Prof. Bajwa Awarded U.S. Patent
Dr. Waheed Bajwa was awarded US patent 8,320,489 B2 "Determining channel coefficients in a multipath channel".
In wireless telecommunications, signals are transmitted and received over transmission channels within a limited range of frequencies, typically between 0.7 GHz to 6 GHz for domestic applications. Due to the limited amount of transmission space, it is increasingly important to perfect techniques that estimate channel state information (CSI) at the transmitter and/or receiver to maximize wireless performance over the multipath channels. In modern communication systems training-based channel learning techniques are commonly used to retrieve the CSI at the receiver, which can improve communication efficiency, particularly in terms of power and spectral efficiency.
This patent improves the accuracy of learning the receiver channel response by focusing on two critical aspects of training-based channel learning methods, sensing and estimation. Sensing relates to the design and placement of training signals that are used to probe the channel. This method defines the most suitable transmitter training signals for exploiting multipath sparsity in angle, delay and/or Doppler. Estimation refers to the signal analysis process implemented at the receiver to recover the channel response. Researchers implemented non-linear reconstruction algorithms, based on convex/linear programming, that come within a logarithmic factor of the performance of an ideal channel estimator. This new approach clearly reveals how the relationship between the training signals and the accuracy of this algorithm efficiently estimates the CSI, resulting in faster channel responses at the receiver.