DSSS (Direct Sequence Spread Spectrum) is one of the main technique of spread spectrum system and is the most common version use for military communication. In this paper, I have designed and implemented RADAR (Radio Wave Detection and Ranging) transmitter and receiver using direct sequence spread spectrum for range estimation. Most challenging part in RADAR system is to be getting better accur...

Indoor localization of persons and objects poses a great engineering challenge. Previously developed localization systems demonstrate the use of wideband techniques in ultrasound ranging systems. Direct sequence and frequency hopping spread spectrum ultrasound signals have been proven to achieve a high level of accuracy. A novel ranging method using the frequency hopping spread spectrum with fi...

We compare single user digital multi-carrier spread spectrum (MC-SS) modulation with direct sequence (DS) SS (with a modified implementation) in the presence of narrowband interference (NBI) and multipath fading. We derive closed-form expressions for the symbol error probability for both the linear MMSE receiver as well as the conventional matched-filter receiver under different scenarios: addi...

Direct sequence spread Spectrum (DSSS), is also called as direct sequence code division multiplexing (DS-CDMA). In direct sequence spread spectrum, the stream of information to be transmitted is divided into small pieces, each of which is allocated across to a frequency channel across the spectrum. A data signal at the point of transmission is combined with a higher data-rate bit sequence (also...

In this lecture we consider direct-sequence spread-spectrum systems. Unlike frequency-hopping, a direct-sequence signal occupies the entire bandwidth continuously. The signal is obtained by starting with a narrowband signal and directly modulating a high bandwidth signal. As with frequency hopping direct-sequence has advantages when the channel contains a jamming like signal. The jamming could ...

The processing that is often employed in receivers for quaternay direct-sequence spread-spectrum communications operates separately on the inphase and quadrature components of the spread-spectrum signal. Recent results on quaternary complex sequences, which are also referred to as four-phase sequences, provide a strong motivation to emplo~ processing methods that permit the receiver to benefit ...

Recently, a digital communication receiver, called a third-generation receiver, has been developed. This receiver takes samples of the direct-sequence spread signal at a nonzero intermediate frequency (IF) instead of the zero IF (baseband), and quantizes the samples by employing a 1-b analog-to-digital (A/D) converter at the receiver front end. These 1-b samples are digitally processed for pseu...