An overview of the 3g network umts can in many aspects be looked upon as an extension to gsm and gprs. Characterization of downlink transmit power control during soft handover in wcdma systems palash gupta, hussain mohammed, and m. The average dpdch power is approximately 1 db above the average dpcch power. Wcdma wideband code division multiple access plays the best competitive role in the present world. This paper describes a wideband code division multiple access test system developed by nokia. A power control algorithm for 3g wcdma system researchgate. Wcdma can offer a lot more voice minutes to customers. Inner loop power control in the uplink is the ability of the ue transmitter to adjust its output power in accordance with one or more tpc commands received in the. Power control tpc transmit power control tpc is essential to a cdma architecture. Power control pc is an essential function of cellular.
Wcdma technology provides some advantages for the operator in that it allows the data, but also improves the voice of base. The discussion is general, but often related to concepts and terms in umts based on wcdma radio access networks. The algorithm is based on a modification of the transmitted power update step size. Chapter 3 wideband code division multiple access wcdma 3. Fundamental limitations of power control and radio resource. This means that wcdma networks require a control based on another parameter, in this case a power control for deciding the base station node b that will provide service to mobile terminals, this control. Power control is one of the technologies used to utilize the radio resources as efficient as possible in wcdma. Wcdma a brief overview by ericsson authorstream presentation. Wcdma for umts radio access for third generation mobile communications edited by h a m holma and antti toskala both of nokia, finland john wlley.
User modeling enables in the computation of the traffic density in a cellular network, which can be used to optimize the placement of base stations and radio network controllers as well as to analyze the performance of resource management algorithms towards meeting the final goal. Power control in cdma file exchange matlab central. High power applications up to 35 dbm introduction application note an319, rev. The main target of the uplink power control is to mitigate the nearfar problem by making the transmission power level received from all terminals as good as possible at the home cell for the same qos. Performance analysis of downlink power control in wcdma system dr. Comprehending the technology behind the umts wideband cdma physical layer the physical layer of the universal mobile telecommunications system umts wideband codedivision multiple access wcdma standard uses direct sequence spread spectrum dsss modulation with a chip rate of 3. Wcdma system standardization, interfaces and power control. However, the most common problem for these systems is related to frequency reuse scheme that in 2g networks are the access control parameter. Further, since the objective of the power control algorithm is to keep the ue power spectral density psd constant, total power transmitted by the ue scales with m. Wcdma uses power control to compensate for differences and variations in the. Umts through wcdma can be summarized like a revolution of the air interface accompanied by a revolution in the network of their architecture. Power control in wireless cellular networks mung chiang electrical engineering department, princeton university prashanth hande electrical engineering department, princeton university. Power control in wcdma free download as powerpoint presentation. Maximum downlink signal generation is 10 dbm minimum uplink signal measurement is 70 dbm wcdma gsm handover download latest version file file copy usb usb memory stick cdr usb cd drive start key hard disc lamp power lamp power switch stop.
Delay in chips of the baseband inphase and quadrature square root raised cosine pulse shaping filters, integer, 0 2. Jan 09, 2012 it is the process in which cell tower and mobile phone collectively decide which minimum transmission power a phone could safely employ and still be heard by a cell tower. Nominal power mode according to ul power control settings. Wcdma systems allows to achieve a defined quality of service. Association of power control and data rate selection in wcdma. Gprf power measurement, which is part of the base instrument. Base station bs can estimate proper transmission power by these two power control schemes. In order to maintain the received level at bs, a suitable power control technique must be employed in cdma systems. With algorithm 2, the inner loop power control is performed every five timeslots, that is, the frequency is lower to perform inner loop power control in algorithm 2. School khulna university of engineering and technology. The transmission power is adjusted to transmit with the lowest power level possible while the required received signal quality is maintained. This site is like a library, use search box in the widget to get ebook that you want. The received level fluctuates quickly due to fading.
On the other hand, a higher value of the pilot power level in a cell means higher pilot pollution in the network and less power available to serve user traffic in the cell. Bgs12pl6 spdt rf cmos switch for high power applications. The design contains a lot of flexibility to allow power control at different levels. Impact on quality of service qos of thirdgeneration. Selfoptimizing uplink outer loop power control for wcdma.
Power control in wireless cellular networks princeton university. We need to control the transmission power of each user. Click download or read online button to get wcdma for umts book now. Multiplexing of services with different quality requirements on a single connection, e. For wcdma 2, the european and japanese common proposal for thirdgeneration 1mt2000, power control is defined in 3 for frequencydivision duplex fdd system and 4 for timedivision duplex tdd system. As possible solution for wcdma uplink overload problems, a novel uplink outer loop power control algorithm with dynamic change of. Another is outer loop power control based on one frame time. Because the capacities of the existing networks were nearly exhausted, the demand for new systems was urgent. When we study a new technology one of way to efficiently learnunderstand about it would be to assume that you are the designerdeveloper of the technology and ask yourself now i have this and this problem in such and such situation. Nokia siemens networks flexi multiradio bts is a gsmedge, wcdmaihspa, and lte base station for use in mobile telecommunication antenna networks. Estimation of paper deterioration power transformer diagnostics paktechpoint on oil physical and chemical tests power transformer diagnostics. Maximum output power is verified on the high, middle and low channels according to procedures in section 4.
Uplink power control is used to alleviate the channel fading effect, to adjust the transmit power of the ue so that the signals received at the radio base station. Wcdma wideband code division multiple access, an itu standard derived from code division multiple access cdma is officially known as imt2000 direct spread. When the ue is not in soft handover, only one tpc command is received in each timeslot. A single user downloading a large file can occupy a significant amount of the total cell capacity. Sep 24, 2012 uplink power control determines the average power over a dftsofdm symbol in which the physical channel is transmitted. Power control, broadly speaking, is the intelligent selection of transmitter power output in a communication system to achieve good performance within the system. Download pdf adaptive wcdma free online new books in.
Quintero department of electronic systems aalborg university a thesis submitted for the degree of. During a call, the sir target varies between implemented lower sirmin and upper boundaries sirmax, which are fixed values on radio network control station rnc. Advanced echocancelation allows celfi to transmit more power without feedback interference subscriber devices ue require less transmit power for improved battery life linearity eliminates imd desense issues dynamic gain control ensures maximum gain best coverage at all times in ever changing rf environments, without user intervention. Pilot power is the most important parameter that allows to control the strength of the cpich signal. Power control for power drifting can improve the soft handover performance in the downlink. Introduction power control is essential for the smooth operation of a wcdma system, because all users share the same radio frequency band through the use of different codes. Since there are large variation in channel quality over time, the power has to be adjusted. Wcdma tems parameters investigation and drive testing. Results for at least steps 3, 4 and 10 of the power measurement procedures should be tabulated in the sar report. It is usually set by the use of power control procedure. Important elements of the proposed algorithm are highlighted. Pdf in this paper, an evolution of the power control algorithm is proposed for the thirdgeneration wcdma system. Citeseerx wcdma common pilot power control for load and.
To solve the nearfar problem to increase the system capacity wcdma uses two tpc forms. One is inner loop power control operated in every slot. Here, these are addressed from a control theory perspective. There are two ways to control the transmission power.
The present document summarizes the work carried out at aalborg universitet as mas. Ultra low insertion loss wideband applications introduction application note an332, rev. This is done in gsm via gaussian minimum shift keying gmsk. Adaptive power control has widely been used in dscdma systems to overcome the socalled nearfar problem. Power control occurs 800 times per second values for initial power on access or traffic channels are sent on overhead message on paging channel. This control is called the transmission power control control power. Advanced power control for utran lte uplink nestor j. In dl dpcch, there are always nonzero bits of tpc transmit power control which are used for inner loop power control of the ul dpcch and ul dpdch. Thus, an effective implementation of different power control algorithms in cellular radio communication systems can offer a significant. Fundamental limitations of power control in wcdma, report no. Power control is considered as an important means to combat nearfar fading effects and maintain acceptable connections in wireless communications systems. Where things start to get interesting is with the power dynamics.
They way it takes place in downlink and uplink will become evident in a little bit, as we go further down the discussion. When applying power control in practice, the performance is restricted by a number of fundamental limitations. This standard s adopted by zigbee alliance i to introduce zigbee device which is a low cost, low power, wireless mesh networking standard targeted at wireless control and monitoring applications 5. Sirbased fast closed loop tpc open loop tpc zeon pdf driver trial tw. Capacity and throughput optimization in multicell 3g. Wcdma tems parameters investigation and drive testing 1. Fredrik gunnarsson and fredrik gustafsson, control theory aspects of power control in umts, control engineering practice, volume 11, issue 10, pages 111125, october 2003. In lte, power control takes place both in downlink and uplink. In this paper, an evolution of the power control algorithm is proposed for the thirdgeneration wcdma system.
In wcdma downlink, two power control schemes are operated. Antenna the following 12 minute video shows the teardown step by step with ex. The carrier frequency of the output composite wcdma rf modulated user signal, real, chiprate 2 power of the source, real, 0 pav. Consequently, system load has a substantial impact on the.
So algorithm 2 is applicable when the environment of mobile environment is quite favourable and the channel fades slowly or hardly fade. Jun 18, 2012 power control can be used against shadow fading and fast fading. Scribd is the worlds largest social reading and publishing site. Wcdma power control free download as powerpoint presentation. Because the capacities of the existing networks were nearly exhausted, the. In this paper i will discuss about wcdma system, to know it is standardization, it is interfaces and power control. Power transformer diagnostics sabpp009 download paktechpoint on doble test on insulations power transformer diagnostics. Any of the 2 ports can be used as termination of the diversity antenna or wifi application handling up to 30 dbm. Inner loop power control in the uplink is the ability of the ue to adjust its output power in accordance with one or more tpc transmit power control commands received in the downlink. In the closed loop mode, the mobile station transmitter power is controlled by a signal from the base station. Power control in wcdma broadcast engineering radio. Advanced echocancelation allows celfi to transmit more power without feedback interference subscriber devices ue require less transmit power for improved battery life linearity eliminates imd desense issues dynamic gain control ensures maximum gainbest coverageat all times in ever changing rf environments, without user intervention. Adaptive power control dynamic range algorithm in wcdma. The notion of good performance can depend on context and may include optimizing metrics such as link data rate, network capacity, outage probability, geographic coverage and range, and life of the network and network.
Power control is considered as an important means to combat nearfar fading effects and maintain acceptable connections in wireless. The mobile unit measurement is part of the open loop power control while the base station measurement is part of the closed loop power control. A hashem department of computer science and engineering. Transmitter power control is an efficient technique to mitigate the effect of interference under fading conditions, combat the nearfar problem and conserve the battery life. Voice capacity offered is very high due to interference control mechanisms, including frequency reuse of 1, fast power control, and soft handover. Wcdma wideband code division multiple access, an itu standardderived from code division multiple access cdma is officiallyknown as imt2000 direct spread. The pilot automation improves operability of the network and it is implemented with a control software aiming for load and coverage balancing. Wcdma for umts principles u introduction u cdma background history ucode division multiple access cdma u why cdma. Openloop power control in cdma overlay springerlink. Wcdma is a third generation mobilewireless technology offering much higher data speeds to mobile andportable wireless devices than commonly offered in todaysmarket. Characterization of downlink transmit power control during. Wcdma is a third generation mobile wireless technology offering much higher data speeds to mobile and portable wireless devices than commonly offered in todays market.
R99 downlink power control downlink power control means change of downlink power based on tpc command carried by uplink control channelul dpcch. Config rf settings rf power downlink output channel power ior 93. In contrast to utran based on wcdma however the requirements for ul power control are more relaxed as a similar nearfar problem of utran does not exist. Open loop power control closed loop power control is divided into two main parts. Therefore the picture below should explain you on which channels in dl and ul, power control takes place. Umts requirements multimedia service requirements high data rates at least 384 kbps widearea coverage up to 2 mbps indoor and lowrange outdoor coverage high service flexibility packet and circuitoriented services wide range of bit rates with high granularity multiple services on one. This implies, ue transmit power will change quite considerably between different subframes in lte uplink. Dec 09, 2007 in conclusion, power control is extremely important in umts. Dec 17, 2007 coming to hsupa, the scenario is a little closer to the power control r99 ul channels. Cdma, transmitted power from all links appear as interference, so we. The more power is spent for pilot signals, the better coverage is obtained.
Power control of ul dpdch is closely tied to ul dpcch. The design files of the source components and their associated subcomponents are set out ads designs. To adjust the radiated power of mobile stations in a way that all received signals at the base station have the same signal to interference ratio sir for the same bit. This chapter studies the adaptive openloop power control of a cellular cdma system, which. An effective implementation of different power control algorithms in 3g cellular radio communication systems can offer a significant improvement in the quality of service qos to all the users. Pdf wcdma system standardization, interfaces and power control. Wcdma, power control is employed in both the uplink and the downlink. Comprehesive coverage of umts 3g news, licensing, business developments, 3g wcdma telecommunication technology, multi media mobile phones and future communications. Wcdma system is 3rd generation wireless mobile system specified by 3gpp. Inner power control uenode b outer power control node brnc uplink inner power control downlink innerpower control. The paper validates the feasibility of automating the setting of common pilot power in a wcdma radio network. Compared with utran the ul power control is slower.
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