Narrowband Interference Cancellation Research Articles

Narrowband Interference Cancellation using Set-membership Adaptive Predictor for GPS Receiver

The global positioning system (GPS) provides accurate positioning and timing information that is useful in various civil and military applications. The adaptive filtering predictor for GPS jamming suppression applications is proposed. This research uses the gLab-G software to substitute for the hardware receiver to record the GPS signal waveform. The normalized least-mean-square (NLMS) and set-membership NLMS (SM-NLMS) filtering methods are employed for continuous wave interference suppression. Simulation results reveal that our proposed methods can provide the better performances when the interference-to-noise ratios (INR) are varied from 20 to 50 dB. The anti-jamming performances are evaluated via extensive simulation by computing mean squared prediction error (MSPE) and signal-to-noise ratio (SNR) improvements.

Direct sequence spread spectrum communication narrowband interference cancelation in compressed domain

AbstractDue to the broad bandwidth nature of the direct sequence spread spectrum (DSSS) signal, the application of narrowband interference (NBI) cancelation algorithms based on the Nyquist‐Shannon sampling theory are limited by the high sampling rate. To solve the sampling and processing difficulty in the traditional DSSS communication interference cancelation method, we used the compressive sensing (CS) to reduce the sampling rate of the DSSS communication system, and further proposed a compressed domain NBI elimination method in this study. We proved that NBI with a certain bandwidth and DSSS signal are both sparse in specific dictionaries and proposed the corresponding sparse dictionary construction method. Detailed analysis of the compressed domain features of NBI and the DSSS signal demonstrated that it is possible to extract the strong NBI components from the compressed measurements. Two compressed domain NBI cancelation algorithms were proposed based on this idea. The extracted NBI components were filtered out from the compressed measurements directly in the first algorithm, and then we achieved the DSSS signal demodulation in compressed domain using the separated DSSS signal components with the orthogonal matching pursuit (OMP) algorithm. A proposed extraction filter block sparse Bayesian learning (EFBSBL) framework algorithm was utilized to estimate the NBI from the compressed measurements in the second algorithm. The estimated NBI was eliminated from the received signal, and then we recompressed the DSSS signal after NBI cancelation and realized the DSSS signal demodulation in compressed domain with the OMP algorithm. Simulation results support our theoretical analysis results and reveal that the two proposed algorithms are both effective for NBI cancelation and significant interference cancelation performance are achieved.

A novel hybrid compound fault pattern identification method for gearbox based on NIC, MFDFA and WOASVM

Gearbox compound fault pattern recognition is challenging because of its complexity and non-stationarity of the vibration signal. In this study is proposed a novel hybrid method based on narrow band interference canceller (NIC), multifractal detrended fluctuation analysis (MFDFA) and support vector machine optimized by whale optimization algorithm (WOASVM) for compound fault pattern recognition of gearbox. Specifically, the raw signal is processed by NIC to filter the deterministic signal which interferes with the fault signal, and then the multifractal features are extracted from the residual signal via MFDFA. Finally, the compound fault pattern is identified via WOASVM. Compound fault experiments of a gearbox under fixed condition and variable condition were done to evaluate the performance of the proposed method. The results show that the proposed method can effectively identify the compound faults and it outperforms other methods mentioned in this paper.

Comparison of null-subcarriers reservation and adaptive notch filter for narrowband interference cancellation in intra-data center interconnect with DMT signal transmission.

In this paper, we experimentally compare the performance of two different narrowband interference suppression schemes in 120 Gb/s intensity modulation and direct detection (IM/DD) system with discrete multi-tone (DMT) signal transmission for intra-data center interconnect (Intra-DCI). Digital pre-equalization and DFT-spread techniques are applied for system bandwidth limitation induced signal distortion compensation and signal peak to average power ratio (PAPR) reduction, respectively. Null-subcarriers reservation (NSR) and adaptive notch filter (ANF) techniques are compared during the suppression of digital-to-analog convertor (DAC) clock leakage induced narrowband interference. 1.2 dB and 1.8 dB DMT receiver sensitivity improvements can be achieved at a bit-error rate of 3.8 × 10-3 in optical back-to-back (OBTB) transmission when optimized NSR and ANF schemes are applied for narrowband interference cancellation, respectively. After 2-km single mode fiber (SMF) transmission, the required received optical power (ROP) of DMT signal with optimized NSR and ANF for narrowband interference cancellation at BER of 3.8 × 10-3 are -6.5 dBm and -7.1 dBm, respectively. Obviously, ANF outperforms NSR scheme in narrowband interference cancellation for DMT system.

Windowed overlapped frequency domain block filtering approach for direct sequence signal acquisition

This study applies a windowed frequency domain overlapped block filtering approach to acquire direct sequence signals. As a novel viewpoint, the windows not only allow pulse shaping without front-end pulse-shaping filter, but also increase the performance of the spectrum sensing unit, which can efficiently be implemented into this frequency domain receiver and may further be used for spectrum sensing in cognitive radios or narrowband interference cancellation in military radios. The proposed receiver is applicable for the initial time synchronization of different signals containing a preamble. These signals include single carrier, constant envelope single carrier, multicarrier, and even generalized multicarrier signals, making the proposed receiver structure a universal unit. Furthermore, the receiver can be used to perform filtering with long codes and compute the sliding correlation of an unknown periodic preamble. The receiver can further be modified to handle large Doppler shifts. We will also demonstrate herein the computational complexity and analysis of the acquisition performance in Rayleigh and Rician fading channels.

Two-Dimensional Structured-Compressed-Sensing-Based NBI Cancelation Exploiting Spatial and Temporal Correlations in MIMO Systems

Narrowband interference (NBI) caused by narrowband licensed or unlicensed services is a major concern that constrains the performance of multiple-input multiple-output (MIMO) systems. In this paper, the new and powerful signal processing theory of structured compressed sensing (SCS) is introduced to solve this problem. Exploiting the 2-D spatial and temporal correlations of NBI in MIMO systems, a novel NBI recovery method, i.e., the spatial multiple differential measuring method, is proposed in the framework of 2-D SCS. At each receive antenna, a differential measurement vector is acquired from the repeated training sequences in the IEEE 802.11 series preamble. Then, multiple measurement vectors from all receive antennas are utilized to recover and cancel NBI using the proposed SCS greedy algorithm of structured sparsity adaptive matching pursuit. Simulation results indicate that the proposed scheme outperforms the conventional schemes over the wireless MIMO channel.

Multiple Narrowband Interference Cancellation in High Data Rate UWB Body Area Networks using Hybrid Hermite Pulses

Body area networks (BAN) are being developed to serve the mankind, for detection of diseases and tracking of patients. And ultra wideband (UWB) has become the most preferred candidate for the physical layer of BAN. However, UWB BAN will suffer from the interferences from existing wireless networks. Though a number of mitigation techniques have been developed for UWB they will not be feasible for BAN because of their complexity and resulting power consumption. In this paper we propose hybrid Hermite pulse for cancelling multiple narrowband interferences. The technique is specially developed for UWB based BANs and has lower complexity compared to existing techniques. The proposed technique has been compared with its Gaussian counterpart and the performances have been studied through Monte-Carlo simulations in the BAN CM3 channel model. Further, ECG signal has been transmitted to validate the performance of the proposed technique.

Narrowband Interference Cancelation Based on Priori Aided Compressive Sensing for DTMB Systems

In this paper, a novel narrowband interference (NBI) cancelation scheme based on priori aided compressive sensing (CS) for digital terrestrial multimedia broadcasting systems is proposed. The repeated training sequences in the transmitted symbols are exploited by differential measuring to acquire the CS measuring vector of the NBI, and for joint acquisition of the NBI support priori. Using the proposed priori aided sparsity adaptive matching pursuit algorithm, the sparse high-dimensional NBI can be accurately reconstructed from the measuring vector of much smaller size obtained through the proposed CS-based differential measuring method. It is verified by theoretical analysis and simulations that the proposed method outperforms conventional anti-NBI methods under multipath broadcasting channels.

Enhanced bearing fault detection and degradation analysis based on narrowband interference cancellation

In the condition based maintenance work of rotating machineries, bearings’ fault diagnosis and prognosis are an important content. Their faults can lead to many disasters. So, to detect the bearing faults earlier can benefit the remaining useful life (RUL) prediction and maintenance actions. In order to achieve this goal, narrowband interference cancellation (NIC) is used to extract the periodic impulsive signals which are indicative of a bearing fault. This method filters the narrowband signals not associated with the impulsive signal produced by bearing faults out. Therefore, the signal-to-noise will be improved and lead to the easier fault detection. However, only easier fault detection is not enough for RUL prediction. The features extracted from the vibration signals should reflect the bearings’ degradation well. This needs the features have good degradation trend (increase or decrease with time). In order to demonstrate the effectiveness of the proposed method, one implemented bearing fault test and one run-to-failure test are used to do the analysis. The results shows that bearing faults detection can be enhanced and root mean square (RMS) extracted from the NIC signal can track the bearing degradation well than the RMS extracted from the original vibration signal.

Perfect symbol recovery and NBI suppression in MIMO‐OFDM systems

It is shown that by exploiting the degrees of freedom arising from the use of multiple antennas and/or insertion of virtual carriers in multiple-input multiple-output (MIMO) orthogonal frequency-division multiplexing (OFDM) systems, perfect symbol recovery and complete narrowband interference (NBI) cancellation can be achieved in the absence of noise by means of constrained minimum mean-output-energy linear filtering. Moreover, a nonlinear iterative scheme is proposed to improve NBI rejection in realistic operative conditions.

Filter Bank Based Notch Filter for Interference Cancellation in UWB Systems

The primary concern of any communication engineer is the bandwidth of the transmitted or received signal and the noise encountered during the transmission reception process. We analyze the effects of narrowband interference in Multicarrier UWB systems such as short distance IEEE 802.11a system. It is known that the process of narrowband interference cancellation is quite complex especially for ultra-wideband systems due to their power spectral density as low as -41dBm/MHz recommendations by the FCC. We review the model for narrow band interference and use the statistical property of correlation to determine the interference power spectral density. We review the sub band processing of UWB signals and apply notch filtering after measuring the threshold to eliminate the interference. We propose a novel mechanism for generation of the required notch filter using the sub band signals generated after the sub band decomposition of the UWB signal using filter banks. The proposed mechanism may be applied in conjunction with the other filter bank based multicarrier systems that have the advantage of better side-band attenuation of signals than commonly used OFDM system.

Multichannel self-optimizing narrowband interference canceller

The problem of cancellation of a nonstationary sinusoidal interference, acting at the output of an unknown multivariable linear stable plant, is considered. No reference signal is assumed to be available. The proposed feedback controller is a nontrivial extension of the SONIC (self-optimizing narrowband interference canceller) algorithm, developed earlier for single-input, single-output plants. The algorithm consists of two loops: the inner, control loop, which predicts and cancels disturbance, and the outer, self-optimization loop, which automatically adjusts the gain matrix so as to optimize the overall system performance. The proposed scheme is capable of adapting to slow changes in disturbance characteristics, measurement noise characteristics, and plant characteristics. It is shown that in the important benchmark case – for disturbances with random-walk-type amplitude changes – the designed closed-loop control system converges locally in mean to the optimal one. The algorithm, derived and analyzed assuming a single-tone, complex-valued disturbance with known frequency, can be extended to cope with a range of realistic applications, such as real-valued disturbances, multitone signals, and unknown frequency.

Efficient narrowband interference cancellation in ultra‐wide‐band rake receivers

In this study, different pulse modulation parameters, such as symbol error rate (SER), power loss and bandwidth were investigated to highlight the most suitable parameter for narrowband interference cancellation in ultra-wide-band (UWB) Rake receivers. Thus, the performance of transmitter pulse was evaluated at the UWB Rake receiver. Finally, comparison of various filter bank receivers in terms of number of filters and SER was achieved by using a new accurate indoor UWB IEEE model channel with different propagation scenarios.

Self-Optimizing Adaptive Vibration Controller

This paper presents a new approach to rejection of sinusoidal disturbances acting at the output of a discrete-time linear stable plant with unknown dynamics. It is assumed that the frequency of the sinusoidal disturbance is known, and that the output signal is contaminated with wideband measurement noise. The proposed controller, called SONIC (self-optimizing narrowband interference canceller), combines the coefficient fixing technique, used to robustify self-tuning minimum-variance regulators, with automatic adaptation gain tuning. Both theoretical analysis and computer simulations confirm that, under Gaussian assumptions, the closed-loop system converges (locally) in mean to the optimal solution.

Abstract: P934 DEVELOPING A MATHEMATICAL MODEL TO DETERMINE THE RATES OF LIPOPROTEIN METABOLIC PROCESSES FROM A SINGLE PLASMA SAMPLE

This paper presents set-membership estimation methods for narrowband interference cancellation (NBIC) in differential chaotic shift keying (DCSK) communication. Based on the boundedness of the chaotic carrier, two optimal bounding ellipsoid (OBE) algorithms are formulated, one with known and one with unknown interference parameters. Compared with the Kalman filter and recursive least-squares (RLS) algorithms, the proposed NBIC methods are computationally efficient due to the discerning update features that can estimate interfering signals with only a fraction of the observations. Simulation results illustrate that the proposed NBIC methods can suppress autoregressive (AR) or sinusoidal interference effectively.

New adaptive complex IIR filters and their application in OFDM systems

In this article, very low sensitivity variable complex filter (VCF) sections are developed. They have two important advantages: extremely low passband sensitivity and independent tuning of the bandwidth and the central frequency over a wide frequency range. The first advantage provides resistance to quantization effects, while the second one gives a better digital signal processing quality and extends the area of possible applications of the developed filters. Based on the proposed VCF sections an adaptive complex system is designed which demonstrates very fast convergence and low computational complexity. This system is applied for narrowband interference cancellation in multiband orthogonal frequency division multiplexing receivers and wideband noise cancellation in OFDM receivers. It is experimentally verified that a better signal-to-noise ratio and signal-to-interference ratio can be achieved using the proposed adaptive complex filtering scheme.

Narrowband interference cancellation based on set-membership estimation in DCSK communication system

This paper presents set-membership estimation methods for narrowband interference cancellation (NBIC) in differential chaotic shift keying (DCSK) communication. Based on the boundedness of the chaotic carrier, two optimal bounding ellipsoid (OBE) algorithms are formulated, one with known and one with unknown interference parameters. Compared with the Kalman filter and recursive least-squares (RLS) algorithms, the proposed NBIC methods are computationally efficient due to the discerning update features that can estimate interfering signals with only a fraction of the observations. Simulation results illustrate that the proposed NBIC methods can suppress autoregressive (AR) or sinusoidal interference effectively.

Successive NBI Cancellation Using Soft Decisions for OFDM Systems

Recently, we proposed a successive narrowband interference (NBI) cancellation method for orthogonal frequency-division multiplexing (OFDM) systems, which empowers the conventional one-tap frequency-domain equalizer to gain in robustness against NBI. In this letter, we generalize such an approach by using soft (instead of hard) feedback from the decoding unit, when the digitally-modulated NBI is (possibly) improper. It is shown that, with respect to our previous work, the devised equalizers allow one to achieve a significant performance gain, with a moderate increase in computational complexity.

Adaptive Blind Narrowband Interference Cancellation for Multi-User Detection

When overlaying spread spectrum (SS) transmission over a narrowband system, the performance of the spread spectrum system will be significantly degraded due to the interference from the narrowband signal. This paper proposes two computationally attractive and efficient adaptive techniques for narrowband interference (NBI) suppression in DS-CDMA system: adaptive linear predictor algorithm and adaptive NBI re-estimation algorithm. Unlike existing techniques in literature which use either estimator/subtracter approach or code-aided approach, the proposed methods combine these two approaches together and show that a much better performance can be achieved. In addition, the proposed algorithms are blind and do not require any training symbols and interference characteristics. The proposed methods not only provide faster convergence speed than the pure code-aided approach (without using a predictor and subtractor), but also give better BER performance

Successive narrowband interference cancellation for OFDM systems

We consider the problem of mitigating narrowband interference (NBI) in conventional orthogonal frequency-division multiplexing (OFDM) systems, wherein the presence of the NBI dramatically degrades the performances of both the linear zero-forcing and minimum mean-square error equalizers. A new receiver based on successive NBI cancellation is synthesized, which is capable of assuring good NBI rejection, without requiring insertion of additional redundancy in the OFDM signal