Abstract: A method for mitigating inter-mode interference (IMI) caused by antenna misalignment in an orbital angular momentum (OAM) mode multiplexing (OAM-MM) system and detecting a signal in an OAM beam. The method includes receiving an OAM beam bearing a signal, determining a phase-shifting value based on at least one of a type of the antenna misalignment and one or more antenna-misalignment parameters, wherein the phase-shifting value belongs to a beamforming (BF) codebook, shifting the phase of the received OAM beam using the determined phase-shifting value, and detecting the signal from the phase-shifted OAM beam.

Abstract: A method for mitigating inter-mode interference (IMI) caused by antenna misalignment in an orbital angular momentum (OAM) mode multiplexing (OAM-MM) system and detecting a signal in an OAM beam. The method includes receiving an OAM beam bearing a signal, determining a phase-shifting value based on at least one of a type of the antenna misalignment and one or more antenna-misalignment parameters, wherein the phase-shifting value belongs to a beamforming (BF) codebook, shifting the phase of the received OAM beam using the determined phase-shifting value, and detecting the signal from the phase-shifted OAM beam.

Abstract: A method of beam steering is provided to address the squint effect that occurs in phased array antennas when wideband signals are transmitted. Beam steering weights are computed based on an optimization that takes into account performance at a set of frequencies across a bandwidth of interest, including at least endpoints of the bandwidth, and a design frequency.

Abstract: Some aspects of the present disclosure relate to detection of a Phase Hit and, upon detecting the Phase Hit, determining the magnitude and location of the Phase Hit. Detecting the Phase Hit may involve comparing a phase offset difference for successive pilot symbol to a detection threshold. Determination of the detection threshold may involve a Neyman-Pearson binary hypothesis testing (NP-BHT) approach. Once the magnitude and location of the Phase Hit are known, data symbols received after the location may be processed to remove the magnitude of the Phase Hit.

Abstract: A method of beam steering is provided to address the squint effect that occurs in phased array antennas when wideband signals are transmitted. Beam steering weights are computed based on an optimization that takes into account performance at a set of frequencies across a bandwidth of interest, including at least endpoints of the bandwidth, and a design frequency.

Abstract: Some aspects of the present disclosure relate to detection of a Phase Hit and, upon detecting the Phase Hit, determining the magnitude and location of the Phase Hit. Detecting the Phase Hit may involve comparing a phase offset difference for successive pilot symbol to a detection threshold. Determination of the detection threshold may involve a Neyman-Pearson binary hypothesis testing (NP-BHT) approach. Once the magnitude and location of the Phase Hit are known, data symbols received after the location may be processed to remove the magnitude of the Phase Hit.

Abstract: Phase noise (PN) is suppressed in an OFDM signal. In an initial iteration, an estimation of the PN samples in an OFDM signal vector is produced and the OFDM signal is demodulated using the initial estimation of the PN to generate constellation symbols for the initial iteration. In an additional iteration, an Inverse Fast Fourier Transform of constellation symbols generated in a preceding iteration is calculated to reconstruct preceding samples of the transmitted signal vector. A PN effect on the reconstructed samples is estimated. A next estimation of the PN in a next signal vector is produced based on the estimated PN effect on the reconstructed samples. The next signal vector is demodulated using the next estimation of the PN to generate constellation symbols for the additional iteration. A predetermined maximum number of additional iterations may be used.