EP1354433A1 - Adaptive pilot/traffic channel power control for 3gpp wcdma - Google Patents

Adaptive pilot/traffic channel power control for 3gpp wcdma

Info

Publication number
EP1354433A1
EP1354433A1 EP20010992407 EP01992407A EP1354433A1 EP 1354433 A1 EP1354433 A1 EP 1354433A1 EP 20010992407 EP20010992407 EP 20010992407 EP 01992407 A EP01992407 A EP 01992407A EP 1354433 A1 EP1354433 A1 EP 1354433A1
Authority
EP
European Patent Office
Prior art keywords
method
power ratio
represents
reference power
recited
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP20010992407
Other languages
German (de)
French (fr)
Inventor
Robert C. Qiu
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Intel Corp
Original Assignee
WISCOM TECHNOLOGIES INC
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to US25826000P priority Critical
Priority to US258260P priority
Application filed by WISCOM TECHNOLOGIES INC filed Critical WISCOM TECHNOLOGIES INC
Priority to PCT/US2001/050552 priority patent/WO2002052757A1/en
Publication of EP1354433A1 publication Critical patent/EP1354433A1/en
Application status is Withdrawn legal-status Critical

Links

Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W52/00Power management, e.g. TPC [Transmission Power Control], power saving or power classes
    • H04W52/04TPC
    • H04W52/30TPC using constraints in the total amount of available transmission power
    • H04W52/32TPC of broadcast or control channels
    • H04W52/325Power control of control or pilot channels
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W52/00Power management, e.g. TPC [Transmission Power Control], power saving or power classes
    • H04W52/04TPC
    • H04W52/06TPC algorithms
    • H04W52/16Deriving transmission power values from another channel
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W52/00Power management, e.g. TPC [Transmission Power Control], power saving or power classes
    • H04W52/04TPC
    • H04W52/18TPC being performed according to specific parameters
    • H04W52/28TPC being performed according to specific parameters using user profile, e.g. mobile speed, priority or network state, e.g. standby, idle or non transmission
    • H04W52/288TPC being performed according to specific parameters using user profile, e.g. mobile speed, priority or network state, e.g. standby, idle or non transmission taking into account the usage mode, e.g. hands-free, data transmission, telephone
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W52/00Power management, e.g. TPC [Transmission Power Control], power saving or power classes
    • H04W52/04TPC
    • H04W52/38TPC being performed in particular situations
    • H04W52/50TPC being performed in particular situations at the moment of starting communication in a multiple access environment

Abstract

The present invention is a method (figure 1) and system to determine the gain factors for the uplink and downlink Dedicated Physical Control Channel (DPCC) and Dedicated Physical Data Channel (DPDC). The method consists of determining new data rate (104) for transmission; providing corresponding system and radio channel parameters (106); determining reference power ratio P1 (108); and, normalizing the reference power ratio (110).

Description

ADAPTIVE PILOT/TRAFFIC CHANNEL POWER CONTROL FOR 3GPP

WCDMA

FIELD OF THE INVENTION

This invention relates to the field of wireless digital communications, and more particularly to gain factors.

BACKGROUND OF THE INVENTION

Wireless communications facilitates the delivery of information between the transmitter and the receiver without a physical wired connection. Such advantage translates to the freedom of mobility for the users and to the savings of wiring nuisance for the users. However, spectrum has become scarce resource as the usage of wireless communications for various applications becomes more popular. Therefore the efficiency of using spectrum presents challenges for the wireless industry. In order to maximize efficient spectrum utilization, various multiple access methods have been proposed to achieve the goal. First generation cellular communications systems, Advanced Mobile Phone

Services (AMPS) employed the Frequency Division Multiple Access (FDMA) method and provided voice communication services in the early days. Second generation cellular communications systems improved the spectrum efficiency by using more digital processing of signals and employed Time Division Multiple Access (TDMA) method in GSM and IS-136 systems and Code Division Multiple Access (CDMA) method in IS-95 systems. While second generation systems typically provide two to five times voice capacity over the first generation systems, data capabilities of second-generation systems are very limited. Recent rapid commercial development of Internet and multimedia applications has created a strong demand for wireless cellular systems capable of providing sufficient bandwidth. In addition, further improvement of voice capacity in spectrum efficiency is in great demand as the spectrum allocated for service is very limited. This scarcity results in high licensing fees for the available spectrum.

Therefore there is a strong need to improve the system capacity and spectrum efficiency for wireless communication systems.

SUMMARY OF THE INVENTION

The present invention is a method and system to determine the gain factors for the uplink and downlink Dedicated Physical Control Channel (DPCC) and Dedicated Physical Data Channel (DPDC).

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the present invention may be obtained from consideration of the following description in conjunction with the drawing in which Fig. 1 is a functional block diagram.

DETAILED DESCRIPTION OF AN EXEMPLARY EMBODIMENT

The present invention is equally well suited for both uplink of WCDMA as well as other similar systems like CDMA2000. One feature of the present invention is a method and system to determine the gain factors for the uplink and downlink DPDCH and DPCCH. This method and system is equally well suited for Physical Random

Access Channel (PRACH) message part. The uplink Dedicated Physical Control Channel (DPCCH) and Dedicated Physical Data Channel (DPDCH) are transmitted on different codes. The gain factors βc and βd are important to 3GPP WCDMA system performance like capacity.

The initial uplink DPCCH transmit power is set by higher layers. Subsequently the uplink transmit power control procedure simultaneously controls the power of a

DPCCH and its corresponding DPDCHs (if present). The relative transmit power offset between DPCCH and DPDCHs is determined by the network and is computed using the gain factors signaled to the User Equipment (UE) using higher layer signaling.

There are two ways of controlling the gain factors of the DPCCH code and the DPDCH codes for different Transport Format Combinations (TFCs) in normal (non- compressed) frames:

- βc and βd are signalled for the TFC, or

- βc and βd is computed for the TFC, based on the signalled settings for a reference TFC.

Combinations of the two above methods may be used to associate βc and βd values to all TFCs in the TFCS. The gain factors may vary on radio frame basis (1 radio frame = 10 ms) depending on the current TFC used. Further, the setting of gain factors is independent of the inner loop power control.

The operation of the inner power control loop, adjusts the power of the DPCCH and DPDCHs by the same amount, provided there are no changes in gain factors. Additional adjustments to the power of the DPCCH associated with the use of compressed mode. Any change in the uplink DPCCH transmit power shall take place immediately before the start of the pilot field on the DPCCH. The change in DPCCH power with respect to its previous value is derived by the User Equipment and is denoted by ΔDPCCH (in dB). The previous value of DPCCH power shall be that used in the previous slot, except in the event of an interruption in transmission due to the use of compressed mode, when the previous value shall be that used in the last slot before the transmission gap.

During the operation of the uplink power control procedure the User Equipment transmit power shall not exceed a maximum allowed value which is the lower out of the maximum output power of the terminal power class and a value which may be set by higher layer signaling. Uplink power control shall be performed while the User Equipment transmit power is below the maximum allowed output power. If the User Equipment transmit power is below the required minimum output power [as defined in TS 25.101] and the derived value of ΔDPCCH is less than zero, the User Equipment may reduce the magnitude of ΔDPCCH- The User Equipment shall scale the total transmit power of the DPCCH and

DPDCH(s), such that the DPCCH output power follows the changes required by the power control procedure with power adjustments of ΔDPCCH dB, unless this would result in a User Equipment transmit power above the maximum allowed power. In this case the User Equipment shall scale the total transmit power so that it is equal to the maximum allowed power.

The gain factors during compressed frames are based on the nominal power relation defined in normal frames. When the gain factors βc and β are signaled by higher layers for a certain TFC, the signaled values are used directly for weighting of DPCCH and DPDCH(s). The variable Aj, called the nominal power relation is then computed as:

A = — Equation 1.

Typically each TFC has a unique data rate connected with a unique pair of gain factors for the DPCCH and DPDCH. The change of gain factors for DPCCH and DPDCH are performed to keep constant the transmitted bit energy ED (before coding) on the DPDCH, independent of the data rate. The DPCCH power is kept constant to avoid affecting the transmit power control (TPC). If the power ratio between DPDCH and DPCCH goes wrong, the TPC loop operating based on DPCCH will degrade the WCDMA system performance.

The present invention provides a method and system to determine the gain factors for the uplink DPDCH and DPCCH.

In Equation 2, m represents number of paths, P represents reference power ratio, Ro represents cutoff rate, ro represents coding rate, Bn represents the noise bandwidth, and, Rb represents information bit rate. A key concept of the present invention is to link up the nominal power relation in Equation 1 with both system and radio channel parameters through the closed form relationship given by Equation 2. Referring to the functional diagram in Fig. 1 there can be seen an illustration of the use of the present invention in the form of a functional block diagram to set up the normalized reference power ratio. By using an example the working principle behind the present invention can be better illustrated. In Step 102 we use the corresponding reference power ratio for voice (Most times the system parameters are optimized for voice performance and for a WCDMA system the initial focus is voice applications) as the initial value of Po. When the system is required to serve a new data rate, say r=384kbps, we need to figure out what the new nominal power relation in Equation 1. The method illustrated in Fig. 1 is used to obtain the new A). This new At can be used by the system to set up the signaled gain factors for the reference TFC. The settings can be sent through higher layers for a certain TFC. What really matters is the relative settings of one data rate to another initial data rate such as a voice channel. The relative settings play an important role in "'calibrating" the system settings. If there is a system error in Equation 2, this scaling can reduce the error such that the relative settings can more accurately describe the functional relationship between one DPDCH data channel and another DPDCH data channel. In step 102 an initial value is given to A0. The data rate in step 104 is given. In step 106 the necessary system and radio channel parameters necessary for Equation 2 are given. The reference power ratio Pι=P is solved using Equation 2 in step 108. The normalized reference power ratio is determined in step 110. Steps 104 through 110 are dynamically repeated for new data rate. In the present invention, the dynamic nature of the radio channel is directly related to the dynamic nature of the DPDCH data channel. Therefore the present invention responds quickly to the radio channel of the air interface while the mobile terminal is moving around. No simple scheme in power settings can be accurate without dynamic response to the real-time radio channel being experienced by the DPDCH data channel and the DPCCH channel. Thus this scheme can be regarded as the adaptive scheme for the system to set up the resources to make certain that the WCDMA system works at an optimal state. The significance of this method is the speed of the quick convergence. Although it may not be so accurate for some working conditions, the method is Fig. 1 dynamically adjust the nominal power relation quickly. Thus the system is always working at the quasi-optimal system settings. One result of the net advantages of this method is that the system resource or system power is not wasted and thus the interference is minimized. These two interacting factors both lead to higher system throughput or system capacity.

In view of the foregoing description, numerous modifications and alternative embodiments of the invention will be apparent to those skilled in the art. The present invention is equally well suited for both uplink of WCDMA and similar systems like

CDMA2000. One feature of the present invention is a method and system to determine the gain factors for the uplink and downlink DPDCH and DPCCH. This method and system is equally well suited for Physical Random Access Channel (PRACH) message part. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the best mode of carrying out the invention. Details of the structure may be varied substantially without departing from the spirit of the invention, and the exclusive use of all modifications, which come within the scope of the appended claim, is reserved.

Claims

I claim:
1. A method for adaptive pilot/traffic channel power control in a CDMA communication system, the method comprising Ijhe following steps: determining new data rate for transmission; providing corresponding system and radio channel parameters; determining reference power ratio Pi; and, normalizing the reference power ratio.
2. The method as recited in claim 1 further comprising the step of assigning an initial power ratio An.
3. The method as recited in claim 2 wherein said initial power ratio Ao is for voice.
4. The method as recited in claim 1 wherein the reference power ratio is determined by
wherein m represents number of paths; P represents reference power ratio; Ro represents cutoff rate; ro represents coding rate; B„ represents the noise bandwidth; and, Rb represents information bit rate.
5. The method as recited in claim 1 wherein the normalized reference power ratio is determined by A, = (Pι/P0)*Ao.
6. The method as recited in claim 1 further comprising repeating the steps for each new data rate.
7. The invention as substantially described and shown herein.
EP20010992407 2000-12-22 2001-12-21 Adaptive pilot/traffic channel power control for 3gpp wcdma Withdrawn EP1354433A1 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
US25826000P true 2000-12-22 2000-12-22
US258260P 2000-12-22
PCT/US2001/050552 WO2002052757A1 (en) 2000-12-22 2001-12-21 Adaptive pilot/traffic channel power control for 3gpp wcdma

Publications (1)

Publication Number Publication Date
EP1354433A1 true EP1354433A1 (en) 2003-10-22

Family

ID=22979778

Family Applications (1)

Application Number Title Priority Date Filing Date
EP20010992407 Withdrawn EP1354433A1 (en) 2000-12-22 2001-12-21 Adaptive pilot/traffic channel power control for 3gpp wcdma

Country Status (3)

Country Link
EP (1) EP1354433A1 (en)
CA (1) CA2436042A1 (en)
WO (1) WO2002052757A1 (en)

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US7295857B2 (en) 2002-10-30 2007-11-13 Qualcomm Incorporated Method and apparatus for performing acquisition in power save mode for wireless communication systems
DE10306453A1 (en) * 2003-02-17 2004-08-26 Deutsche Telekom Ag Wireless data exchange method in which administrator is used to automatically connect mobile terminal or terminals in optimum manner via available network connection according to required bandwidth
JP2004297231A (en) * 2003-03-26 2004-10-21 Nec Corp Mobile communication system, radio base station apparatus and power control method used for them
KR100996079B1 (en) 2003-09-03 2010-11-22 삼성전자주식회사 Method and apparatus for controling reverse tpr in mobile telecommunication system
US7630731B2 (en) 2003-09-08 2009-12-08 Lundby Stein A Apparatus, system, and method for managing reverse link communication
US7724701B2 (en) 2003-09-30 2010-05-25 Qualcomm Incorporated Method and apparatus for controlling reverse link data rate of a mobile station in a communication system with reverse link common rate control
GB2408420B (en) * 2003-11-21 2006-05-10 Motorola Inc Method of power control and corresponding power controller
US8452316B2 (en) * 2004-06-18 2013-05-28 Qualcomm Incorporated Power control for a wireless communication system utilizing orthogonal multiplexing
GB0420847D0 (en) 2004-09-20 2004-10-20 Koninkl Philips Electronics Nv A radio communication system, a radio station, and a method of transmitting data
CA2535189C (en) 2005-02-04 2011-04-12 Samsung Electronics Co., Ltd. Method and apparatus for setting gain factors for dedicated physical channels in a mobile telecommunications system
US8848574B2 (en) 2005-03-15 2014-09-30 Qualcomm Incorporated Interference control in a wireless communication system
US8942639B2 (en) 2005-03-15 2015-01-27 Qualcomm Incorporated Interference control in a wireless communication system
KR100827117B1 (en) * 2005-03-29 2008-05-02 삼성전자주식회사 Method and apparatus for signalling of maximum ue transmitter power information to basestation for the scheduling of uplink packet transmission in a mobile communication system
EP1941642A1 (en) * 2005-10-27 2008-07-09 QUALCOMM Incorporated A method and apparatus for setting reverse link cqi reporting modes in wireless communication system
JP5430938B2 (en) 2005-10-27 2014-03-05 クゥアルコム・インコーポレイテッドQualcomm Incorporated Method and apparatus for estimating reverse link loading in a wireless communication system
US8036151B2 (en) 2006-12-17 2011-10-11 Qualcomm Incorporated Power-based rate signaling for cellular uplink
CN101820649B (en) * 2010-05-18 2014-10-22 中兴通讯股份有限公司 Enhanced dedicated transport channel transport format combination selection method and system
US8682377B1 (en) 2010-08-26 2014-03-25 Sprint Spectrum L.P. Systems and methods for adjusting the power control settings in a wireless communication network

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US5267262A (en) * 1989-11-07 1993-11-30 Qualcomm Incorporated Transmitter power control system
US5710758A (en) * 1995-09-29 1998-01-20 Qualcomm Incorporated Wireless network planning tool
US5771461A (en) * 1996-06-28 1998-06-23 Motorola, Inc. Method and apparatus for power control of a first channel based on a signal quality of a second channel

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Also Published As

Publication number Publication date
WO2002052757A1 (en) 2002-07-04
CA2436042A1 (en) 2002-07-04

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