Patents by Inventor Ali S. Khayrallah

Ali S. Khayrallah 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).

  • Publication number: 20160248615
    Abstract: A frequency deviation estimator (20, 40) estimates an instantaneous frequency deviation in a received signal that includes pilot sub-blocks non-contiguously distributed in time across a radio block. Each pilot sub-block comprising one or more pilot symbols. The estimator (20, 40) is configured to select, from the pilot sub-blocks non-contiguously distributed in time across the radio block, a particular pilot sub-block for which to obtain an instantaneous frequency deviation estimate. The estimator (20, 40) applies a Fast Fourier Transform (FFT) or a Discrete Fourier Transform (DFT) to a set of contiguous received signal samples that spans multiple ones of the pilot sub-blocks, including the particular pilot sub-block as well as one or more assisting pilot sub-blocks neighboring that particular pilot sub-block. The estimator (20, 40) then obtains an instantaneous frequency deviation estimate for the particular pilot sub-block based on the resulting FFT or DFT outputs.
    Type: Application
    Filed: May 6, 2015
    Publication date: August 25, 2016
    Inventors: Yi-Pin Eric Wang, Bo Hagerman, Ali S. Khayrallah, Michael Samuel Bebawy, Leif Wilhelmsson
  • Patent number: 9397819
    Abstract: According to one or more embodiments described and claimed herein, HARQ acknowledgements, re-transmissions, and related signaling (e.g., channel quality reports) are performed on a Re-transmission Extension Carrier (REC) separate from the primary downlink traffic carrier(s). In various embodiments, as explained herein, the REC may comprise an aggregated wireless communication network channel, which may be cross-channel scheduled or may have its own scheduler. The REC may be Frequency Domain Duplex (FDD) or Time Domain Duplex (TDD). The REC may be dedicated to a main downlink carrier, or may be shared across a plurality of aggregated component carriers. The REC may be transmitted from the same base station as one or more associated main carriers, or from a different base station. A shared REC may be operated in cooperative or contention modes. The REC may be implemented in unlicensed spectrum.
    Type: Grant
    Filed: October 2, 2012
    Date of Patent: July 19, 2016
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Ali S. Khayrallah, Jung-Fu Cheng
  • Patent number: 9363002
    Abstract: A system and method in which a base station treats the Channel State Information (CSI) from wireless terminals as only partially-stale, and exploits this partially-stale CSI to predict the current channel from old estimates of the channel. The predicted channel is then used to design a precoder. The base station shapes the transmitted signal with the precoder so as to match it as closely as possible to the current channel. Particular embodiments thus combine the benefits of the stale feedback scheme with precoding to match the channel. Consequently, the signal received at a terminal is better conditioned, thereby providing a greater overall boost in performance of the communication arrangement between the base station and the terminal. The usage of partially-stale CSI can be important for dense networks with a large number of simple terminals.
    Type: Grant
    Filed: March 8, 2012
    Date of Patent: June 7, 2016
    Assignee: TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
    Inventors: Ali S. Khayrallah, Yi-Pin Eric Wang
  • Patent number: 9357432
    Abstract: A system and method for media streaming in a scenario where very high bitrate wireless service is available within a macro cell through small cells. When a mobile device is in a small cell, a base station may download the multimedia content onto the mobile device at the high bitrate instead of streaming the content at a low bitrate. The mobile device cannot misuse the content made available through the download because its ability to de-scramble the downloaded information is made time dependent by a two-stage scrambling process at the base station that keeps the information scrambled until it is ready to be consumed. The base station withholds from the mobile device information related to de-scrambling of the received content until the appropriate time. Such withheld information includes time-varying decryption keys, which control the timing of decryption and are supplied to the mobile device in a temporally sequential manner.
    Type: Grant
    Filed: June 2, 2014
    Date of Patent: May 31, 2016
    Assignee: Telefonaktiebolaget L M Ericsson (Publ)
    Inventor: Ali S. Khayrallah
  • Publication number: 20160135082
    Abstract: A delegate wireless terminal can receive and store messages sent to it by a receiving network node. The wireless terminal can identify a message label based on a mapping for the received message. A transmitting network node can transmit a message label to a receiving network node across a backhaul link. The receiving network node can transmit a message label to the wireless terminal. The wireless terminal can identify a stored message that corresponds to the received message label, and send the corresponding message to the receiving network node. The receiving network node can then transmit the message to its intended destination.
    Type: Application
    Filed: August 21, 2014
    Publication date: May 12, 2016
    Inventor: Ali S. Khayrallah
  • Publication number: 20160043856
    Abstract: According to some embodiments, a secondary network node detects a first data transmission of media content from a primary network node to a first wireless device. The first data transmission has a first data quality description D(n1) and a first transport format T(k1). The secondary network node selects a second data quality description D(n2?) and a second transport format T(k2?) for a second data transmission. The second data quality description D(n2?) and second transport format T(k2?) differ from the first data quality description D(1) and first transport format T(k1), respectively. The secondary network node transmits the second data transmission to a second wireless device according to the second data quality description D(n2?) and the second transport format T(k2?). The second data transmission includes at least a portion of the media content.
    Type: Application
    Filed: August 5, 2014
    Publication date: February 11, 2016
    Inventor: Ali S. Khayrallah
  • Publication number: 20150358184
    Abstract: Systems and methods related to improved coherent demodulation and, in particular, improved channel equalization that accounts for variation in an effective channel estimation error with transmitted symbols are disclosed. In one embodiment, a wireless node includes a receiver front-end, a channel estimator, and an equalizer. The receiver front-end is adapted to output samples of a received signal. The channel estimator is adapted to estimate a channel between a transmitter of the received signal and the wireless node based on the samples of the received signal. The equalizer is adapted to process the samples of the received signal according to a modified equalization scheme that compensates for variation in an effective channel estimation error with transmitted symbols to thereby provide corresponding bit or symbol decisions. In this manner, channel equalization is improved, particularly for a wireless system that utilizes a modulation scheme with varying amplitude.
    Type: Application
    Filed: June 10, 2014
    Publication date: December 10, 2015
    Inventor: Ali S. Khayrallah
  • Publication number: 20150358116
    Abstract: Systems and methods for improved coherent demodulation that account for variation of an effective channel estimation error with transmitted symbols are provided. In one embodiment, a wireless node includes a receiver front-end, a channel estimator, and a soft-value processor. The receiver front-end is adapted to output samples of a received signal. The channel estimator is adapted to estimate a channel between a transmitter of the received signal and the wireless node based on the samples of the received signal. The soft-value processor is adapted to process the samples of the received signal according to a soft-value generation scheme that accounts for variation of an effective channel estimation error with transmitted symbols to thereby provide corresponding soft values. By accounting for the variation of the effective channel estimation error with transmitted symbols, the soft-value processor provides improved performance, particularly in a low Signal-to-Noise Ratio (SNR) scenario.
    Type: Application
    Filed: June 10, 2014
    Publication date: December 10, 2015
    Inventors: Ali S. Khayrallah, Jung-Fu Cheng
  • Publication number: 20150350947
    Abstract: A system and method for media streaming in a scenario where very high bitrate wireless service is available within a macro cell through small cells. When a mobile device is in a small cell, a base station may download the multimedia content onto the mobile device at the high bitrate instead of streaming the content at a low bitrate. The mobile device cannot misuse the content made available through the download because its ability to de-scramble the downloaded information is made time dependent by a two-stage scrambling process at the base station that keeps the information scrambled until it is ready to be consumed. The base station withholds from the mobile device information related to de-scrambling of the received content until the appropriate time. Such withheld information includes time-varying decryption keys, which control the timing of decryption and are supplied to the mobile device in a temporally sequential manner.
    Type: Application
    Filed: June 2, 2014
    Publication date: December 3, 2015
    Applicant: TELEFONAKTIEBOLAGET L M ERICSSON (PUBL)
    Inventor: Ali S. Khayrallah
  • Publication number: 20150318962
    Abstract: According to some embodiments, a method for handling packet retransmissions is implemented by a secondary network node and includes detecting a first data transmission from a first primary network node to a wireless device. A first response message from the first wireless device to the first primary network node is then detected. The response message indicates that the first data transmission included an error when received by the wireless device. A second data transmission from the secondary network node to the first wireless device is detected. The second data transmission from the secondary network node includes at least a portion of the first data transmission from the first primary network node.
    Type: Application
    Filed: May 2, 2014
    Publication date: November 5, 2015
    Applicant: Telefonaktiebolaget L M Ericsson (publ)
    Inventor: Ali S. Khayrallah
  • Patent number: 9078276
    Abstract: Devices and methods for scheduling and interference cancellation that consider the interference cancellation capability of user equipment (UEs) are disclosed. Using reduced-rate sub-frame (or resource block) strategies, the transmission data rate to a scheduled user in a given cell may be reduced to ensure effective interference cancellation performance at the receiver of a co-scheduled user in another cell. By taking advantage of interference mitigation at one or more terminals, a scheduler may improve network spectral efficiency compared to existing inter-cell interference cancellation schemes, including almost blank sub-frame (ABS), further enhanced inter-cell interference coordination (FeICIC), and other resource partitioning schemes, such as reduced power sub-frames or frequency domain resource partitioning.
    Type: Grant
    Filed: November 13, 2012
    Date of Patent: July 7, 2015
    Assignee: TELEFONAKTIEBOLAGET L M ERICSSON (PUBL)
    Inventors: Yi-Pin Eric Wang, Jung-Fu Cheng, Stephen Grant, Ali S. Khayrallah
  • Publication number: 20150140943
    Abstract: A multiple antenna receiver receives a wideband signal containing two or more sub-signals of interest. The receiver may be selectively configured to receive all sub-signals of interest with all antennas, or to receive different sub-signals of interest with different antennas.
    Type: Application
    Filed: January 28, 2015
    Publication date: May 21, 2015
    Inventor: Ali S. Khayrallah
  • Patent number: 8953660
    Abstract: Devices and methods for providing a pilot structure for a virtual diversity receiver (VDR) scheme are disclosed. In order to improve the performance of a communication network, a VDR scheme is implemented to facilitate the exchange of information between user devices via an intermediary device, such as a base station. The pilot structure supports estimation of channel parameters at the receivers, including true channel taps, as well as estimations of the virtual channels created by the VDR scheme in order to enable the use of receive-diversity signal processing techniques.
    Type: Grant
    Filed: October 2, 2012
    Date of Patent: February 10, 2015
    Assignee: Telefonaktiebolaget L M Ericsson (PUBL)
    Inventors: Ali S. Khayrallah, Yi-Pin Eric Wang
  • Patent number: 8948138
    Abstract: A compression/decompression method for backhaul communication of a complex-valued radio signal between base stations and the network processing unit, such as a Central Processor of a Coordinated MultiPoint (CoMP) system, significantly reduces backhaul bandwidth. The spatial and temporal correlations of the wireless IQ signal are exploited in order to remove redundancy and substantially reduce signal bandwidth. Feature component signals of significance are extracted through linear transformation to form the radio signal, and are individually quantized, possibly at different bit rates in accordance with their relative importance. The transformation can either be pre-determined or computed in real-time based on the spatial and temporal statistics of the radio signal. In the latter case, the transformation matrix or matrices are also sent over the backhaul in order to allow the radio signal to be reconstructed at the receiving end. Different methods of generating the transformation matrices are proposed.
    Type: Grant
    Filed: March 23, 2011
    Date of Patent: February 3, 2015
    Assignee: Telefonaktiebolaget L M Ericsson (Publ)
    Inventors: Dennis Hui, Jung-Fu Cheng, Jiann-Ching Guey, Ali S. Khayrallah, Shing-Wa Wong
  • Patent number: 8848773
    Abstract: Devices and methods for determining transmission rates based on a virtual diversity receiver (VDR) scheme are disclosed. Performance is improved through determination of appropriate transmission rates, which are determined based on one or more signal to interference plus noise ratios (SINRs). The SINRs are calculated using virtual noise and channel coefficient values obtained as part of the VDR scheme. Utilizing an underlying pilot structure a user device may receive several sets of symbols. These symbols are then used to obtain both real and virtual channel noise power values and channel coefficients. These values and coefficients are then used to determine first and second SINR values indicative of one or more channels in the communication network. These SINR values may correlate to transmission rates (modulation order and/or coding rate). The SINRs may be sent to a base station, or the user device itself may determine one or more transmission rates.
    Type: Grant
    Filed: October 2, 2012
    Date of Patent: September 30, 2014
    Assignee: Telefonaktiebolaget L M Ericsson (Publ)
    Inventors: Ali S. Khayrallah, Yi-Pin Eric Wang
  • Patent number: 8804883
    Abstract: A method and apparatus carry out received signal processing for received communication signals based on least squares processing to estimate the contribution of one or more interferer signals. The exemplary receiver uses interferer signal channel estimates to obtain least squares estimates for the interference contributions of one or more interferer signals, and then uses those estimates to suppress interference during demodulation processing. Further, the least-squares estimates may be used to obtain a reduced search space wherein the candidate set of signals searched during demodulation processing is reduced.
    Type: Grant
    Filed: June 8, 2004
    Date of Patent: August 12, 2014
    Assignee: Telefonaktiebolaget LM Ericsson (Publ)
    Inventor: Ali S. Khayrallah
  • Patent number: 8798215
    Abstract: Demodulation methods and apparatus for a multi-stage SLI demodulator are disclosed. Residual signals from each demodulation stage are modeled as finite sets of unresolved signals and a new metric is introduced for use in search of best candidate symbol estimates. The metric may be evaluated based on a probability distribution function of the residual signals or a probability mass function of the unresolved signals. The metric may also be approximated by the sum of a conventional Euclidean metric and a correction metric. The best candidate symbol estimates generated from each stage of the multi-stage SLI demodulator are summed to form cumulative symbol estimates.
    Type: Grant
    Filed: November 29, 2011
    Date of Patent: August 5, 2014
    Assignee: Telefonaktiebolaget L M Ericsson (Publ)
    Inventors: Ali S. Khayrallah, Dennis Hui
  • Patent number: 8750860
    Abstract: A system and method in which two base stations—a Primary Base Station (PBS) and a Secondary Base Station (SBS)—are used to accomplish a Virtual 2-antenna Receiver (V2RX) scheme. The PBS may perform the initial transmissions of symbols, but, instead of the PBS, the SBS may handle the subsequent reception of terminal-specific Channel State Information (CSI) and the broadcast of an additional signal. The SBS can be much simpler in design than the PBS, and can be located physically closer to the terminals, requiring less power for the feedback signals (from the terminals) and also for SBS's own broadcast of the additional signal to terminals. The reception and usage of stale CSI using a secondary base station can be important for dense networks with a large number of simple terminals. Because of the rules governing abstracts, this abstract should not be used to construe claims.
    Type: Grant
    Filed: December 1, 2011
    Date of Patent: June 10, 2014
    Assignee: Telefonaktiebolaget L M Ericsson (Publ)
    Inventor: Ali S. Khayrallah
  • Patent number: 8750913
    Abstract: With the asymmetric resource sharing disclosed herein, a base station transmits fewer information symbols at some transmission times to one or more mobile terminals than to other mobile terminals at other transmission times. After transmitting the information symbols, the base station receives channel estimates from the mobile terminals, which the base station then use to generate synthesized signals representing estimates of the signals received at the mobile terminals. The base station subsequently combines complementary pairs of the synthesized signals to generate combined signals and transmits at least one of the combined signals to implement at least one virtual antenna for at least one of the mobile terminals.
    Type: Grant
    Filed: December 13, 2011
    Date of Patent: June 10, 2014
    Assignee: Telefonaktiebolaget L M Ericsson (Publ)
    Inventors: Ali S. Khayrallah, Yi-Pin Eric Wang
  • Patent number: 8743942
    Abstract: A receiver includes a constellation processing module and a plurality of demodulation stages. The constellation processing module groups points of a constellation associated with a transmitted signal into a plurality of subsets, were at least two adjacent ones of the subsets have one or more common constellation points so that the at least two adjacent subsets overlap. The constellation processing module also determines a centroid-based value for each of the subsets of constellation points and groups the centroid-based values into one or more sets. Each of the demodulation stages except for the last demodulation stage localizes a search for a final symbol decision using the set of centroid-based values input to or selected by the demodulation stage as constellation points. The last demodulation stage determines the final symbol decision using the subset of constellation points input to or selected by the last demodulation stage.
    Type: Grant
    Filed: October 4, 2012
    Date of Patent: June 3, 2014
    Assignee: Telefonaktiebolaget L M Ericsson (Publ)
    Inventor: Ali S. Khayrallah