Most previous works focus on single type of interference mitigation and simplified combination of these existed methods leads to high disabled probabilities of single antenna Global Navigation Satellite System (GNSS) receivers under mixed interference scenarios due to the interaction of different types of interferers. In this paper, depending on the assumption that pulsed interference repetition period is known, we introduce a segementation method which will guarantee the success of narrowband interference (NBI) power spectrum density (PSD) estimation by minimum operation in mixed interference. Then NBI and pulsed interference can be mitigated, subsequently. The effectiveness is validated by numerical simulation results.
The recently introduced compressed sensing (CS) theory can, potentially, simplify the acquisition process of resource-limited devices by taking advantage of signal sparsity. This paper proposes a perceptual-based compressed video sensing (CVS) strategy that benefits from the human visual perception properties. Two frameworks are proposed, namely, Intra-perc-CVS and Inter-perc-CVS. In both frameworks, an efficient perceptual-based weighting strategy is applied for acquisition and recovery. In the Intra-perc-CVS scheme, video frames are acquired and recovered separately, while in the Inter-perc-CVS scheme, the frames are recovered jointly to further exploit inter-frame correlation. The proposed perceptual-based frameworks show remarkable performance improvement over the standard CVS.
In this letter, we propose the demodulation method to improve the complexity of demodulation in passive MIMO (Multiple-Input Multiple-Output) scheme. This scheme uses the multiple antennas at both reader and RFID (Radio Frequency Identification) tag to increase the data-rate, but the complexity of MLD (Maximum Likelihood Detection), which is used as demodulation algorithm, increases exponentially with the number of antennas. The proposed method divides tag antennas into two groups that do not interfere each other by decoupling tag antenna groups using 180-degree hybrids at tag side and beam-forming at receiver side. Individual demodulation for each group improves the complexity of MLD significantly. Simulation results show the proposed method can reduce the complexity of MLD with degrading slight BER (Bit-Error-Rate) performance. The results reveal the proposed method is effective in reducing demodulation complexity of passive MIMO transmission even when the number of tag antennas is increased.
When a massive network disruption occurs, repair of the damaged network takes time, and the recovery process involves multiple stages. We propose a fast and traffic-balanced network recovery method that can determine an optimal recovery order of failed physical components reflecting the demand of a balance between maximizing total network flow and providing adequate logical path flows during transient recovery stages. The problem is formulated by mixed integer linear programming. The effectiveness of the proposed method was numerically evaluated, and the results show that with the proposed method, the pareto-optimal recovery order can be determined under the balance between total network flow and adequate logical path flows. In addition, the allocated minimum bandwidth of logical path is drastically improved while maximizing total network flow.
The higher beamforming gain of massive MIMO is expected to improve the link budget shortfall in higher frequency bands. We note that, in multiuser MIMO, the beamforming gain for desired terminal is also effective in overcoming inter-user interference (IUI) caused by channel time variation. Computer simulations show that the SIR performance can be improved over 20 dB by increasing the number of base station antenna elements from 2 to 100.