The process feedbacks in figure 3 are shown schematically as one. An example is 28, which adds a term proportional to the time derivative of. Control algorithm for equal current sharing between. Power control and if you want to have some handson experience of these, i would. Icv voltage loop crossover frequency loop and the outer voltage control loop are both simplified, making it much easier to achieve high crossover frequency in both loops. Stability of rate and power control algorithms in wireless. Comparative analysis of power control algorithms for uplink. Optimal implementation of novel wcdma uplink outer loop power.
The pi controllers for the inner and the outer loop are designed using the small statespace averaging technique model and using sisotool in matlab 2528. In 3, wu extended zanders problem formulation to cdma systems by reordering the number of users in different cells. Both the ideal and a more realistic case modeled by including delay, error, and power headroom reporting were. A prerequisite for using this library is basic knowledge of the c programming language, three phase motor drives and power inverter hardware. Loop power control an overview sciencedirect topics. If a dch is configured, the outer loop, which is an implementationspecific algorithm, may continue to. The input stage is typically controlled using an outer voltage loop for bus voltage regulation and an inner control loop to shape the current according to a sinusoidal waveform. In this paper, a new outer loop power control algorithm based on fuzzy theory is proposed. Outer loop power control is used to maintain the quality of communication at the level of bearer service quality requirement, while using as low power as possible. Optimal implementation of novel wcdma uplink outer loop. 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. This is achieved by selecting any one of the test segments referred to as test steps in the standard from the test segment menu and then initiating the measurement. Inner loop control outer loop control received signal measured sir fer target sir transmitter power updown command base station behavior 0.
Finally, the interaction between successive interference cancellation sic receivers at the physical layer and power control, which is a layer 2 radio resource management issue, is studied. To avoid such types of errors, it is often convenient to test the loop with simple i. As possible solution for wcdma uplink overload problems, a novel uplink outer loop power control algorithm with dynamic change of. The block diagram of figure 4 shows the outer and inner control loops for each converter. All gos are encouraged to look at dead bands, droop setting and outer loop controls that may prevent or squelch primary frequency response and take actions to correct.
The parameters of the pi controller for the outer and inner loops are given in table 2. Different parameter settings for this algorithm has been used and evaluated. Control algorithm for equal current sharing between parallel. Closed loop power control is used in wireless communication networks to compensate for fast fading, timevarying channel characteristics, and to reduce mobile battery power consumption. The inner loop controls the sirlevel by changes in the transmission powers. A new power control algorithm for cellular cdma systems. Sirbased power control algorithms for wireless cdma. Open loop power control inner loop power control outer loop power control commercial in confidence 2 20081127 3. Open loop power control closed loop power control is used in combating the fast fading effects, generally caused by multipath fading.
The rnc can use this information as part of the outer loop to set the sir target in the inner loop. The value corresponding with the difference of bler and blertar, processed by fuzzy membership function. Nov 15, 2005 the inner layer is called reverse inner loop power control rilpc, while the outer layer is called reverselink outer loop power control rolpc. The ide tools supported are iar workbench, keil and ac6. Iterative distributed power control dpc, at iteration k. The outer loop controls congestion by setting the sirtarget to the inner loop.
Three types of power control algorithms are employed in wcdma. It is used for setting initial uplink and downlink transmission powers when a ue is accessing the network. Different values of the path loss compensation factor are investigated in the range 0. Further, we combined outer loop power control scheme with the open. An example of application of the adaptive step principle is. Its objective is to maximize capacity by minimizing power and interference. Outer loop inner loop slow fast sir rot rottarget sirtarget channel power fig. Both open and closed loop power control methods are used. Forward power control contains inner loop and outer loop power control, and the inner loop and outer power control work together target fer get from ecam calculate fer set target ebnt value detect forward ebnt insert power control bit. According to the principle of inhibiting resonance by using damping resistance, and using equivalent transformation, a dual loop control strategy for gridconnected inverter with lcl filter was proposed in this paper, this. The current ratio of the parallel circuits can be set arbitrarily. If a dch is configured, the outer loop, which is an implementationspecific algorithm, may continue to operate on the dch only. Pdf the outer loop power control olpc in wcdma systems allows to.
No single variable algorithm such as rss will satisfy. Closed loop power control is used in wireless communication networks to compensate for fast fading and timevarying channel characteristics, and to reduce mobile battery power consumption. Control engineering 61 lecture 6 outer loop setpoint profile generation gain scheduling feedforward and 2dof design system inversion problem feedforward for simple models zero order, first order, second order, oscillatory input shaping iterative update of feedforward runtorun, cascade loop. Therefore, to assist the outer loop power control, the number of retransmissions actually used for transmission of a transport block is signaled from the node b to the rnc.
In this thesis an algorithm for the outer loop power control has been studied and evaluated by simulations in a matlab simulator called curt cdma umts radio network simulator. Dualloop control strategy for gridconnected inverter with. Open loop power control vs closed loop power control. Standardised inner loop power control closed loop power control clpc is available only in dedicated channels in both uplink and downlink. This mechanism is also termed as fast power control as it deals with the fast fading. This paper focuses on innerloop power control techniques which is a category of closed loop power control algorithms in the uplink umts. Therefore, it causes oscillations when the radio channel is unchanged. Pdf power control algorithms in wireless communication. However, existing methods widely use modelbased power optimization algorithms in the outer loop along with linear control techniques in the inner loop. In the closed loop power control, feedback is used for adjusting the transmit power level. Oneshot receive power equalization by bs control 19921993.
Regular paper optimal implementation of novel wcdma uplink outer loop power control algorithm angelo gary markoc. The outer loop adjusts the current reference in order to maintain a regulated bus voltage independently from the. Outer loop power control in a wideband cdma system core. 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. After that, closedloop power control will be applied. Only one or two of the three terms of the pid algorithm might be implemented. The dualloop control method, in which innerloop is the current and outerloop is the voltage, is proposed to design a highefficient precise numerical control parallel power supply system, it operates at input voltage of 24v, output voltage of 612v and output current of 04a. An example of implementation algorithm using dl preamble is shown. The closed loop control structure in is95 one of the currently implemented standards used in wireless networks consists of an outer loop algorithm that. In wcdma frequency division duplex fdd at uplink a feedback control loop is implemented in form of an inner loop power control ilpc and an outer loop power control olpc. Auto mode is used to run a single test segment as specified by 3gpp ts 34. In this thesis we propose a novel power based algorithm for switching between ptp and ptm in order to deliver mbms content with minimum power consumption. When the ue is not in soft handover, only one tpc command is received in each timeslot.
Pdf outerloop power control in a live umts network. Selfoptimizing uplink outer loop power control for wcdma. While outer loop control is set at rrc level and executed at layer 1, fast power control happens at layer 1 in order to meet the bler target set by outer loop control. Speed control for turbinegenerator of orc power generation system and experimental implementation. All gos are encouraged to look at dead bands, droop setting and outer loop controls that may prevent or squelch primary.
Control engineering 61 lecture 6 outer loop setpoint profile generation gain scheduling feedforward and 2dof design system inversion problem feedforward for simple models zero order, first order, second order, oscillatory input shaping iterative update of. Abstractpower optimization and control for gridcoupled wind energy conversion systems wecs has been extensively studied for variable speed wind turbines. Nov 23, 2011 its objective is to maximize capacity by minimizing power and interference. The outer loop control frequency bias algorithm droop and dead band settings must match the droop and dead band settings of the generators. The inner layer, rilpc, typically requires the base station receiver to periodically obtain some measure of the snr being received on a given connection, compare it with a target snr and send a one. The outer loop adjusts the current reference in order to maintain a regulated bus voltage independently from the load or input voltage variations. Power control in the cdma2000 system consists of a reverse link closed loop power control rclpc, a reverse link outer loop power control rolpc, a forward link closed loop power control fclpc. After that, closed loop power control will be applied.
The uplink outer loop power control is responsible for setting a target sir in the node b for each individual uplink inner loop power control. Based on analysis of uplink air interface overload problems, it has been concluded that existing uplink outer loop power. This paper focuses on inner loop power control techniques which is a category of closed loop power control algorithms in the uplink umts. For example, in a buckderived regulator, the current loop has to deal only with the inductor pole, while the output. Scheme over functionality of the outer and inner power control loops. In the proposed algorithm, the voltage set point for the outer voltage loop of converters i and ii are modified as shown in the block diagram of figure 7. A new adaptive power control algorithm for umts communication technologies. A novel outer loop power control algorithm based on fuzzy. In the example above, if we check the loop by printing 1 star, instead of 10 by substituting 10 with 1 in the condition of the loop, we immediately notice that the loop would print 2 stars, instead. Inner loop power control is responsible for adjusting the transmitting power to fulfil the minimum sir target set by outer loop power control. Jul 12, 2012 the control boxes perform pid algorithms. The core of this control algorithm is embedded inside the xcubespn7 and xcubespn8 firmware package available on the st web site. Abstractwe propose a reinforcement learning rl based closed loop power control algorithm for the downlink of the voice over lte volte. There are three types of algorithm for power control, investigated in 410, which are implemented in wcdma system.
You can perform the entire inner loop power control in the uplink test by piecing the test segments together. There are three types of algorithm for power control, investigated in,,,, which are implemented in wcdma system. In this way, overall power control process form a loop closed loop. Power control is a very important in the design of cellular cdma systems which suffer from the nearfar problem. It indirectly controls the uplink and downlink transmit power by increasing or decreasing the target sir value. According to the principle of inhibiting resonance by using damping resistance, and using equivalent transformation, a dualloop control strategy for gridconnected inverter with lcl filter was proposed in this paper, this. Closed loop power control for lte uplink diva portal. Cdma2000 1x power control algorithm telecommunications. The required bler depends on both radio conditions, and. After hsupa power control enhancement is enabled, joint optimization on inner loop and outer loop power control is performed to decrease the interference among nonqossensitive ues.
Deals with power control, channel assignment and handoff decisions. The dual loop control method, in which inner loop is the current and outer loop is the voltage, is proposed to design a highefficient precise numerical control parallel power supply system, it operates at input voltage of 24v, output voltage of 612v and output current of 04a. Power control algorithms in the downlink of the tdd mode and in both link directions of the fdd mode are based on a closedloop control. Umts uplink closed loop power control closed loop power control procedures in umts are standardised by 3gpp 9. During this open loop control, it is assumed that both forward link from bs to ms and reverse link from ms to bs are correlated. Foschini miljanic distributed power control simplest power control solving nearfar problem. Furthermore, it lacks abilities to cope with rapid variations in fast fading channels.
A dualloopbased parallel power supply system scientific. Qlearning algorithm for volte closed loop power control. Stability of rate and power control algorithms in wireless cellular networks. Hence, the power control algorithm aims to reduce transmission power and interference level, and to maximize system capacity. In this paper, we propose a new adaptive power control algorithm for in umts. The lte power control mechanism constitutes of a closed loop component operating around an open loop point of operation. 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. Reverse link outer loop power control with adaptive.
A power control algorithm for 3g wcdma system citeseerx. It happens at a rate of 1500 hz to combat fast fading. Closed loop power control since the forward and reverse links are considered to. Dualloop control strategy for gridconnected inverter.
Power control in wcdma is a closedloop pc which is a combination of outer. The inner layer is called reverse inner loop power control rilpc, while the outer layer is called reverselink outer loop power control rolpc. Umts power control open loop power control is the ability of the ue transmitter to sets its output power to a specific value. Additionally, we propose a new olpc algorithm that shows fast convergence in. This parameter defines the initial sir target value of outer loop power control algorithm. However, existing methods widely use modelbased power optimization algorithms in the outer loop along with. Outerloop power control the outerloop power control is responsible for adjusting the sir target, based on some particular measured parameters such as bler. Sirbased power control algorithms for wireless cdma networks. Power control needs to reduce intercell interference level at the same time achieve a required sinr level. The outer voltage control loop is adjusted by the modified. This approach works well as long as there are sufficiently frequent. The control algorithm for the gridside pwm inverter is illustrated in figure 2.
The closed loop control structure in is95acurrentlyimplemented cdmastandardsusedin wireless networks consists of an outer loop algorithm that. For details of lte specific power control, you have to refer to ts 36. In wcdma frequency division duplex fdd at uplink a feedback controlloop is implemented in form of an inner loop power control ilpc and an outer loop power control olpc. The proposed algorithm can mitigate the oscillations. This closedloop power control is used after an initial phase that uses an openloop power control. Umts uplink closedloop power control closedloop power control procedures in umts are standardised by 3gpp 9. Closed loop power control is needed as estimating the uplink losses based on. Variance minimization stochastic power control in cdma.
Closedloop power control is used in wireless communication networks to compensate for fast fading, timevarying channel characteristics, and to reduce mobile battery power consumption. The inner loop power control located in the node b bases its decision on the sir target set by the outer loop power control located in the rnc. In 3, the outer loop 1 might be a pure p control, loop 2 a pi control, loop 3 another p control, and loop 4 is a p translation to switching times for the pwm. Based on this estimate, the mobile unit adjusts the transmit power accordingly. The outer loop controls congestion by setting the sirtarget to. Comparative analysis of power control algorithms for. Based on analysis of uplink air interface overload problems, it has been concluded that existing uplink outer loop power control has difficulty. Adaptive power control algorithm for 3g cellular cdma. So algorithm 2 is applicable when the environment of mobile environment is quite favourable and the channel fades slowly or hardly fade. The open loop component compensates path loss and shadowing through fractional power control enabling a tradeoff. Umts power control algorithm is based on fixed step size. Ecen 615 methods of electric power systems analysis.
492 1159 642 861 934 976 341 1191 591 936 35 1175 1380 1408 1100 287 558 681 655 574 1353 768 241 694 546 1340 748 111 558 425 434 835 490 285 767