The separation of signals with temporal structure from mixed sources is a challenging problem in signal processing. For this problem, blind source extraction (BSE) is more suitable than blind source separation (BSS) because it has lower computation cost. Nowadays many BSE algorithms can be used to extract signals with temporal structure. However, some of them are not robust because they are too dependent on the estimation precision of time delay; some others need to choose parameters before extracting, which means that arbitrariness can't be avoided. In order to solve the above problems, we propose a robust source extraction algorithm whose performance doesn't rely on the choice of parameters. The algorithm is realized by maximizing the objective function that we develop based on the non-Gaussianity and the temporal structure of source signals. Furthermore, we analyze the stability of the algorithm. Simulation results show that the algorithm can extract the desired signal from large numbers of observed sensor signals and is very robust to error in the estimation of time delay.

In this paper, a new effective C/N0 theoretical model for global navigation satellite system (GNSS) receiver is proposed, in the presence of continuous wave interference (CWI). The proposed model is derived based on an interesting finding, correlator may output direct current (DC) in the presence of CWI. The DC introduced by CWI eventually leads to increase of carrier power estimation. It is totally different from current assumption that interference just causes noise power increase after correlation. The proposed model is verified by simulation.

This letter presents an improved peak cancellation (PC) scheme for peak-to-average power ratio (PAPR) reduction in orthogonal frequency division multiplexing (OFDM) systems. The main idea is based on a serial peak cancellation (SPC) mode for alleviating the peak regrowth of the conventional schemes. Based on the SPC mode, two particular algorithms are developed with different tradeoff between PAPR and computational complexity. Simulation shows that the proposed scheme has a better tradeoff among PAPR, complexity and signal distortion than the conventional schemes.

To reduce the common mode voltage (CMV), suppress the CMV spikes, and improve the steady-state performance, a simplified reactive torque model predictive control (RT-MPC) for induction motors (IMs) is proposed. The proposed prediction model can effectively reduce the complexity of the control algorithm with the direct torque control (DTC) based voltage vector (VV) preselection approach. In addition, the proposed CMV suppression strategy can restrict the CMV within ±Vdc/6, and does not require the exclusion of non-adjacent non-opposite VVs, thus resulting in the system showing good steady-state performance. The effectiveness of the proposed design has been tested and verified by the practical experiment. The proposed algorithm can reduce the execution time by an average of 26.33% compared to the major competitors.

In this letter, a low complexity transmitter is proposed for the downlinks of orthogonal frequency code division multiplexing (OFCDM) systems. The principle is based on a joint time-frequency spreading and inverse fast Fourier transform (TFS-IFFT), which combines the frequency spreading with partial stages of IFFT, so as to simplify the real-time processing. Compared with the conventional one, the proposed OFCDM transmitter is of lower real-time computational complexity, especially for those with large spreading factor or low modulation level. Furthermore, the proposed TFS-IFFT can also be applied to other frequency spreading systems, such as MC-CDMA, for complexity reduction.

This letter presents a low-profile printed monopole wideband antenna for mobile terminals. The proposed antenna is simply structured with an inverted-L strip, which occupies the small area of 3180.8 mm3 (0.023λL0.138λL0.006λL at lower frequency edge of 2.3 GHz) on a substrate which is perpendicular to the circuit board of the terminal. The height of the upright substrate is only 3 mm (3.8 mm including the circuit board). The proposed antenna achieves a 10-dB impedance bandwidth of 59.7% ranging from 2.16 GHz to 4 GHz, which can cover which can cover the 2.4 GHz WLAN (2.4-2.4835 GHz) and WiMAX (2.3-2.4/2.495-2.69/3.4-3.6 GHz) operational bands. It is suitable for application to a multiband mobile phone due to its relatively low profile.

Global navigation satellite system (GNSS) receivers equipped with the frequency domain interference suppression (FDIS) filter can operate in environments with harsh interference. The FDIS will not cause tracking error bias for an ideal analog receiver channel as its magnitude response and phase response are constant. However, the analog receiver channel distortion is induced by RF cables, amplifiers, and mixers. The distortion of the channel caused asymmetry correlation function. The correlation function is further deformed by the FDIS filter. More seriously, since the FDIS filter is adaptive, the bias will vary with the jamming pattern, especially when the frequency of interference is varying. For precision navigation applications, this bias must be mitigated. Fortunately, to prevent power loss, the analog receiver channel filter is a real function or the imaginary part is negligible. Therefore, the magnitude response and the phase response are even functions. Based on these channel features, a new FDIS filter based on mirror frequency amplitude compensation (MFAC) method is proposed in this paper. The amplitude of the symmetry position of the notch frequency is doubled in the MFAC method in order to mitigate the tracking bias. Simulation results show that the MFAC-based FDIS method is capable of reducing the bias error to less than 0.1ns, which is significant smaller than that achieved by the traditional FDIS method.