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The nonlinear characteristics of RF power amplifiers is an important research direction. To address the problem of high sampling rate in the amplifier predistortion system, this paper proposed a new brodaband power amplifier predistortion model. Firstly, it used the modulation wideband converter ( MWC ) based on sinusoidal frequency modulation ( SFM ) signal to spare the signal in the feedback loop, and then used the variable step size generalized adaptive matching tracking( VS-GSA MP ) algorithm to reconstruct the signal. The experimental results show that normalized mean squared error ( NSME ) is about 2 - 3 dB better than memory polynomial( MP) model and the general memory polynomial( GMP) model. The adjacent channel power radio can be improved to 21 dB. Good linear performance can be achieved at a lower sampling rate. [ABSTRACT FROM AUTHOR]

In order to solve the influence of noise samples in the underground WLAN radio fingerprint database on the personnel positioning accuracy, this paper proposed a new autocorrelation filtering algorithm based on sampling interval τ. The research shows that although the received signal strength ( RSS) sequences collected by the same mobile terminal are different at the same reference point and different time, there are significant differences of RSS between noise samples and other samples. Using this feature, this filtering algorithm based on sampling interval τ was used the mean of the samples as the balance reference of the fluctuation difference between two samples, which enlarged the anomalous characteristics of the noise samples,so that the possible noise samples could be filtered more accurately. The radio fingerprint database which filtered out the noise samples could better represent the RSS distribution at each reference point. With 90% confidence probability, the experimental results show that the location errors of static and dynamic personnel positioning using radio fingerprint samples filtered by autocorrelation filtering algorithm are 3 m and 3. 5 m respectively, which are 1 m and 0.5 m less than those using original radio fingerprint samples. [ABSTRACT FROM AUTHOR]

Copyright of Telecommunication Engineering is the property of Telecommunication Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Telecommunication Engineering is the property of Telecommunication Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Telecommunication Engineering is the property of Telecommunication Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Systems Engineering & Electronics is the property of Journal of Systems Engineering & Electronics Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Telecommunication Engineering is the property of Telecommunication Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Telecommunication Engineering is the property of Telecommunication Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The received signal of multiple input multiple output-orthogonal frequency division multiplexing (MIMO-OFDM) wireless communication system forms a multi-factor array signal from the view of space, time and frequency dimension. The traditional vector or matrix algebraic methods cannot perform well when processing multi-factor signals and cannot make use of the relationship among factors. Tensor analysis has an advantage in processing multi-dimension array signal. Considering the MIMO wireless communication system with OFDM technique, this paper researches on the tensor modeling and decomposition methods and aims to increase the detection ability of wireless received signal by use of the uniqueness of tensor decomposition. The received tensor signal with unknown channel state information (CSI) in MIMO-OFDM system is modelled and detected blindly based on the CANDECOMP/PARAFAC (CP) decomposition method. Simulation results verify the feasibility of the modeling. When the number of receiving antennas is larger than that of the transmitting antennas and the multi-path signals are independent, the blind detection algorithm based on CP decomposition can obtain about 5 dB gain in terms of signal-to-noise ratio (SNR) for bit error rate(BER) 10-4 with the number of receiving antennas increasing. [ABSTRACT FROM AUTHOR]

It introduces a new type of double radio frequency low noise amplifier circuits with the function of switching between inner and outer antenna using GPS L1, L2 band & GLONASS G1, G2 band. The low noise amplifier circuit structure was improved, and the amount of restraint outside the band increased ob-viously, making it have beter ability to resist interference. The new type of circuits had the function of switching between inner and outer antenna to avoid the influence of the outer antenna port interface on the signals of the inner antenna. The simulation results show that this new type of double radio frequency low noise amplifier circuits have low noise figure, high gain flatness and the ability of out-of-band rejection. The circuit's stability is good. A circuit sample was made, and then the debugging and testing were car-ried out. The main technical parameters of the measured results are in agreement with the simulation ones. The new type of double radio frequency low noise amplifier circuits have good characteristics. The sample circuit structure is compact, and the occupancy of PCB board area is leeser, which is very suit-able for hand-held high precision positioning receivers. [ABSTRACT FROM AUTHOR]

High precise attitude can be determined using GNSS signal, but the performance of GNSS-based attitude determination algorithm is affected by different signal structures. To deal this problem, first, the relationship between performance of algorithm and accuracy of code and carrier phase is analyzed based on the mathematical model of GNSS-based single frequency single epoch attitude determination algorithm, and then the effects of signal structures on the tracking accuracy of code and carrier phase are studied, finally the key indicator is presented to evaluate the effect of signal structures on the performance of attitude determination algorithm. The simulation results demonstrate that the indicator can evaluate the performance of attitude determination algorithm under different signal structure effectively while the conclusion is important for GNSS signal design and signal selection of receivers. [ABSTRACT FROM AUTHOR]

The problem of suppressing the repeater spoofing interferences effectively has become a must for the design of military anti-jamming satellite navigation receivers. By analyzing the code phase characteristic of satellite signals and repeater spoofing interferences, this research proposes a method of FFT fast acquisition of long code based on delay-waiting strategy. The method distinguishes satellite signals from repeater spoofing interferences according to the code phase information of the correlation peak whose amplitude is above the threshold. Thus the acquisition performance in the scene of repeater spoofing interferences can meet the demand without degradation in normal conditions. The theory analysis and simulation results validate the effectiveness of proposed method. [ABSTRACT FROM AUTHOR]