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What is CDMA and how it works?
Code-division multiple access (CDMA) is a channel access method used by various radio communication technologies. CDMA is an example of multiple access, where several transmitters can send information simultaneously over a single communication channel.
What is CDMA explain in detail?
CDMA (Code-Division Multiple Access) refers to any of several protocols used in second-generation (2G) and third-generation (3G) wireless communications. As the term implies, CDMA is a form of multiplexing, which allows numerous signals to occupy a single transmission channel, optimizing the use of available bandwidth.
How CDMA works in wireless LAN?
How CDMA works. CDMA uses the spread spectrum wireless networking technology—first developed for military communication systems in the 1940s because it spreads its transmission over a large bandwidth, making it difficult to jam. The code tag then identifies the conversation to the transmission station.
How does CDMA transmit data?
CDMA uses multi access which allows several transmitters to send information at the same time over a single channel and with this, optimizes bandwidth. CDMA uses a Direct Sequence Spread Spectrum (DSSS) property where the transmitter and the receiver must use the same spreading code to transmit data.
What are the applications of CDMA?
CDMA allows for greater development and use of broadband devices such as GPS units, PDA’s, wireless laptop modems, Internet capable cell phones, and other innovative devices.
What are the features of CDMA?
In CDMA, every channel uses the full available spectrum. Individual conversations are encoded with a pseudo-random digital sequence and then transmitted using a wide frequency range. CDMA consistently provides better capacity for voice and data communications, allowing more subscribers to connect at any given time.
Which code is used in CDMA?
IS-95 CDMA Standard uses three types of codes namely 1) Long code 2) Short code and 3) Walsh Hadamard codes.
What is advantage of using CDMA over TDMA?
CDMA technology claims that its bandwidth is thirteen times efficient than TDMA and forty times efficient than analog systems. CDMA also have better security and higher data and voice transmission quality because of the spread spectrum technology it uses, which has increased resistance to multipath distortion.
Why is CDMA used?
Code Division Multiple Access (CDMA) is a sort of multiplexing that facilitates various signals to occupy a single transmission channel. It optimizes the use of available bandwidth. The technology is commonly used in ultra-high-frequency (UHF) cellular telephone systems, bands ranging between the 800-MHz and 1.9-GHz.
What is CDMA and its types?
What are advantages of CDMA?
One of the main advantages of CDMA is that dropouts occur only when the phone is at least twice as far from the base station. Thus it is used in the rural areas where GSM cannot cover. Another advantage is its capacity; it has a very high spectral capacity that it can accommodate more users per MHz of bandwidth.
What are the key elements of CDMA technology?
Key elements of CDMA. CDMA is a form of spread spectrum transmission technology based around a scheme called direct sequence spread spectrum. Direct sequence spread spectrum, DSSS is a form of radio transmission used in a variety of radio transmissions.
Why do you need a spreading code for CDMA?
Spreading codes used: In order to achieve the increased bandwidth, the data is spread by use of a code which is independent of the data. Level of security: In order to receive the data, the receiver must have a knowledge of the spreading code, without this it is not possible to decipher the transmitted data, and this gives a measure of security.
What is the processing gain of a CDMA signal?
• Direct Sequence Spread Spectrum (DSSS) CDMA is the method used in IS-95 commercial systems. Consider a user with a 9600bps vocoder talking on a CDMA signal 1,228,800 Hz wide. The processing gain is 1,228,800/9600 = 128, which is 21 db.
What is code division multiple access ( CDMA ) technology?
CDMA – Technology. Code Division Multiple Access (CDMA) is a sort of multiplexing that facilitates various signals to occupy a single transmission channel. It optimizes the use of available bandwidth.