How is power control applied in forward CDMA channel?
Power control commands are sent to each subscriber unit on the forward control subchannel which instruct the mobile to raise or lower its transmitted power in 1 db steps. If the received signal is low 0 is sent over power control subchannel instructing the mobile station to increase its mean output power level.
Why is power control used in cdma2000 and WCDMA?
The power control in cdma 2000 and WCDMA is to minimize interference due to presence of other mobile users, fading, log normal shadowing as well as from fast Rayleigh fading. viii. In cdma2000, power control is at the rate of 800Hz in both the links and it is at a rate of 1500Hz in both the links in WCDMA.
What is open loop power control?
As defined in the 3GPP standard TS 34.122 5.4. 1.3, the open loop power control is the ability of the UE transmitter to sets its output power to a specific value. The open loop power control measurement can only be initiated when the Operating Mode is Active Cell and the call status is Idle.
Which hand off used in CDMA?
Soft handover or soft handoff refers to a feature used by the CDMA and W-CDMA standards, where a cell phone is simultaneously connected to two or more cells (or cell sectors) during a call.
What is inner loop control?
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. The UE’s output power changes in response to a single TPC command, TPC_cmd, derived at the UE based on the power control algorithm.
What is power control in UMTS?
Contact Us. UMTS Power Control. Open loop power control is the ability of the UE transmitter to sets its output power to a specific value. It is used for setting initial uplink and downlink transmission powers when a UE is accessing the network.
What is difference between CDMA and Wcdma?
The main difference between WCDMA and CDMA is that they are designed to work with different networks. WCDMA is a 3G technology designed to work alongside the 3G GSM network. CDMA, on the other hand, is a 2G technology that is a direct competitor to GSM.
What is the role of power control 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 control the transmission power of a mobile network?
There are two ways to control the transmission power. First is the open-loop (Open Loop) control and second is closed-loop (Closed Loop) control. In addition to the near-far effect described above, the immediate problem is to determine the transmit power of the mobile when it first establishes a connection.
What is the difference between IS-95 and CDMA?
As specified in the IS-95 standards, mobile acts when it wants to get into the system, it sends a signal called access. In CDMA, each user’s transmission power is allocated by the control power to achieve the same power (Pr) which is received by the base station/BTS with access probe with low power.
How can we reduce the interference of mobile transmitter?
Further, each mobile transmitter power must be controlled to limit the interference. Power control is essentially needed to solve the near-far problem. The main idea to reduce the near-far problem, is to achieve the same power level received by all mobiles to the base station.