BROADBAND INTERFERENCE EXCISION IN SPREAD SPECTRUM COMMUNICATION SYSTEMS BASED ON SHORT-TIME FOURIER TRANSFORMATION

An interference excision algorithm in direct-sequence spread spectrum (DS-SS) communication systems is introduced. The proposed excision algorithm is developed for linear frequency modu- lated (LFM) signals that have broadband frequency characteristics. It is based on the time-frequency analysis of received signals employing short-time Fourier transformation (STFT). To analyze the interfer- ence, STFT of the received signal block is evaluated and thresholded. The interference detection is followed by an inverse-STFT computation to estimate the high-power jamming signal. The estimated jammer is then mitigated before demodulation. Simulations present adequate interference estimation results with mean estimation errors less than 0.01%. Various scenarios with different jammer-to-signal ratios (JSRs) and signal-to-noise ratios (SNRs) vs. bit error rates (BERs) are pre- sented for single and multi-component LFM signals. Interference exci- sion algorithms improve the system performance more than an order of magnitude.

[1]  Nikolaos K. Uzunoglu,et al.  IMPROVEMENT OF TRANSMISSION PROPERTIES OF MULTIMODE FIBERS USING SPREAD SPECTRUM TECHNIQUE AND A RAKE RECEIVER APPROACH , 2007 .

[2]  Renbiao Wu,et al.  Survey on Interference Mitigation via Adaptive Array Processing in GPS , 2006 .

[3]  Alan R. Lindsey,et al.  Broadband interference excision for software-radio spread-spectrum communications using time-frequency distribution synthesis , 1999, IEEE J. Sel. Areas Commun..

[5]  Dongning Li,et al.  Narrow-band interference suppression in spread spectrum communication systems , 1991, Signal Process..

[6]  Moeness G. Amin,et al.  Short-time Fourier transform receiver for nonstationary interference excision in direct sequence spread spectrum communications , 2001, IEEE Trans. Signal Process..

[7]  S. Ponnekanti,et al.  Non-Linear Interference Cancellation Techniques for Electromagnetically Dense Propagation Environments , 1998 .

[8]  Leonard E. Miller,et al.  NASA systems engineering handbook , 1995 .

[9]  J.B. Allen,et al.  A unified approach to short-time Fourier analysis and synthesis , 1977, Proceedings of the IEEE.

[10]  Fathi E. Abd El-Samie,et al.  Frequency Domain Interference Cancellation for Single Carrier Cyclic Prefix CDMA System , 2008 .

[11]  Chenshu Wang,et al.  Performance analysis of instantaneous frequency-based interference excision techniques in spread spectrum communications , 1998, IEEE Trans. Signal Process..

[12]  Albert Thomas.  INTERFERENCE SUPRESSION OF THE LINEAR ANTENNA ARRAYS CONTROLLED BY PHASE WITH USE OF SQP ALGORITHM , 2006 .

[13]  Moeness G. Amin,et al.  Interference mitigation in spread spectrum communication systems using time-frequency distributions , 1997, IEEE Trans. Signal Process..

[14]  Orhan Arikan,et al.  Short-time Fourier transform: two fundamental properties and an optimal implementation , 2003, IEEE Trans. Signal Process..

[15]  A Simulation Tool for Space-time Adaptive Processing in GPS , 2006 .

[16]  S. Sali,et al.  Non-Linear Interference Cancellation Techniques for Electromagnetically Dense Propagation Environments - Abstract , 1998 .

[17]  F. Hlawatsch,et al.  Linear and quadratic time-frequency signal representations , 1992, IEEE Signal Processing Magazine.

[18]  Chong Meng Samson See,et al.  Multiple UWB Emitters DOA Estimation Employing Time Hopping Spread Spectrum , 2008 .

[19]  Nasser Kehtarnavaz,et al.  An efficient recursive algorithm for time-varying Fourier transform , 1993, IEEE Trans. Signal Process..

[20]  Sultan Aldirmaz,et al.  Performance Analysis Of An STFT-Based Broadband Interference Excision Algorithm In DS-SS Systems , 2007, 2007 IEEE 15th Signal Processing and Communications Applications.

[21]  Ajay Chakraborty,et al.  FREQUENCY DOMAIN NLMS ALGORITHM FOR ENHANCED JAM RESISTANT GPS RECEIVER , 2008 .

[22]  W. Xue,et al.  MULTIPLE TARGETS DETECTION METHOD BASED ON BINARY HOUGH TRANSFORM AND ADAPTIVE TIME-FREQUENCY FILTERING , 2007 .