CN100407590C - A method for downlink transmission power control of a base station - Google Patents

Abstract

The invention provides a downlink transmission power control method of a base station, the core of which is: within a predetermined time interval, control the downlink transmission power of the base station according to a predetermined alternating sequence of N power ups and M power downs. The present invention can avoid the abnormal power control of the downlink transmission power of the base station when the uplink wireless link on the base station side is in an out-of-synchronization state, and keep the downlink transmission power of the base station stable, thereby avoiding the call drop phenomenon of the user equipment caused by the abnormal power control, And the phenomenon of interference to other user equipment in the cell, so as to achieve the purpose of improving the capacity of the cell and improving the stability of the network.

Description

A method for downlink transmission power control of a base station

technical field

The invention relates to the technical field of network communication, in particular to a method for controlling downlink transmission power of a base station.

Background technique

In WCDMA (Wideband Code Division Multiple Access) system, the design of TPC (Transmit Power Control) is very important.

On the NODEB (base station) side, for an uplink wireless link, from its establishment to its deletion, it can be divided into three states, namely initial state (initial state), In-sync state (synchronous state) and Out-of-sync state (out of sync state).

When the uplink wireless link on the NODEB side is in the Initial state, the NodeB's transmit power control strategy is: the downlink TPC is maintained, that is, the transmit power of the downlink is required to remain unchanged, and the uplink TPC is TPCPATTERN (transmit power control sequence), that is, the requirement The UE (User Equipment) slowly increases the transmit power to suppress the abnormal increase of RTWP (Base Station Uplink Receive Power).

When the uplink wireless link on the NODEB side is in the In-sync state and Out-of-sync state, the NodeB's transmit power control strategy is: the downlink TPC performs transmit power control according to the UE's requirements, that is, performs DPCCH( Dedicated Physical Control Channel) demodulation, the demodulated downlink TPC directly guides the NodeB to perform downlink power control; the uplink TPC estimates the SIR (signal-to-interference ratio) of the received signal through the UE and compares it with the target SIR to generate an uplink The TPC is used to precisely adjust the transmit power of the UE.

When the uplink wireless link on the NODEB side is in an out-of-sync state, the uplink wireless link may think that it has found multipath due to the generation of virtual paths. In order to reduce the power or maintain the power, there is a certain degree of randomness, which makes the downlink transmission power of the base station highly uncertain.

When the downlink TPC demodulated according to the virtual path is all increased power, it may cause downlink congestion, thereby affecting the capacity of the cell; when the downlink TPC demodulated according to the virtual path is all reduced power, it may cause the UE downlink to be out of sync , thus causing call drop and making the stability of the network poor.

Contents of the invention

The object of the present invention is to provide a method for controlling downlink transmission power of a base station, so as to avoid abnormal power control of the downlink transmission power of the base station, thereby achieving the purpose of improving cell capacity and network stability.

In order to achieve the above object, the present invention provides a method for downlink transmission power control of a base station, the method comprising:

When the uplink wireless link on the base station side is in an out-of-synchronization state, the downlink transmit power of the base station is controlled according to a predetermined alternate sequence of N power ups and M power downs.

The N and M are positive integers greater than zero, and the N is greater than M.

The method further comprises:

When the uplink radio link at the base station side is in an out-of-synchronization state, the downlink transmit power of the base station is controlled according to the transmit power control sequence pattern and the alternating sequence of L boost powers.

Said L comprises: 1.

The method also includes:

When the uplink wireless link on the base station side changes from an out-of-synchronization state to a synchronous state, the downlink transmission power of the base station is determined and controlled according to the dedicated physical control channel of the multipath phase.

It can be clearly known from the description of the above technical solution that the present invention controls the downlink transmission power of the base station according to the predetermined alternating sequence of power up and power down when the uplink wireless link on the base station side is in an out-of-synchronization state, so that the downlink transmission power of the base station It can rise slowly, effectively preventing the out-of-synchronization phenomenon of the uplink wireless link on the base station side, and effectively suppressing the abnormal power control phenomenon of the downlink transmission power of the base station when the uplink wireless link is in an out-of-synchronization state, so that the downlink transmission power of the base station can be maintained Stable, avoiding the phenomenon of user equipment call drop caused by abnormal power control, and the phenomenon of interference to other user equipment in the cell, so that the purpose of improving the capacity of the cell and improving the stability of the network is realized through the technical solution provided by the present invention.

Description of drawings

FIG. 1 is a flow chart of a method for controlling downlink transmission power of a base station in an out-of-synchronization state according to the present invention.

Detailed ways

When the uplink wireless link on the base station side is out of synchronization, if the downlink transmit power of the base station is not controlled according to the downlink transmit power demodulated by the dedicated physical control channel of the virtual path, but the slowly rising transmit power is used to control the downlink transmit power of the base station Controlling the downlink transmission power of the base station can avoid abnormal power control of the downlink transmission power of the base station, thereby avoiding downlink congestion and call drop of the user equipment.

Therefore, the core of the present invention is to control the downlink transmission power of the base station according to the predetermined alternating sequence of N power ups and M power downs within a predetermined time interval.

The technical solution provided by the present invention will be further described below based on the core idea of the present invention.

When the uplink wireless link on the base station side is in an out-of-synchronization state, no matter whether there is a virtual path in the uplink wireless link on the base station side, the present invention does not affect the downlink transmit power of the base station according to the downlink transmit power demodulated by the multipath dedicated physical control channel. Instead, the slowly rising transmit power is used to control the downlink transmit power of the base station.

The implementation method for the base station to control its downlink transmission power with slowly rising transmission power is as follows: the base station controls the downlink transmission power of the base station in a predetermined alternate sequence of N power ups and M power downs.

Where: N and M are positive integers greater than zero, and N is greater than M.

In the above description, there are many ways to realize the predetermined alternating sequence of N power ups and M power downs, which may specifically include: adopting the TPC PARTTEN (transmission power control sequence) mode and the alternating sequence of L power ups, etc.

When L is 1, if TPC PARTTEN is 14, then after 14 sets of power reduction and power increase, a power increase is added, which is approximately equivalent to an increase of 50db per second, that is, the control step size of the downlink transmit power is 1db.

When the uplink wireless link on the base station side is out of sync, the base station uses slowly rising power to control its downlink transmission power, which can effectively prevent the uplink wireless link on the base station side from being out of sync due to the uplink wireless link on the user equipment side being out of sync. phenomenon, thereby avoiding the phenomenon of user equipment call drop.

When the uplink wireless link on the base station side changes from the out-of-sync state to the synchronous state, it should return to the normal TPC generation method, that is, the downlink TPC of the base station is demodulated according to the DPCCH of the correct multipath phase, and the downlink TPC of the base station is obtained according to the demodulated The downlink TPC of the base station controls the transmit power of the downlink radio link of the base station.

The method for controlling the downlink transmission power of the base station in the out-of-synchronization state of the uplink wireless link on the base station side of the present invention will be described below with reference to FIG. 1 .

In Fig. 1, at step 100, the state of the uplink wireless link at the base station side changes from a synchronous state to an out-of-synchronization state.

In step 110, the downlink transmission power of the base station is controlled by using the alternate sequence of TPC PARTTEN mode and L power ups, such as adding a power up after 14 sets of power downs and power ups to control the downlink transmission power of the base station.

Go to step 120, judge whether the state of the uplink wireless link on the base station side changes to a synchronous state by an out-of-synchronization state, if it does not change to a synchronous state, continue to control the downlink transmission power of the base station according to the method in step 110, until the base station side The state of the uplink wireless link changes from an out-of-synchronization state to a synchronous state.

Go to step 130, demodulate the downlink TPC of the base station according to the DPCCH of the correct multipath phase, and control the transmit power of the downlink wireless link of the base station according to the demodulated downlink TPC of the base station.

While the invention has been described by way of example, those skilled in the art will appreciate that there are many variations and changes to the invention without departing from the spirit of the invention, and it is intended that such variations and changes be covered by the appended claims.

Claims (4)

1. the method for a base station down transmitting power control is characterized in that, comprising:

The up-link wireless link of base station side be in desynchronizing state during, according to N power per liter and M predetermined alternating sequence that falls power the down transmitting power of base station is controlled; Described N, M are the positive integer greater than zero, and described N is greater than M.

2. the method for a kind of base station down transmitting power control as claimed in claim 1 is characterized in that described method further comprises:

When base station side up-link wireless link is in desynchronizing state, the down transmitting power of base station is controlled according to the alternating sequence of transmitting power control sequence pattern and L power per liter.

3. the method for a kind of base station down transmitting power control as claimed in claim 2 is characterized in that described L comprises: 1.

4. as the method for claim 1,2 or 3 described a kind of base station down transmitting power controls, it is characterized in that described method also comprises:

When base station side up-link wireless chain route desynchronizing state changes synchronous regime into, determine the down transmitting power of base station according to the Dedicated Physical Control Channel of multipath place phase place, and control.

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