Code Division Multiple Access (CDMA) technology is primarily used in:
- A.Mobile phone communication
- B.X-ray
- C.Artificial Intelligence
- D.Colour Xerox
Correct answer
Explanation
The correct answer is A, Mobile phone communication. CDMA is a channel access method that lets many mobile users share the same radio frequency band at the same time.
In CDMA each call is given a unique code and spread over the whole available bandwidth, a technique called spread spectrum. The receiver uses the same code to pick out its own signal from all the others, which treat it like background noise. This gives good call quality, better security and efficient use of the spectrum. CDMA was the basis of 2G and 3G networks such as cdmaOne and CDMA2000, and its wideband form, WCDMA, was used in 3G UMTS. Other access methods are FDMA (division by frequency) and TDMA (division by time slots).
B is wrong because X-ray imaging uses high-energy radiation, not a multiple access scheme. C is wrong because Artificial Intelligence concerns machines that learn and reason, not sharing a radio channel. D is wrong because colour photocopying is a printing and imaging process.
Exam tip: multiple access methods are FDMA by frequency, TDMA by time and CDMA by code; GSM uses TDMA.
Practice Questions
View allWhich one among the following is not a part of the SWAYAM programme?
- A.Video lectures
- B.Classroom lectures
- C.Online discussion forum for clearing doubts
- D.Specially prepared material that can be downloaded/printed
Show answer
SWAYAM is an online learning platform, so live classroom lectures are not one of its parts.
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- A.COMMAND.COM
- B.AUTOEXEC.BAT
- C.CONFIG.SYS
- D.AUTOSTART.BAT
Show answer
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- A.It is an international open standard
- B.It is dependent on a computer's hardware
- C.It is independent of a computer's operating system
- D.It defines document type
Show answer
SGML was designed to be independent of both hardware and software, so saying it depends on a computer's hardware is false.
Read the full explanation →Which one among the following tasks is NOT carried out by an operating system?
- A.To link a program with the subroutines it references
- B.To manage data transfer to and from peripherals
- C.To allocate memory for storing programs
- D.To provide a layered, user-friendly interface
Show answer
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Read the full explanation →Which one among the following protocols works at application layer in a TCP/IP protocol suite?
- A.IP
- B.TCP
- C.TELNET
- D.Go-back-N
Show answer
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Read the full explanation →