Why near-far effect is there in CDMA and not in gsm?

1. Why near far problem occurs in CDMA?
2. Why near far problem occurs in CDMA based wireless communication and how it can be dealt?
3. What is near far problem in CDMA How do you overcome it ques10?
4. Why CDMA Cannot be used for higher bit rates?
5. How does near-far effect influence CDMA system?
6. What is a good code for CDMA?
7. Why is power control important in CDMA?
8. How do you prevent adjacent channel interference?
9. Why the shape of the cell is not circle?
10. What is CDMA full form?
11. What is CDMA cellular technology?
12. Why spread spectrum technique is inefficient for single user?
13. Why CDMA is not used in satellite communication?
14. Why CDMA is more efficient and secure?

Why near far problem occurs in CDMA?

CDMA near far problem basics

The CDMA near far problem arises because handsets may be anywhere within the particular cell boundaries. Some handsets will be close to the base station, whereas others will be much further away.

Why near far problem occurs in CDMA based wireless communication and how it can be dealt?

Solutions. In CDMA systems and similar cellular phone-like networks, the problem is commonly solved by dynamic output power adjustment of the transmitters. That is, the closer transmitters use less power so that the SNR for all transmitters at the receiver is roughly the same.

What is near far problem in CDMA How do you overcome it ques10?

To combat the near-far problem, power control is used in most CDMA implementations. Power control is provided by each base station in a cellular system and assures that each mobile in base station coverage area provides the same signal level to the base station.

Why CDMA Cannot be used for higher bit rates?

CDMA has a soft capacity. The greater the number of codes, the more number of users. However, many codes are used S/I drops and the BER (Bit Error Rate) will increase for all users. CDMA requires a tight power control as it suffers from near-far effect.

How does near-far effect influence CDMA system?

How Near-Far Problem Affects Communication? ... Desired signal power will be much higher than the interfered signal power and hence SN ratio of user A will be smaller and communication quality of user A will be severely degraded.

What is a good code for CDMA?

Ideal codes for CDMA should have delta function as their autocorrelation functions, and 0 for cross-correlation functions, i.e., autocorrelation function \rho(\tau) = \delta(\tau). cross-correlation functions \rho_i,j(\tau)=0, for all i \neq j, for all \tau.

Why is power control important in CDMA?

In CDMA, since all the mobiles transmit at the same frequency, the internal interference of the network plays a critical role in determining network capacity. Further, each mobile transmitter power must be controlled to limit the interference. Power control is essentially needed to solve the near-far problem.

How do you prevent adjacent channel interference?

The ACI can be reduced by: (1) using modulation schemes which have low out-of-band radiation; (2) carefully designing the bandpass filter at the receiver front end; and (c) assigning adjacent channels to different cells in order to keep the frequency separation between each channel in a given cell as large as possible.

Why the shape of the cell is not circle?

Why the shape of cell is not circle? Explanation: Circle is the first natural choice to represent the coverage area of a base station. But while adopting this shape, adjacent cells cannot be overlaid upon a map without leaving gaps or creating overlapping regions.

What is CDMA full form?

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 cellular technology?

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.

Why spread spectrum technique is inefficient for single user?

17. Why spread spectrum technique is inefficient for a single user? Explanation: Spread spectrum systems are bandwidth inefficient for single users. But in spread spectrum systems, many users can simultaneously use the same bandwidth without significantly interfering with one another.

Why CDMA is not used in satellite communication?

One cannot expect CDMA performance on satellite links comparable to what one can achieve using CDMA on terrestrial links. ... It is shown that because of the length of the round trip propagation delay on a satellite channel, closed-loop power control is not effective.

Why CDMA is more efficient and secure?

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.