Patents by Inventor Krishnavelan Sivaraman

Krishnavelan Sivaraman 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: 10212679
    Abstract: The propagation channel in a wireless communication system may be characterized as a multipath fading model wherein the multiple delayed and attenuated versions of the transmitted signal are received. In the receiver's processing chain, the impairments introduced by this propagation channel may be equalized using the channel estimates. The channel estimation is mainly performed using the known reference signals by conventional methods. The estimation of delay spread profile may be crucial for high performance channel estimation. The conventional methods may be appropriate for high operating channel bandwidths. In the case of low channel bandwidth, limited number of reference signals may be available which may not be adequate for accurate delay spread estimation. A method and apparatus are disclosed that improve the delay spread estimation for low channel bandwidth scenarios.
    Type: Grant
    Filed: July 22, 2016
    Date of Patent: February 19, 2019
    Assignee: MBIT WIRELESS, INC.
    Inventors: Keerthivasan Suresh, Anandhavadivel Sepperumal, Karthik Thirukannan, Krishnavelan Sivaraman
  • Patent number: 10129709
    Abstract: Fading profile detection may be used in many wireless communication system receivers to perform improved channel estimation and decoding. Delay spread may be very high for some fading profiles and hence the coherence bandwidth may be very limited for these fading profiles. It may not be possible to reliably differentiate high delay spread fading profiles from low and mid delay spread fading profiles by the conventional delay spread estimation techniques. A method and apparatus are disclosed that can identify and differentiate high delay spread fading profiles from the low and mid delay spread fading profile to perform improved channel estimation and decoding of the received data.
    Type: Grant
    Filed: July 14, 2016
    Date of Patent: November 13, 2018
    Assignee: MBIT WIRELESS, INC.
    Inventors: Krishnavelan Sivaraman, Akshayavarnikha Muthuraj, Karthik Thirukannan, Keerthivasan Suresh
  • Patent number: 9961655
    Abstract: In a wireless communication system, a client terminal may first establish time and frequency synchronization with the network. While establishing the time and frequency synchronization, a client terminal may need to detect additional parameters about the network, such as physical cell identity, before it can initiate communication with the wireless communication system. Detecting the network parameters in presence of time and frequency offsets increases the complexity of the initial cell search procedure that includes time and frequency synchronization as well as detection of network parameters. A method and apparatus are disclosed that achieve frequency synchronization earlier in the cell search procedure, which in turn reduces the complexity and improves the performance of the latter stages of cell search procedure and the overall performance of the client terminal.
    Type: Grant
    Filed: October 29, 2015
    Date of Patent: May 1, 2018
    Assignee: MBIT WIRELESS, INC.
    Inventors: Krishnavelan Sivaraman, Bhaskar Patel
  • Patent number: 9762272
    Abstract: MMSE-IRC receiver may be used to suppress inter-cell interference for improving the cell-edge user throughput in cellular wireless communication systems. But MMSE-IRC performance is limited by estimation errors, namely, channel estimation error and covariance matrix estimation error. It is important to have an accurate covariance matrix estimation scheme, so that maximum gain from MMSE-IRC receiver may be achieved. In order to have accurate estimation, covariance matrix may be averaged across channel bandwidth in frequency domain. A method and apparatus are disclosed that adaptively determine the averaging bandwidth employed for covariance matrix estimation based on the detected delay spread and SNR. Based on the present disclosure, the throughput performance of MMSE-IRC receiver may be improved by adaptively using suitable sub-band length in frequency domain averaging of covariance matrix estimation.
    Type: Grant
    Filed: July 11, 2016
    Date of Patent: September 12, 2017
    Assignee: MBIT WIRELESS, INC.
    Inventors: Karthik Thirukannan, Keerthivasan Suresh, Krishnavelan Sivaraman
  • Patent number: 9763177
    Abstract: During cell search procedure in 3GPP LTE wireless communication system it is required to detect multiple cells which may be observable by a client terminal. In conventional cell detection a client terminal may detect false cells along with true cells. The number of false cells may depend on specific conventional detection algorithm used. A method and apparatus are disclosed that use of Differential Correlation based SINR metric for filtering out false cells from the list of detected cells reported by the conventional cell detection methods. The combination of conventional cell detection and Differential Correlation SINR based false cell filtering enables significant reduction in false cells reported to the network and reduces power consumption in a client terminal.
    Type: Grant
    Filed: February 8, 2016
    Date of Patent: September 12, 2017
    Assignee: MBIT WIRELESS, INC.
    Inventors: Ganesh Baskaran, Krishnavelan Sivaraman, Bhaskar Patel
  • Patent number: 9674808
    Abstract: In a wireless communication system, a client terminal may first establish time and frequency synchronization with the network. While establishing the time and frequency synchronization, a client terminal may need to detect additional parameters about the network, such as physical cell identity, before it can initiate communication with the wireless communication system. Detecting the network parameters in presence of time and frequency offsets increases the complexity of the initial cell search procedure that includes time and frequency synchronization as well as detection of network parameters. A method and apparatus are disclosed that achieve frequency synchronization using frequency domain cross-correlation earlier in the cell search procedure, which in turn reduces the complexity and improves the performance of the latter stages of cell search procedure and the overall performance of the client terminal.
    Type: Grant
    Filed: October 21, 2015
    Date of Patent: June 6, 2017
    Assignee: MBIT WIRELESS, INC.
    Inventors: Bhaskar Patel, Krishnavelan Sivaraman
  • Patent number: 9660765
    Abstract: Low latency wireless communication applications require highly dynamic allocation of resources. Providing allocation information on a highly dynamic basis increases the overhead of control signaling for allocation. A technique known as blind decoding is used to reduce the control signaling overhead for allocation information. However, blind decoding may occasionally lead to invalid detection of allocation messages which in turn may lead to a number of problems such as wasted bandwidth, increased power consumption, reduced throughput, etc. A method and apparatus are disclosed that detect the invalid allocation messages by maintaining a record of previously received allocation messages and using it to check the validity of the newly received allocation messages.
    Type: Grant
    Filed: July 13, 2015
    Date of Patent: May 23, 2017
    Assignee: MBIT WIRELESS, INC.
    Inventors: Keerthivasan Suresh, Kirubakaran Ponnurangam, Krishnavelan Sivaraman