Patent application number | Description | Published |
20080239936 | METHOD AND APPARATUS FOR MITIGATING INTERFERENCE IN MULTICARRIER MODULATION SYSTEMS - A method and apparatus for mitigating the effect of adjacent channel interference in a multicarrier modulation system is provided. The method includes receiving an encoded signal over multiple subcarriers at different frequencies. The signal includes a plurality of pilot symbols and data symbols modulated onto the subcarriers using a modulation technique. Further, the method includes: grouping the subcarriers into multiple sets of subcarriers based on their frequencies, wherein each set includes one or more subcarriers; estimating, for each set of subcarriers, a noise value associated with at least a portion of the pilot symbols received over subcarriers included in the set; and generating a decoded signal comprising a plurality of decoded data bits, using the estimated noise values. | 10-02-2008 |
20080273633 | METHOD AND DEVICE FOR ENHANCING SIGNAL DETECTION IN A FREQUENCY SELECTIVE FADING CHANNEL - A method and system are provided for enhanced signal detection in a frequency selective fading channel. Improved signal detection is realized by replacing single matched filters with multiple matched filters. The single matched filter spectrum is partitioned by frequency into M matched filter groups, where M is a positive integer greater than one. The filter bandwidth of each of the M matched filters is less than the bandwidth of the single matched filter from which they are derived. The M matched filters are provided to filter in parallel fashion the input signal into M sub-spectrums of the signal. The input signal is filtered through the M matched filters and also sent to the energy detector. The matched filter outputs are combined and the received signal is detected using the combined output and the energy in the received signal. | 11-06-2008 |
20080320357 | METHOD AND APPARATUS FOR REDUCING SIGNALING OVERHEAD IN A COMMUNICATION SYSTEM USING HYBRID AUTOMATIC REPEAT REQUEST - A transmitting unit combines a slot identifier (SI) and a block identifier (BI) in each header that is transmitted with the data to allow a receiving unit to associate previously received data blocks with retransmissions, or retries, of the same respective data blocks in order to perform bit error detection in accordance with a hybrid or selective ARQ protocol. The receiving unit uses the SI and BI contained in the MHBKs to determine a correspondence between a retried data and a previously transmitted data block. | 12-25-2008 |
20100157959 | METHOD AND DEVICE FOR ASSIGNING TRAFFIC CHANNELS IN A WIRELESS COMMUNICATION SYSTEM - A device uses a method for assigning a traffic channel in a wireless communication system. The method includes: receiving on a control channel a first message that includes a request for a traffic channel having a traffic channel structure; determining a delay in arrival of the first message; comparing the delay in arrival to a threshold value for the traffic channel structure; and when the delay in arrival exceeds the threshold value, assigning an available traffic channel in response to the request, wherein the traffic channel has a delay tolerance that exceeds the delay in arrival. | 06-24-2010 |
20100251070 | METHOD FOR ASSIGNING AND UTILIZING FORWARD ERROR CORRECTING (FEC) CODES - An assignment scheme exploits the Media Access Control (MAC) layer protocol features under various MAC layer call scenarios. In one embodiment, the Hamming distance between pairs of critical Data Units are assigned to codewords with a minimum distance of dmin2=8 bits, thereby increasing the hard decision error correcting capability from 1 bit to 3 bits when deciding between these pairs of Data Units. The method for assigning data unit identification (DUID) codes by a radio operating within a wireless communication system includes determining by the radio whether an expected burst is a 4 Voice Burst with Encryption Synchronization Signaling (4V); when the expected burst is 4V, decoding the DUID within the received burst using an increased minimum distance; and when the expected burst is not 4V, decoding the DUID within the received burst using a minimum distance. | 09-30-2010 |
20110075771 | METHOD AND APPARATUS FOR MITIGATION OF INTERFERENCE - A method of reducing error in transmissions received in a receiver is provided. A transmission containing a synchronization signal is inputted through a first filter to a synchronization correlator, to generate a timing error of the synchronization signal. An amount of delay of the synchronization signal sufficient to reduce the timing error is determined. The transmission is delayed by the amount of delay by being passed through at least a second, variable filter whose delay is determined using a stochastic gradient algorithm. The synchronization correlator may also generate a deviation error of the synchronization signal and determine an amount of deviation correction sufficient to reduce the deviation error as well as generating a frequency error of the synchronization signal and determining an amount of frequency correction sufficient to reduce the frequency error. | 03-31-2011 |
20110075774 | METHOD AND APPARATUS FOR MITIGATION OF INTERFERENCE - A signal is provided to each of nominal, higher and lower primary filters in a receiver. The nominal, higher and lower primary filters have different center frequencies and a bandwidth B1 and bandwidths B2, respectively and a bandwidth offset B0, with B2=B1+B0. Signal recovery is performed on the output of each primary filter to obtain recovered signals and error values each associated with one of the primary filters. Each error value is provided to a secondary and tertiary filter, to generate a signal criterion, and whose output is measured to generate a quality metric, respectively, associated with each recovered signal. The recovered signal associated with the nominal primary filter and any other recovered signal having an associated signal criterion below a threshold value is selected and the selected recovered signal which has the lowest associated quality metric is chosen. | 03-31-2011 |
20110267938 | FREQUENCY DEVIATION ERROR COMPENSATION IN AN MLSE RECEIVER - A method is described to compensate for deviation error in a H-CPM sync or data burst received by a MLSE receiver in a communication device. The deviation error is estimated and matched filter coefficients are adjusted using the estimated deviation error. Metrics are determined for the current state using the adjusted matched filter coefficients. The state having the minimum metric is determined to be the most likely current state. The most likely previous state is similarly determined The burst is reconstructed backward from the last state to the initial state. The metric is the squared magnitude of the difference between the channel estimate multiplied by the matched filter coefficient associated with one of the possible states and the current state. Timing and frequency errors are compensated for before estimation and correction of the deviation error. Pilot or sync symbols are used in estimating the deviation error. | 11-03-2011 |
20120087354 | METHODS AND RECEIVERS FOR PROCESSING TRANSMISSIONS FROM TWO DIFFERENT TRANSMITTING RADIOS - A method and receiver apparatus for a receiving radio unit are disclosed for use in a wireless communication system for processing transmissions from different radio units at the receiving radio unit. A first transmitting radio unit transmits first audio information (e.g., a first audio encoded frame) in a first time slot, and a second transmitting radio unit then transmits second audio information (e.g., a second audio encoded frame) in a second time slot. The receiving radio unit receives radio frequency (RF) signals comprising a first bit stream corresponding to the first audio information, and a second bit stream corresponding to the second audio information. Based on the first bit stream and the second bit stream the receiving radio unit generates a single analog audio signal that comprises combined audio information corresponding to the first audio information and the second audio information. | 04-12-2012 |
20120106536 | METHOD AND APPARATUS FOR ACHIEVING SYNCHRONIZATION IN A WIRELESS COMMUNICATION SYSTEM - A method and apparatus for synchronizing a communication device in a communication system includes receiving a transmission from another communication device. The transmission comprises a plurality of time slots and a plurality of signaling fields inserted between the time slots. The plurality of signaling fields include a set of signaling fields of a first information type and a set of signaling fields of a second information type. The method includes detecting at least two consecutive signaling fields of the first information type, recovering a received pattern contained in a n | 05-03-2012 |
20120134353 | METHODS AND APPARATUS FOR METHOD FOR MAINTAINING A RADIO LINK AT A MOBILE RADIO - Methods and apparatus are provided for radio link maintenance at a mobile radio in a wireless communication network. The disclosed methods and apparatus help a mobile radio maintain a radio link by regularly monitoring frame synchronization, regularly checking a scrambling sequence of a mobile radio against that of infrastructure equipment, and regularly detecting and/or recovering from fade conditions. In the event the radio link can not be maintained, then the disclosed methods and apparatus will cause the mobile radio to switch to a control channel so that the synchronization, scrambling mismatch and/or fade issues may be corrected. In one implementation, the disclosed methods and apparatus can be implemented at mobile radios in an Association of Public-Safety Communications Officials (APCO) Project 25 (P25) compliant system. | 05-31-2012 |
20120135728 | METHODS FOR USING EFFECTIVE RADIATED TRANSMIT POWER OF A BASE STATION AT A WIRELESS COMMUNICATION DEVICE TO PERFORM AN AUTOMATIC ROAMING METHOD AT THE WIRELESS COMMUNICATION DEVICE - Methods, systems and apparatus are disclosed for using effective radiated transmit power of a base station at a wireless communication device to perform an automatic roaming method. In one implementation, the disclosed embodiments can be applied in a two-way wireless communication system. | 05-31-2012 |
20120135777 | METHODS FOR USING EFFECTIVE RADIATED TRANSMIT POWER OF A BASE STATION AT A WIRELESS COMMUNICATION DEVICE TO DETERMINE UPLINK TRANSMISSION RANGE AND/OR TO ADJUST TRANSMIT POWER - Methods, systems and apparatus are disclosed for using effective radiated transmit power of a base station at a wireless communication device to determine whether the wireless communication device is within uplink transmission range of the base station. The wireless communication device can also use the effective radiated transmit power to adjust transmit power at the wireless communication device and save battery resources. In one implemenation, the disclosed embodiments can be applied in a two-way wireless communication system. | 05-31-2012 |
20130016797 | METHOD AND APPARATUS FOR UPDATING SYMBOL RECOVERY PARAMETERS AND CORRECTING SYMBOL TIMING MISALIGNMENTAANM Naing; Kyaw M.AACI PlantationAAST FLAACO USAAGP Naing; Kyaw M. Plantation FL USAANM Doberstein; Kevin G.AACI ElmhurstAAST ILAACO USAAGP Doberstein; Kevin G. Elmhurst IL USAANM Han; DonghoAACI ParklandAAST FLAACO USAAGP Han; Dongho Parkland FL US - A radio receiver ( | 01-17-2013 |
20150017941 | METHOD AND APPARATUS FOR USING ERASURE TO IMPROVE SIGNAL DECODING DURING AN INTERFERENCE EVENT - A method and apparatus for using erasure to improve signal decoding when data is impacted by an interference event. Embodiments may include receiving in an RF receiver a desired on-channel signal that includes an information signal modulated on to the desired on-channel signal; generating a sampled received signal with an analog-to-digital (A/D) converter; detecting an interference event using an interference detector as well as generating a mask based on the interference event; processing the sampled received signal using the mask to generate decoding data for use by a soft decoder; and, providing the decoding data to the soft decoder. | 01-15-2015 |