable relationship. A combined “desired” quality of service parameter using the first and second quality of service parameters (or more if desired) may be determined. A combined “actual” quality of service parameter using first and second actual quality service parameter values is determined.Type: ApplicationFiled: January 21, 2004Publication date: July 21, 2005Applicant: Telefonaktiebolaget LM Ericsson (publ)Inventors: Tomas Jonsson, Ylva Timner, Peter de Bruin, Johan Axnas
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Publication number: 20040156448Abstract: The present invention relates to a blind detection of a received signal having at least one property, which initially is unknown to the receiver, however, limited to a finite set of alternatives ({p1, p2, . . . , pm}). According to the invention, the unknown property is automatically identified as follows. A respective quality measure (q1, q2, . . . , qm) is derived from the incoming signal (r(n)), which each represents a particular property in the finite set of alternatives ({p1, p2, . . . , pm}). The quality measures (q1, q2, . . . , qm) are obtained according to a procedure that involves a computationally efficient rejection of any unwanted signal components in the incoming signal (r(n)). Then, the quality measures (q1, q2, . . . , qm) are compared with each other in order to find a quality measure, which best fulfils a blind selection criterion. The quality measure (qi) thus obtained corresponds to the initially unknown property (pi).Type: ApplicationFiled: November 24, 2003Publication date: August 12, 2004Inventors: Henrik Sahlin, Johan Axnas, Andreas Hedberg