Signal To Interference Ratio And Network Planning For Cdma System

Jun 29 • Notes • 4508 Views • No Comments on Signal To Interference Ratio And Network Planning For Cdma System

The signal-to-interference ratio (S/I or SIR)

It  is also termed as the carrier to interference ratio (C/I, CIR), it  is the measure among the average received modulate carrier power S or C and the average received co-channel interference power I, i.e. cross-talk, from different transmitters compared to advantageous signal.

The CIR bear a resemblance to the carrier to noise ratio (CNR or C/N), which is the signal-to-noise ratio (SNR or S/N) of a modulated signal before demodulation. A division is that interfering radio transmitters contributing to I may be controlled by radio resource management, while N involve noise power from other source, typically additive white gaussian noise (AWGN).

The CIR ratio is considered in interference partial systems, i.e. where I exist over N, typically in cellular radio systems and propagation systems where frequency channels are reused in view to attain high level of area coverage. The C/N is considered in noise limited systems. If both circumstances can occur, the carrier-to-noise-and-interference ratio, C/(N+I) or CNIR may be studied.

The signal-to-interference ratio (SIR) is a predominant criterion for radio resource management techniques in wireless networks. A lot of algorithms such as power control, channel allocation, and handoff, etc., need a fast and accurate SIR measurement. In performance, however, the SIR estimation needs a lot of computations. The major test for the SIR estimation issue is to find an efficient way to separate the desired signal with interference. We examine the performance of the SIR estimation techniques for the DS-CDMA cellular system in a time-dispersive (or a frequency-selective) fading channel. The major input is to provide a framework incorporating the effect of channel dispersions into the SIR estimator for the CDMA systems. We present new outcome on the quantitative performance of two easily implemented SIR estimation techniques, taking into account the result  of frequency-selective fading, mobility, unlike number of interferers, and different primary transmission power levels

Power of the received signal =1/ (distance from the phone to antenna)2

(This formula applies to both the primary base station as well as the secondary base station.)

Signal to interference ratio-:

Power of the received signal from primary station/ power of received signal from secondary station

Network Planning for CDMA Systems

One of the primary  issues telecommunication operators must face when deploying a cellular network is the radio network planning. The mark of service wireless subscribers experience is dependent on the quality of the radio network planning. Thus, radio network planning is foremost key competence areas for any operator in order to please customers while making the network deal profitable This job presents the essential concepts of radio network planning based on W-CDMA system. It discusses the network dimension. It start with the construction of radio link for W-CDMA system and presents the reverse link budget and the ahead link budget separately. Next, it shows the coverage analysis by means of various propagation models. This is the most essential consideration in the radio coverage planning process. The ability of CDMA can vary within reverse link and forward link because the prerequisite varies with changing conditions. So we give an clarification for capacity theoretical analysis in reverse link and simulation method in forward link. Then we require to estimate the size of the network such as the number of cell sites or cell-count. This task involves setting the highest allowable loading of the system. We focus on the process of radio network planning and the development of a planning tool. A radio network planning tool is an complex software tool that comprises a number of modules that enables an engineer to plan a wireless network. It can give some functions such as the calibration of environment transmission model, automatic searching of cell site, and the forecast of coverage.

Design and implementation of 3G CDMA Infrastructure

Trunking efficiency is also called as channel utilization efficiency an can be calculated as follows:

Efficiency (%) = Traffic in Erlang/ Amount of channel × 100 %

There are three discrete standards operating worldwide

for 3G networks that is WCDMA, CDMA2000 and TDSCDMA, but all have alike planning process as well as overall operational objectives. This planning procedure can be separated into three parts:

1. First phase (also called system dimensioning) involves estimating traffic throughput, coverage region, and coverage threshold.

2. Digital planning phase includes meeting traffic, configuration, coverage threshold and capacity needs.

3. Radio frequency optimization and monitoring; relating coverage verification and capacity availability.

QUESTION & ANSWER

  1. What is signal to interference ratio ??

ANSWER

It is also called as carrier-to-interference ratio (C/I, CIR), it is the measure between the average received modulated carrier power S or C and average received co-channel interference  power I, i.e. is cross talk, from the additional transmitter than the useful signal.

Signal to interference ratio-:

Power of the received signal from primary station/ power of received signal from secondary station

2. What is a trunking efficiency??

ANSWER

Trunking efficiency is also known as channel utilization efficiency and can be calculated as

Efficiency (%) = Traffic in Erlang/ Amount of channel × 100 %

3.  What is a radio network planning??

ANSWER

The mark of service wireless subscribers experience is dependent on the quality of the radio network planning. Thus, radio network planning is foremost key competence areas for any operator in order to please customers while making the network deal profitable This job presents the essential concepts of radio network planning based on W-CDMA system.

 

GATE Syllabus-

1. Gate Syllabus for Electronics and Communication 2014

IES Syllabus-

1. IES Syllabus for General Ability

2. IES Syllabus for Electronics and Telecomm

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