Doppler estimation for fast acquisition in spread spectrum communication systems

Grant, Peter; Spangenberg, S.M.; Scott, Iain; McLaughlin, Stephen; Povey, G.J.R.; Cruickshank, D.G.M.

doi:10.1109/isssta.1998.726206

Cited by 26 publications

(12 citation statements)

References 5 publications

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“…If the maximum peak of the frequency domain exceeds threshold value, the local code phase and the input signal are consistent. With the location of the maximum peak of the frequency domain, we can calculate the doppler frequency shift [3] .…”

Section: B the Segment Correlation Algorithmmentioning

confidence: 99%

Improved fast fourier transform processing on fast acquisition algorithms for GPS signals

Zhao¹,

Gao²,

Hao³

2009

2009 9th International Conference on Electronic Measurement &Amp; Instruments

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The fast acquisition algorithms for high dynamic GPS signals was analyzed, and the result indicated that the fast fourier transform FFT played an important role in both the segment correlation algorithm and the fast acquisition algorithm based on FFT. So improving the efficiency of FFT can be significantly better the performance of GPS receivers. Considering the pros and cons of the FFT processing algorithms, a combination algorithm was put forward, which was applied to the GPS C/A signals acquisition. Simulation experiments was implemented to test the combination algorithm, and the results verify that the algorithm could obviously reduce the calculating amount without any loss of accuracy.

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Section: B the Segment Correlation Algorithmmentioning

confidence: 99%

Improved fast fourier transform processing on fast acquisition algorithms for GPS signals

Zhao¹,

Gao²,

Hao³

2009

2009 9th International Conference on Electronic Measurement &Amp; Instruments

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“…This fact can be exploited to reduce the search range and thus reduce the computational complexity, by employing partial matched filters (PMFs) [2], [3]. In this approach we construct a new sequence r c (l) from the original sequence r(k):…”

Section: Partial Matched Filtersmentioning

confidence: 99%

“…Another possibility to perform the 2D search is by means of a fast Fourier transform (FFT) [1], [2]. Especially, when a large frequency range has to be covered, it seems to be a good approach, because it can easily be adjusted to the acquisition range (see [3]) and the complexity is smaller than in a parallel filter bank. In different fields there has been research about ways to reduce the computational complexity of FFTs, by reducing memory references or simplifying the multiplication operations [10], [11], [12].…”

Section: Introductionmentioning

confidence: 99%

Code Acquisition in Direct Sequence Spread Spectrum Communication Systems Using an Approximate Fast Fourier Transform

Periša

Lindner

2006

2006 IEEE Ninth International Symposium on Spread Spectrum Techniques and Applications

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Abstract-This paper deals with code acquisition in communication systems with large frequency offsets. In such a situation, the receiver has to perform a 2-dimensional search in a time-frequency plane to detect a known signal. In previous publications it has been proposed to use a fast Fourier transform (FFT) to implement the search in frequency direc-We would here like to examine the effect of using approximate FFTs. For this puropose, we restrict the angles of the complex multiplications that are used in the FFT to four or eight states. This helps to reduce the total number of real multiplications. Further, there is no need to store trigonometric values. The drawback is that the approximations lead to a degradation at the FFT output. We will show, however, that in a two-stage acquisition scheme, where the FFT is only used to obtain an estimate of the frequency offset, approximate FFTs achieve almost the same performance as a conventional FFT.

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“…Especially for DS-CDMA satellite communication systems, twodimensional (2-D) search algorithms [23]- [25] have been considered where the acquisition for the Doppler shift and PN code phase is jointly accomplished. Reference [26] proposed a simple and efficient compensation algorithm for residual frequency error after coarse acquisition via 2-D search process.…”

Section: Doppler Shift Compensationmentioning

confidence: 99%

Rain Attenuation and Doppler Shift Compensation for Satellite Communications

Kim¹,

Lim²,

Choi³

et al. 2002

ETRI J

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structure and the ability to effectively compensate for rain attenuation and the Doppler shift.The non-geostationary satellite channel for high speed communications cannot be considered an additive white Gaussian noise (AWGN) channel because of signal fading due to rain and the Doppler shift on the channel. For these reasons, we developed our own rain attenuation model with which we can synthesize the dynamic characteristics of rain attenuation. Carrier offset induced by the Doppler shift is also modeled by the orbit constellation parameters of a non-geostationary orbit satellite system.A simple and efficient estimation and prediction algorithm for channel conditions was required for allocating suitable transmission schemes at each sampling time. We developed various control algorithms and estimated their performance using the rain attenuation model. This paper proposes an efficient transmission system which can be adaptively applied in rain attenuation situations. Our system uses a block turbo code with an M-ary phase shift keying (PSK) strategy and for Doppler shift compensation, a 2-dimensional search algorithm which uses fast Fourier transform (FFT). Because of the successful development of code division multiple access (CDMA) technology for terrestrial mobile communications [3], application of CDMA to satellite communication is now being attempted. We developed a CDMA-based Doppler shift compensation technique to conform to this technological trend.In section II, we briefly present a simulation modeling technique for rain attenuation and the Doppler shift on the satellite communication channel. Section III describes the adaptive transmission scheme and the Doppler shift compensation method, and demonstrates simulation results using our own developed simulation software (S/W) packages. Section IV introduces a hardware (H/W) emulation board with an adaptive rain attenuation compensation algorithm. Finally, conclusions are drawn in section V. II. CHANNEL MODEL 1. Rain Attenuation ModelWe previously developed a rain attenuation model with which we can synthesize time-varying rain attenuation for any given time interval at Ku and Ka frequency bands [4]. This was necessary so that we could estimate the performance of the proposed adaptive compensation algorithm.Several papers have presented techniques on dynamic rain attenuation modeling [5]- [7]. Because Korea experiences heavy rain during a short period, it was difficult to synthesize rain attenuation. Therefore, we believed it necessary to develop a rain attenuation model which could synthesize typical Korean rain attenuation dynamics. The rain attenuation model we developed used measured attenuation data from the 12.25 GHz beacon signal of Koreasat 2 for two years; an example is shown in Fig. 1. Motivated by the fact that rain attenuation is a Markov process, a Markov chain [8] was used to model the rain attenuation process. We assumed that a rain event could be characterized by a 4-state Markov-chain. That is, a rain event consists of a beginning, a fading, ...

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Doppler estimation for fast acquisition in spread spectrum communication systems

Cited by 26 publications

References 5 publications

Improved fast fourier transform processing on fast acquisition algorithms for GPS signals

Improved fast fourier transform processing on fast acquisition algorithms for GPS signals

Code Acquisition in Direct Sequence Spread Spectrum Communication Systems Using an Approximate Fast Fourier Transform

Rain Attenuation and Doppler Shift Compensation for Satellite Communications

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