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The Golay complementary sequences (GCSs) over 22μ-quadrature amplitude modulation (QAM) constellation are investigated (integer μ ≥ 2), based on the binary standard generalized Boolean functions (GBFs). We develop a sufficient condition so as to produce 22μ-QAM GCSs. Different from the known 22μ-QAM GCSs, the proposed ones are educed by binary signals instead of quaternary signals. Hence, the resultant...
This paper presents two new mathematical expressions of square quadrature amplitude modulation (QAM) constellation with order 4q (integer q ≥ 2). One of them consists of 2q independent quaternary variables. The other consists of 2(2q − 1) independent binary variables. The number of independent variables of both expressions is twice as many as the one in the previously known expressions. One of applications...
This paper focuses on investigation of periodic complementary sequence sets over quadrature amplitude modulation (QAM) constellation. We propose a method converting existing binary mutually uncorrelated complementary sequence sets (MUCSSs) into required sequence sets, and discuss family size of the resultant sequence sets. More clearly, the number of new sequence sets is an exponent of period of sub-sequences...
In a long running system, software tends to encounter performance degradation and increasing failure rate during execution, which is called software aging. The bugs contributing to the phenomenon of software aging are defined as Aging Related Bugs (ARBs). Lots of manpower and economic costs will be saved if ARBs can be found in the testing phase. However, due to the low presence probability and reproducing...
Debugging multi-task real-time VxWorks applications is tedious and time-consuming for developers. The non-determinism within the application execution makes the developers hard to reproduce a failure.1As a result, the developers cannot perform cyclic debugging easily on these real-time applications. Replay debugging techniques can help developers to replay the failure scenario with determinism. In...
As users are increasingly concerned about energy efficiency, they are also increasingly intolerant of performance anomalies of programs that may cause significant energy waste. Bug localization is a bottleneck in the development of multithreaded programs. Although both static and dynamic performance bug localization techniques have been proposed, they cannot handle performance anomalies with unforeseen...
In communications, 8-QAM+ signals have a large number of their own advantages in comparison with other signals. This paper summarizes the existing methods producing 8-QAM+ sequences, and the relevant results. The constructions of three families of 8-QAM+ sequences: perfect 8-QAM+ sequences, perfect 8-QAM+ arrays, and 8-QAM+ complementary sequences are in detail stated, and their flaws are revealed...
This paper focuses on the construction of 16-QAM Golay complementary sequence pairs (CSPs) of length N = 2n. Based on the standard binary Golay-Davis-Jedwab (GDJ) CSPs, we present a method so as to convert the aforementioned GDJ sequence pairs into the required sequence pairs. The resultant sequence pairs have the upper bound 2N of peak envelope power (PEP), and their family size arrives at (20n-16)(n!/2)2...
Dynamic fault localization is a representative concept and product proposed by academia to alleviate software engineering pains, but it is rarely heard adopted or used in realistic development. Realizing the difficulties in transferring the approaches of dynamic fault localization to practical tools, this paper gives our work FLAVS, whose add-in implementation organically and seamlessly integrates...
Performance is an important indicator of firewalls effectiveness, which represents capability of firewalls handling network requests. ModSecurity and iptables, two representative firewalls of packet filtering and application firewall, are studied experimentally in this paper. Firstly, we develop the experiments to test the capacity of these two kinds of firewalls. Secondly, we locate the bottlenecks...
The given examples show that the standard 16-QAM Golay-Davis-Jedwab (GDJ) complementary sequences (CSs) cannot be yielded whenever the non-standard generalized Boolean functions (GBFs) are fed to Chong, et al's construction. Due to the fact that there exist a large number of the non-standard GBFs available, this paper focuses on the conversion from a non-standard GBF to 16-QAM CSs. By improving Chong,...
In communications, radar, sonar, and so forth, perfect arrays play fairly important roles. In this paper, we will investigate the construction methods of such arrays over the 8-QAM+ constellation. More clearly, for a given existing perfect ternary array (PTA), we will present two methods to convert it into an 8-QAM+ perfect array, depending on the existence of odd number in its size or not, respectively...
As a key point of orthogonal frequency division multiplexing (OFDM) technology, carrier frequency offset (CFO) has a significant effect on OFDM system performance. This paper proposes a CFO estimation method by using complementary sequence (CS) as training sequence. The proposed CS-based method can operate integer CFO and fractional CFO estimations on the basis of the same training sequence. The fractional...
Based on the cascade of cyclic shift versions of complementary pairs, a new set of mutually orthogonal sequence pairs with the center element of each sequence equal to zero is constructed. Compared with traditional complementary sequences, the constructed mutually orthogonal sequence pairs will be more suitable for orthogonal frequency division multiplexing (OFDM) systems when the zero element in...
Two novel recursion constructions of mutually orthogonal complementary pairs (MOCPs) are respectively presented on the basis of concatenation and interleaving operations. For the proposed set consisting of MOCPs, the zero-shift cross-correlation function between any two complementary pairs is equal to zero, that is, all of complementary pairs in MOCPs set are orthogonal to each other, as suggested...
Cascaded integrator-comb (CIC) filter plays a vital role in sampling rate conversion of digital intermediate frequency (IF) architecture. Due to no multipliers and limited storage, CIC filter can economically complete interpolation and decimation, which has a quite important significance especially for wideband communication systems with high data rate. This paper presents an efficient digital IF...
The last decade has witnessed an increase in interest in the application of airborne LiDAR data and high spatial resolution satellite imagery for forest structure modelling, tree species identification and classification. The integration of LiDAR data and WorldView-2 satellite imagery produced different combinations of input data layers for image segmentations and a large number of variables derived...
Image denoising has been fanatically researched for a very long time in that it is a commonplace yet important subject. The task to testify the performance of different image de-noising methods always resorts to PSNR in the past, until the emergence of SSIM, a landmark image quality assessment (IQA) metric. Since then, a vast majority of IQA methods were introduced in terms of various kinds of models...
Sequences with impulse-like autocorrelation are widely applied to synchronization, channel estimation, and so forth. Based on ternary complementary sequence pairs and interleaved technique, this paper presents a construction method for producing a family of imaginary sequences with impulse like real-part of autocorrelation over 8-QAM constellation. And the resultant sequences have arbitrary even period...
In software debugging, statistical fault localization techniques contrast dynamic spectra of program elements to estimate the location of faults in faulty programs. Coincidental correctness may have a negative impact on these techniques because faults can also be triggered in an observed non-failed run and thus disturbs the assessment of fault locations. However, eliminating the confounding relies...
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