What is the bandwidth of spread-spectrum signal?

Hear this out loudPauseHard to detect: Spread-spectrum signals are much wider than conventional narrowband transmission (of the order of 20 to 254 times the bandwidth of narrowband transmissions). Since the communication band is spread, it can be transmitted at a low power without being detrimentally by background noise.

Which spread-spectrum is bandwidth efficient?

Hear this out loudPauseFHSS and DSSS / CDMA Spread spectrum multiple access techniques uses signals which have a transmission bandwidth of a magnitude greater than the minimum required RF bandwidth. These are of two types.

Which information direct sequence spread spectrum is used to transmit?

Hear this out loudPauseIn telecommunications, direct-sequence spread spectrum (DSSS) is a spread-spectrum modulation technique primarily used to reduce overall signal interference. The direct-sequence modulation makes the transmitted signal wider in bandwidth than the information bandwidth.

What is the width of Direct Sequence Spread Spectrum?

Hear this out loudPauseDirect Sequence Spread Spectrum (DSSS) However, the same principles apply: The redundant bit pattern in the spreading sequence increases the signals resistance to interference and also distributes the power over a 22-MHz-wide channel that looks essentially like low-power, wideband noise.

What are the spread spectrum techniques?

Hear this out loudPauseThere are two main types of spread spectrum techniques that are employed. These are Direct Sequence Spread Spectrum (DSSS) and Frequency Hopping Spread Spectrum (FHSS).

Is LTE a spread spectrum?

Hear this out loudPauseLTE is a broadband wireless technology that uses wide channels to achieve high data rates and accommodate lots of users. The standard is set up to permit bandwidths of 1.4, 3, 5, 10, 15, and 20 MHz. The carrier selects the bandwidth depending on spectrum holdings as well as the type of service to be offered.

What is direct sequence spread spectrum concept?

Hear this out loudPauseDirect-Sequence Spread Spectrum: A transmission technology used in WLAN (wireless LAN) transmissions where a data signal at the sending station is combined with a higher data-rate bit sequence, or chipping code, that divides the user data according to a spreading ratio.

Which modulation is used in direct sequence spread spectrum?

Hear this out loudPauseMost common are BPSK and QPSK modulation. The baseband direct sequence spread spectrum system spreads the baseband digital signal using the wide-bandwidth spreading-code signal. The spreading is done to the baseband signal directly without any digital modulation.

What are the two types of spread spectrum techniques?

Hear this out loudPauseSpread Spectrum can be categorized into two types: Frequency Hopping Spread Spectrum (FHSS) Direct Sequence Spread Spectrum(DSSS)

Why spread spectrum is used?

Hear this out loudPauseSpread Spectrum refers to a system originally developed for military applications, to provide secure communications by spreading the signal over a large frequency band. Figure 1 represents a narrow band signal in the frequency domain. These narrowband signals are easily jammed by any other signal in the same band.

Is VoLTE analog or digital?

Hear this out loudPauseVoice over LTE (VoLTE) is a digital packet technology that uses 4G LTE networks to route voice traffic and transmit data. This voice service is the standard for high-speed wireless communications in devices such as smart phones, data terminals, IoT devices and wearables.

What is the spread spectrum technique?

Hear this out loudPauseIn telecommunication and radio communication, spread-spectrum techniques are methods by which a signal (e.g., an electrical, electromagnetic, or acoustic signal) generated with a particular bandwidth is deliberately spread in the frequency domain, resulting in a signal with a wider bandwidth.

How does the spread spectrum work with BPSK?

In summary, the use of a spreading code (with pseudo-random properties) in the transmitter produces a wideband transmitted signal that appears noiselike to a receiver that has no knowledge of the spreading code.

How does the direct sequence spread spectrum work?

In direct sequence spread spectrum (DSSS), the transmitter and receiver contain identical psuedo-random sequence generators producing a pseudo-noise (PN) signal. In the transmitter, the input data stream is XORed with the PN signal before transmission.

How is the bandwidth of the spread spectrum measured?

The bandwidth of the spread spectrum signal will be much wider than the original data stream. To quantify the increase in bandwidth, a term known as the spreading gain is used. If the bandwidth of the DSSS, direct sequence spread spectrum signal is W and the input data bit length or period 1/R then the DSSS spreading gain can be defined:

How does a DSSS spread spectrum signal work?

When transmitting a DSSS spread spectrum signal, the required data signal is multiplied with what is known as a spreading or chip code data stream. The resulting data stream has a higher data rate than the data itself.