What is direct sequence spread spectrum concept?

What is direct sequence spread spectrum concept?

Direct-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.

What do you mean by spread spectrum explain DSSS & FHSS in detail?

It is an important encoding method for wireless communications to spread data over wide bandwidth and makes jamming and interception harder. Frequency Hoping: Signal broadcast over seemingly random series of frequencies.

Why is Direct Sequence Spread Spectrum?

Direct sequence spread spectrum (DSSS) is a transmission technology used in local area wireless network transmissions. In this technology, a data signal at the sending station is combined with a high data rate bit sequence, which divides user data based on a spreading ratio.

How is DSSS signal generated?

For DSSS transmissions, the data signal is multiplied with a pseudorandom spreading sequence that has a much higher bit rate than the original data rate. The resulting transmitted signal resembles bandlimited white noise, like an audio recording of “static”.

What are the characteristics of DSSS?

Features. DSSS phase-shifts a sine wave pseudorandomly with a continuous string of chips, each of which has a much shorter duration than an information bit. That is, each information bit is modulated by a sequence of much faster chips. Therefore, the chip rate is much higher than the information bit rate.

What is the spreading factor in DSSS?

One of the most essential attributes of DSSS coding is the spreading factor, which is defined as the quotient of the chip rate and the bit rate. As suggested by the above characteristics, DSSS does not affect the transmission time for the same transmitted packet.

Why is DSSS the most widely known and the most used of the spread spectrum types?

By transmitting over a wide frequency spectrum. Why is direct sequence spread spectrum (DSSS) the most widely known and the most used of the spread spectrum types? Its ease of implementation and high data rates.

What is spreading factor in DSSS?

What is the key advantage of DSSS?

Following are the benefits or advantages of DSSS: ➨It uses both time and frequency planes for transmission of information bits, effect of interference and fading can be minimized to great extent. ➨It can be employed in point to point applications at the rate of 11 Mbps.

How does DSSS achieve bandwidth spreading?

DSSS accomplishes its frequency spreading by transforming each bit into a distinct, longer sequence. For example, a single ‘1’ bit might become a particular 11-bit sequence (00010011100).

What are the applications of DSSS?

Direct sequence spread spectrum applications CDMA cellphone technology: The DSSS technique was used to provide a multiple access scheme that was used for 3G cellophane technology. Each mobile used a different access code or spreading code and this enabled multiple users to access the base station on the same frequency.