An FFT-Based Approach for Carrier Frequency Domain Acquisition in Spread Spectrum TT&C System

2011 ◽  
Vol 135-136 ◽  
pp. 211-216 ◽  
Author(s):  
Xing Cun Wu ◽  
Ping Gong ◽  
Hai Jun Song ◽  
Hui Zhi Zou
Keyword(s):  
Frequency Domain ◽  
Spread Spectrum ◽  
Carrier Frequency ◽  
Frequency Estimation ◽  
Doppler Frequency ◽  
Estimation Accuracy ◽  
Acquisition Time ◽  
Signal Acquisition ◽  
Parallel Acquisition ◽  
Doppler Compensation

Acquisition time of precision ranging code is long under the conditions of large Doppler shift, the carrier frequency domain FFT-based fast acquisition theory was analyzed, and the method of carrier Doppler compensation estimates to complete the PN code Doppler compensation was directly used in spread spectrum ranging signal acquisition. Comparing with the traditional parallel acquisition approach, the Doppler frequency estimation accuracy and acquisition speed is greatly improved, the acquisition time is shorter than long code segment with the traditional parallel acquisition method. Comparing with the method of short code supporting for long code, the channel energy is saved.

Research on Interpolation Algorithm for DSSS Signal Receiver

2013 ◽  
Vol 313-314 ◽  
pp. 1279-1284
Author(s):  
Zhi Qun Yang
Keyword(s):  
Spread Spectrum ◽  
Test Performance ◽  
Optimal Algorithm ◽  
Linear Interpolation ◽  
Direct Sequence Spread Spectrum ◽  
Signal Acquisition ◽  
Interpolation Algorithm ◽  
Effective Technique ◽  
Parallel Acquisition ◽  
Data Points

For Direct Sequence Spread Spectrum (DSSS) receiver, a parallel acquisition algorithm based on FFT-IFFT is proposed to improve speed of the DSSS signal acquisition. In order to ensure the FFT data points is equal to a power of 2(2N), Interpolation Algorithm is always used. In this paper, three interpolation algorithms are introduced in detail, and they are analyzed theoretically and compared by quantitative simulation, the resources occupied and test performance verification. We draw the conclusion that the linear interpolation is the optimal algorithm which offers the effective technique for the implementation of DSSS signal receiver.

A Novel Non-Data-Aided Frequency Estimation Algorithm for M-PSK Signals

2013 ◽  
Vol 756-759 ◽  
pp. 3109-3113
Author(s):  
Qing Hua Tian ◽  
Xin Man ◽  
Sheng Zeng
Keyword(s):  
Computational Complexity ◽  
Carrier Frequency ◽  
Frequency Estimation ◽  
Estimation Algorithm ◽  
New Method ◽  
Estimation Accuracy ◽  
Step Factor ◽  
Carrier Frequency Estimation ◽  
Estimation Range

This paper deals with the problem of carrier frequency estimation for MPSK symbols. We present a novel non-data-aided method by introducing a step factor into an earlier estimation algorithm to reduce the computational complexity with little loss of the estimation accuracy. We also make some comparisons with earlier algorithms. From the results of simulations, we make the conclusion that the new method can separate the estimation range and the estimation accuracy, and avoid the weakness of reaching large estimation range at the expense of estimation accuracy.

A Fast Acquisition Scheme for Coherent DDS/FFH System

2013 ◽  
Vol 427-429 ◽  
pp. 734-737
Author(s):  
Ce Lun Liu ◽  
Long Bo Han ◽  
Xu Su ◽  
Xiao Jie Wen
Keyword(s):  
Spread Spectrum ◽  
Matched Filter ◽  
Doppler Frequency ◽  
Signal Acquisition ◽  
Direct Sequence ◽  
System Realization ◽  
Acquisition Scheme ◽  
Large Spread ◽  
Realization Complexity ◽  
Fast Frequency Hopping

For a coherent DDS/FFH system (deeply direct sequence and coherent fast frequency hopping hybrid spread spectrum system), signal has a very large spread spectrum ratio. Signal acquisition process becomes very complex and difficult due to interference and doppler frequency shift in a strong interfering and high dynamical environment. FFT corelation sequence points are very large if traditional frequency-based FFT acquisition scheme is used, FFH requires FFT operation should be completed in a much shorter time (within one hopping duration time), which makes system realization become very complex or even impossible. A partial matched filter combining FFT, coherent accumulation combining incoherent accumulation acquisition scheme is investigated, system realization complexity is reduced.

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