Broadband Interference Excision in Spread Spectrum Communication Systems Based on Short-time Fourier Transformation

نویسندگان

  • S. Aldırmaz
  • L. Durak
چکیده

An interference excision algorithm in direct-sequence spread spectrum (DS-SS) communication systems is introduced. The proposed excision algorithm is developed for linear frequency modulated (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 interference, 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 presented for single and multi-component LFM signals. Interference excision algorithms improve the system performance more than an order of magnitude.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Narrow-Band Interference Suppression in CDMA Spread-Spectrum Communication Systems Based on Sub-Optimum Unitary Transforms

In this paper, we present several unitary transform-domain filtering techniques based on KarhaunenLoeve Transform (KLT) for narrow-band interference rejection in CDMA communication systems. The reason for selecting the KLT is that it is an optimum unitary transform in the sense of packing the energy of the narrow-band interference. As a result after applying this transform, a small portion of t...

متن کامل

Unmasking Optical Chaotic Cryptosystems Based on Delayed Optoelectronic Feedback

Chaotic signals typically have broadband spectrum. This property is desirable for applications that require robustness against interference, jamming and low detection probability. Those issues have been addressed by traditional communication systems by using spread spectrum and frequency hopping modulations. In chaos-based communications the broadband chaotic signal is generated at the physical...

متن کامل

An Analysis of a Real-time Transform Domain Ltering Digital Communication System: Part I: Narrowband Interference Rejection

A comparison of weighted and non-weighted transform domain processing systems for narrowband interference excision. Adaptive narrowband interference rejection in a ds spread spectrum intercept receiver using transform domain signal processing techniques. IEEE Transactions on Communications , 37, 1989. 4] John Guilford and P. Das. The use of the adaptive lattice lter for narrowband jammer reject...

متن کامل

Spread spectrum interference suppression using adaptive time-frequency tilings

Interference suppression in spread spectrum communication systems is often essential for achieving maximum system performance. Existing interference suppression methods do not perform well for most types of nonstationary interference. We rst consider interference suppression schemes based on adaptive orthogonal time-frequency decompositions, such as wavelet packet and arbitrary dyadic time-freq...

متن کامل

Broadband nonstationary interference excision for spread spectrum communications using time-frequency synthesis

A new method is introduced for interference excision in spread spectrum communications. Time-frequency synthesis techniques are used to synthesize the nonstationary jammer from the timefrequency domain using least-squares methods. The synthesized jammer is then subtracted from the incoming data in the time domain, leading to increased signal to interference ratio at the input of the correlator....

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2008