What is Code Division Multiple Access CDMA and how it works?
What is Code Division Multiple Access CDMA and how it works?
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.
Is CDMA a spread spectrum?
To permit this without undue interference between the users, CDMA employs spread spectrum technology and a special coding scheme (where each transmitter is assigned a code). CDMA optimizes the use of available bandwidth as it transmits over the entire frequency range and does not limit the user’s frequency range.
What is CDMA spectrum?
Spread spectrum is a form of wireless communications in which the frequency of the transmitted signal is deliberately varied resulting higher bandwidth. …
Which technique is used in CDMA telephony to support multiple access?
The CDMA channel is nominally 1.23 MHz wide. CDMA networks use a scheme called soft handoff, which minimizes signal breakup as a handset passes from one cell to another. The combination of digital and spread spectrum modes supports several times as many signals per unit of bandwidth as analog modes.
Why is multiple access required?
Multiple access schemes are used whenever there is a need for a number of independent users to share a resource that may be scarce or expensive. Orthogonal multiple access schemes refer to techniques that allow two or more users to share radio frequency spectrum in a manner that avoids collision.
What is Walsh code in CDMA?
Walsh Code is a group of spreading codes having good autocorrelation properties and poor cross correlation properties. Walsh codes are the backbone of CDMA systems and are used to develop the individual channels in CDMA. Code `0′ is used as the pilot and code `32′ is used for synchronization.
How does code Division Multiple Access CDMA allow channel reuse?
The IS-95 CDMA and CDMA radio channels use coded channels that are uniquely assigned to each user. This allows many users to operate on the same frequency. This also allows frequencies to be reused in every cell site and sectors within a cell site.
How does Code Division Multiple Access CDMA allow channel reuse?
What do you mean by spread spectrum multiple access?
Spread spectrum multiple access (SSMA) uses signals which have a transmission bandwidth whose magnitude is greater than the minimum required RF bandwidth.
