CN1146167C - Power Control Method in Code Division Multiple Access Communication System - Google Patents

Abstract

The invention discloses a power control method in a code division multiple access communication system. A user equipment or a base station stores power control commands from the base station or the user equipment respectively; when the downlink or uplink channel is in the transmission interval of compressed mode, the corresponding uplink or downlink channel is in normal mode or in the non-transmission interval of the compressed mode, the user equipment uses the power control command received from the base station before the transmission interval to estimate the executable power control command of the current time slot, and performs uplink or downlink power control. Compared with the original power control method, this method can estimate the power control trend through the power control command before the transmission interval, and control the power in a predictive way during the period when there is no power control command in the compressed mode, so as to improve the link performance. Effect.

Description

Power Control Method in Code Division Multiple Access Communication System

technical field

The invention relates to mobile communication, in particular to a power control method in a code division multiple access communication system.

Background technique

With the development of mobile communication and the increasing demand for communication, the worldwide focus is on the third generation mobile communication system. The third-generation mobile communication system is a large family composed of different standard systems, including WCDMA, TD-SCDMA, cdma2000 and other protocol standards.

Systems operating on these different standards cannot be isolated from each other, but must be able to interoperate with each other. In addition, GSM will exist for a long time as the 2G system with the widest coverage at present, and the intercommunication between it and the 3G system is also an important issue. However, there are large differences in the protocol specifications of these systems. For example, the uplink and downlink transmission frequencies of each system are different. For WCDMA users, if they want to communicate with users of other systems, they need to switch frequencies. In order to solve the user's inter-frequency handover problem, one solution is to configure dual transceivers for the user, so that the user uses one of them to communicate normally with the GSM Terrestrial Radio Access Frequency Division Duplex Cell (UTRA FDD cell) At the same time, another transceiver can be used to interact with base stations of other systems on different frequencies to prepare for handover. The biggest disadvantage of this method is that its hardware complexity is too high, which leads to an increase in the production cost of the terminal equipment and consumes too much power during use. In order to overcome this shortcoming, the WCDMA system adopts the compressed mode when transmitting up and down.

Set aside some empty time slots in the radio frame for various measurements, this mechanism is called compressed mode, as shown in Figure 1. For the compressed frame including the transmission gap (TG), its transmit power should be increased accordingly to ensure certain quality requirements. The extent to which the transmit power needs to be increased depends on the specific implementation method of the compression mode, and which frames need to be compressed is determined by the network. When using the compressed mode, the compressed frame can appear periodically, or when it can be specified by the upper layer command. In addition, the rate and type of compressed frames are variable, and these changes are determined by the environment and specific measurement requirements.

On the other hand, the superiority of high capacity and high quality of CDMA digital mobile communication system is based on the adoption of many key technologies. Among them, power control is considered to be the core of all key technologies. The purpose of power control is to enable the system to maintain high-quality communication without interfering with other code division channels of the same channel. Both uplink and downlink of the WCDMA system adopt closed-loop fast power control.

Uplink closed-loop power control is that the base station generates a transmission power control (Transmission Power Control, TPC) command for power control according to the strength of the received uplink signal (such as the signal-to-noise ratio SIR value), and transmits it downlink to the user equipment . The principle of downlink closed-loop power control is similar to that of uplink. The user equipment generates a TPC command for power control according to the strength of the received signal (such as the signal-to-noise ratio SIR value), and transmits it uplink to the base station to order it to adjust the power. Let the power control command of the i-th time slot sent by the transmitting end be TPC(i), and the value of TPC(i) is 1 or 0; the executable power control command obtained by the receiving end after judging the received power control command is represented by TPC_cmd( i) indicates that the power is increased when TPC_cmd(i)=1, the power is decreased when TPC_cmd(i)=-1, the power is not adjusted when TPC_cmd(i)=0, and the power control step size is represented by _ΔTPC .

Power control in compressed mode has some different characteristics and is more difficult than in normal transmission mode.

The uplink channel compressed frame format and the downlink channel compressed frame format in the current WCDMA system are shown in Fig. 2 and Fig. 3 .

In compressed mode, the power control method of uplink and downlink dedicated channels can be expressed by the following formula,

Δ _DPCH (i) = P _TPC (i) + P _other (i)

The power adjustment value caused by the power control command is P _TPC (i)=Δ _TPC *TPC_cmd (i), and Δ _TPC is the power adjustment step size brought by the TPC command; in each period before and after the compressed mode transmission interval, Δ D _{The PCH} can be different depending on the algorithm. The power adjustment value caused by other factors such as compressed mode frame structure changes and power balance is Pother(i), which has nothing to do with the TPC command.

When using compressed mode, compressed frames may appear upstream, downstream, or both. Since there is a transmission gap (TG) in the compressed frame, the link signal stops transmitting within the transmission gap (TG), so the power control TPC command cannot be sent, resulting in the loss of the TPC command. The number of lost TPC commands is related to the length of the transmission gap. . Then, within the transmission interval of the uplink compressed frame, downlink power control cannot be performed; and within the transmission interval of the downlink compressed frame, uplink power control cannot be performed. The current solution is to set P _TPC (i)= _ΔTPC *TPC_cmd(i) to 0 when the power control command is lost. This method may cause transmission performance degradation, especially when the transmission interval is relatively long.

Contents of the invention

The purpose of the present invention is to propose the uplink power control method and the downlink power control method under the compressed mode in the code division multiple access communication system in view of the power control command loss in the above-mentioned compressed mode transmission interval, resulting in the situation that power control cannot be performed, During the period when there is no power control command in the compressed mode, the predictive method can be used to control the power, so as to improve the link performance, which is simple and easy.

The uplink power control method in the code division multiple access communication system proposed by the present invention comprises the following steps:

A. The user equipment stores the power control command (TPC(i)) from the base station;

B. When the downlink channel is in the transmission interval of the compressed mode, and the corresponding uplink channel is in the normal mode or in the non-transmission interval of the compressed mode, the user equipment estimates the uplink according to the power control command (TPC(i)) stored in step A The executable power control command (TPC_cmd(i)) of the current time slot of the channel;

C. The user equipment performs uplink power adjustment.

The user equipment storage power control command (TPC(i)) described in step A is to set the power control command memory in the user equipment to store the received current time slot and a total of m power control commands before the current time slot (TPC(i) (i)), m is the memory capacity of the power control command, when the value of the power control command (TPC(i)) is 1, it means that the power needs to be increased, and when the value is 0, it means that the power needs to be reduced.

The executable power control command (TPC_cmd(i)) of estimating the current time slot of the uplink channel described in step B means that the transmission interval of the downlink channel starts from the k+1th time slot, when the user equipment does not receive the power control command , estimate the executable power control command (TPC_cmd(i)) of the current time slot of the uplink channel according to the power control command (TPC(i)) stored before the transmission interval:

When TPC(k-m+1) to TPC(k) are all 1, it is predicted that the current received power is in a deep fading period, and the current power command trend is increasing, then the downlink channel is in the transmission interval of compressed mode, and the corresponding uplink channel is in Normal mode or non-transmission interval in compressed mode, in the first time slot after the start of this situation, the executable power control command TPC_cmd(i)=1 for the uplink channel;

When TPC(k-m+1) to TPC(k) are all 0, it is predicted that the current received power is too high, and the trend of the current power control command is downward, then the downlink channel is in the transmission interval of the compressed mode, and the corresponding uplink channel In the non-transmission interval in the normal mode or in the compressed mode, in the first time slot after the start of this situation, the executable power control command TPC_cmd(i)=-1 of the uplink channel;

When the value of TPC(k-m+1) to TPC(k) is 1 or 0, the downlink channel is in the transmission interval of the compressed mode, and the corresponding uplink channel is in the normal mode or in the non-transmission interval of the compressed mode. The executable power control command TPC_cmd(i)=0 for the uplink channel in the first time slot after the start.

The downlink channel is in the transmission interval of the compressed mode, and the corresponding uplink channel is in the normal mode or in the non-transmission interval of the compressed mode. After the first time slot after the beginning of this situation, every rth time slot after the start, the uplink channel power control adjustment value The value of the executable power control command (TPC_cmd(i)) is the same as the executable power control command (TPC_cmd(i)) of the first time slot; the executable power control command in the uplink channel power control adjustment value in other time slots (TPC_cmd(i)) takes a value of 0 until the user equipment receives the power control command (TPC(i)) from the base station again.

When the user equipment described in step C performs uplink power adjustment, the uplink channel power control adjustment value is the power adjustment value (P TPC (i)) caused by the executable power control command (TPC_cmd(i)) and the power adjustment value (P _TPC (i)) caused by the compressed mode frame The sum of power adjustments (P _other (i)) caused by structural changes and power balance factors. The power adjustment value (P _TPC (i)) caused by the executable power control command (TPC_cmd(i)) is the product of the power control step size (Δ _TPC ) and the executable power control command (TPC_cmd(i)) .

The downlink power control method in the code division multiple access communication system proposed by the present invention comprises the following steps:

D. The base station stores the power control command (TPC(i)) from the user equipment;

E. When the uplink channel is in the transmission interval of the compressed mode, and the corresponding downlink channel is in the normal mode or in the non-transmission interval of the compressed mode, the base station estimates the downlink channel according to the power control command (TPC(i)) stored in step D Executable power control command (TPC_cmd(i)) for the current time slot;

F. The base station performs downlink power adjustment.

The base station storage power control command (TPC(i)) described in the step D is to set the power control command memory at the base station, to store the total n power control commands (TPC(i) before the current time slot and the current time slot received) )), n is the memory capacity of the power control command, when the value of the power control command (TPC(i)) is 1, it means that the power needs to be increased, and when the value is 0, it means that the power needs to be reduced.

The executable power control command (TPC_cmd(i)) of estimating the current time slot of the downlink channel described in step E means that the transmission interval of the uplink channel starts from the k+1th time slot, when the base station does not receive the power control command , estimate the executable power control command (TPC_cmd(i)) of the current time slot of the downlink channel according to the power control command (TPC(i)) stored before the transmission interval:

When TPC(k-n+1) to TPC(k) are all 1, it is predicted that the current received power is in a deep fading period, and the current power command trend is increasing, then the uplink channel is in the transmission interval of compressed mode, and the corresponding downlink channel is in Normal mode or non-transmission interval in compressed mode, in the first time slot after the start of this situation, the executable power control command TPC_cmd(i)=1 for the downlink channel;

When TPC(k-n+1) to TPC(k) are all 0, it is predicted that the current received power is too high, and the trend of the current power control command is downward, then the uplink channel is in the transmission interval of the compressed mode, and the corresponding downlink channel In the non-transmission interval in the normal mode or in the compressed mode, in the first time slot after the start of this situation, the executable power control command TPC_cmd(i)=-1 of the downlink channel;

When the values of TPC(k-n+1) to TPC(k) are 1 or 0, the uplink channel is in the transmission interval of the compressed mode, and the corresponding downlink channel is in the normal mode or in the non-transmission interval of the compressed mode. In the first time slot after the start of the situation, the executable power control command TPC_cmd(i)=0 for the downlink channel.

The uplink channel is in the transmission interval of the compressed mode, and the corresponding downlink channel is in the normal mode or in the non-transmission interval of the compressed mode. In the first time slot after the beginning of this situation, and every sth time slot thereafter, the downlink channel power control adjustment value The executable power control command (TPC_cmd(i)) in the value is the same as the k+1th time slot executable power control command (TPC_cmd(i)); the executable power in the downlink channel power control adjustment value in other time slots The value of the control command (TPC_cmd(i)) is 0 until the base station receives the power control command (TPC(i)) from the base station again.

During the downlink power adjustment by the base station described in step F, the downlink channel power control adjustment value is the power adjustment value (P _TPC (i)) caused by the executable power control command (TPC_cmd (i)) and the compressed mode frame structure The sum of power adjustments (P _other (i)) due to variation and power balance factors. The power adjustment value (P _TPC (i)) caused by the executable power control command (TPC_cmd(i)) is the product of the power control step size (Δ _TPC ) and the executable power control command (TPC_cmd(i)) .

Since the power control method of the present invention adopts the transmission interval when the downlink channel is in the compressed mode, and the corresponding uplink channel is in the normal mode or the non-transmission interval in the compressed mode, the user equipment uses the power control command received from the base station before the transmission interval to estimate The executable power control command of the current time slot is used for uplink power control. When the uplink channel is in the transmission interval of the compressed mode, and the corresponding downlink channel is in the normal mode or in the non-transmission interval of the compressed mode, the base station uses the power control command received from the user equipment before the transmission interval to estimate the executable power control of the current time slot command to perform downlink power control. Compared with the original power control method, this method can estimate the power control trend through the power control command before the transmission interval, and control the power in a predictive way during the period when there is no power control command in the compressed mode, so as to improve the link performance. Effect.

Description of drawings

Figure 1 is a schematic diagram of compressed mode transmission.

Fig. 2 is a schematic diagram of a compressed frame structure of an uplink dedicated channel in a WCDMA system.

Fig. 3 is a schematic diagram of the compressed frame structure of the downlink dedicated channel in the WCDMA system.

Fig. 4 is a schematic diagram of the situation where the downlink channel is in the compressed mode transmission interval and the uplink mode channel is not in the transmission interval involved in the present invention.

Fig. 5 is a schematic diagram of the situation where the uplink channel is in the compressed mode transmission interval and the downlink channel is not in the transmission interval involved in the present invention.

Fig. 6 is a schematic diagram of the case where the compressed mode transmission intervals of the uplink channel and the downlink channel overlap but the boundaries are not aligned according to the present invention.

Detailed ways

As shown in Figure 4, the uplink power control method in the CDMA system proposed by the present invention refers to the transmission interval in the compressed mode when the downlink channel starts from the k+1th time slot, and the length of the transmission interval is L time slots, and At this stage, the corresponding uplink channel is in the normal mode or in the non-transmission interval of the compressed mode, and the power control command memory set in the user equipment stores the power control command from the base station from the k-m+1 time slot to the k-th time slot (TPC(i)), where m is the power control command memory capacity, and the user equipment will estimate the executable power control command (TPC_cmd(TPC_cmd( k+1)).

When TPC(k-m+1) to TPC(k) are all 1, it is predicted that the current received power is in a deep fading period, and the trend of the current power command is increasing, then the executable power control command of the k+1th time slot of the uplink channel TPC_cmd(k+1)=1;

When TPC(k-m+1) to TPC(k) are all 0, it is predicted that the current received power is too high, and the trend of the current power control command is downward, then the executable power control of the k+1th time slot of the uplink channel Command TPC_cmd(k+1)=-1;

When the values of TPC(k-m+1) to TPC(k) are 1 or 0, the executable power control command TPC_cmd(k+1)=0 in the k+1th time slot of the uplink channel.

The user equipment will perform uplink power adjustment according to the executable power control command. The power adjustment is to adjust the transmission power of the k+1th time slot of the channel.

The channel power adjustment value is Δ _DPCH (k+1)＝P _TPC (k+1)+P _other (k+1)

The power adjustment value caused by the power control command is P _TPC (k+1)= _ΔTPC *TPC_cmd(k+1);

_ΔTPC is the power control step size.

The power adjustment value caused by other factors such as compressed mode frame structure changes and power balance is P _other (k+1)

For every rth time slot after the k+1th time slot of the uplink channel, the value of the executable power control command (TPC_cmd(i)) in the uplink channel power control adjustment value is the same as the executable power control command (TPC_cmd(i)) of the k+1th time slot ( TPC_cmd(k+1)) is the same; in other time slots, the executable power control command (TPC_cmd(i)) in the uplink channel power control adjustment value is 0 until the user equipment receives the power control command from the base station again ( TPC(i)).

As shown in Figure 5, the downlink power control method in the code division multiple access system proposed by the present invention refers to the transmission interval when the uplink channel is in the compressed mode from the k+1th time slot, the length of the transmission interval is L time slots, and At this stage, the corresponding downlink channel is in the normal mode or in the non-transmission interval of the compressed mode, and the power control command memory set in the base station stores the power control command from the user equipment from the k-n+1th time slot to the kth time slot (TPC(i)), where n is the power control command memory capacity, and the base station will estimate the executable power control command (TPC_cmd(k +1)).

When TPC(k-n+1) to TPC(k) are all 1, it is predicted that the current received power is in a deep fading period, and the trend of the current power command is increasing, then the executable power control command of the k+1th time slot of the downlink channel TPC_cmd(k+1)=1;

When TPC(k-n+1) to TPC(k) are all 0, it is predicted that the current received power is too high, and the trend of the current power control command is downward, then the executable power control of the k+1th time slot of the downlink channel Command TPC_cmd(k+1)=-1;

When the values of TPC(k-n+1) to TPC(k) are 1 or 0, the executable power control command TPC_cmd(k+1)=0 in the k+1th time slot of the downlink channel.

The base station will adjust the downlink power according to the executable power control command. The power adjustment is to adjust the transmission power of the k+1th time slot of the channel.

The channel power adjustment value is Δ _DPCH (k+1)＝P _TPC (k+1)+P _other (k+1)

The power adjustment value caused by the power control command is P _TPC (k+1)= _ΔTPC *TPC_cmd(k+1);

_ΔTPC is the power control step size.

The power adjustment value caused by other factors such as compressed mode frame structure changes and power balance is P _other (k+1)

For each sth time slot after the k+1th time slot of the downlink channel, the value of the executable power control command (TPC_cmd(i)) in the downlink channel power control adjustment value is the same as the executable power control command (TPC_cmd(i)) of the k+1th time slot ( TPC_cmd(k+1)) is the same; in other time slots, the executable power control command (TPC_cmd(i)) in the downlink channel power control adjustment value is 0 until the base station receives the power control command from the user equipment again ( TPC(i)).

As shown in Figure 6, both the uplink channel and the downlink channel are in compressed mode, and the transmission intervals overlap but the boundaries are not aligned. In Fig. 6, the transmission interval length of the uplink channel is L time slots, which is longer than the transmission interval of the downlink channel. The power control TPC commands of p time slots required for power control of the downlink channel are lost between the straight lines A and B, and between the straight lines C and D The q-slot power control TPC command required for downlink channel power control is lost during the period. The power control at this time adopts the method of the present invention. The executable power control command TPC_cmd of the downlink channel between straight lines A and B and between straight lines C and D is based on the n TPC commands received by the base station from the user equipment before the k+1th time slot shown in straight line A It is estimated that the downlink channel power adjustment is performed every n time slots until the base station receives the TPC command from the user equipment again. When the uplink channel and the downlink channel are in the transmission interval of the compressed mode at the same time, neither the uplink channel nor the downlink channel transmits power, and no power adjustment will be performed.

Claims (10)

1. A method for controlling uplink power in a code division multiple access communication system, characterized in that, comprising the following steps: A. The user equipment stores the power control command (TPC(i)) from the base station; B. When the downlink channel is in the transmission interval of the compressed mode, and the corresponding uplink channel is in the normal mode or in the non-transmission interval of the compressed mode, the user equipment estimates the uplink according to the power control command (TPC(i)) stored in step A The executable power control command (TPC_cmd(i)) of the current time slot of the channel; C. The user equipment performs uplink power adjustment. 2. The uplink power control method in a code division multiple access communication system according to claim 1, characterized in that: the user equipment storage power control command (TPC(i)) described in step A is to set the power control command (TPC(i)) in the user equipment The command memory is used to store the received current time slot and a total of m power control commands (TPC(i)) before the current time slot, where m is the capacity of the power control command memory, and the value of the power control command (TPC(i)) is A value of 1 means that the power needs to be increased, and a value of 0 means that the power needs to be reduced. 3. The uplink power control method in the CDMA communication system according to claim 1, characterized in that: the executable power control command (TPC_cmd(i)) for estimating the current time slot of the uplink channel described in step B is That is, assuming that the transmission interval of the downlink channel starts from the k+1th time slot, when the user equipment does not receive the power control command, it estimates the available power of the current time slot of the uplink channel according to the power control command (TPC(i)) stored before the transmission interval. Execute power control command (TPC_cmd(i)): When TPC(k-m+1) to TPC(k) are all 1, it is predicted that the current received power is in a deep fading period, and the current power command trend is increasing, then the downlink channel is in the transmission interval of compressed mode, and the corresponding uplink channel is in Normal mode or non-transmission interval in compressed mode, in the first time slot after the start of this situation, the executable power control command TPC_cmd(i)=1 for the uplink channel; When TPC(k-m+1) to TPC(k) are all 0, it is predicted that the current received power is too high, and the trend of the current power control command is downward, then the downlink channel is in the transmission interval of the compressed mode, and the corresponding uplink channel In the non-transmission interval in the normal mode or in the compressed mode, in the first time slot after the start of this situation, the executable power control command TPC_cmd(i)=-1 of the uplink channel; When the value of TPC(k-m+1) to TPC(k) is 1 or 0, the downlink channel is in the transmission interval of the compressed mode, and the corresponding uplink channel is in the normal mode or in the non-transmission interval of the compressed mode. The executable power control command TPC_cmd(i)=0 for the uplink channel in the first time slot after the start. The downlink channel is in the transmission interval of the compressed mode, and the corresponding uplink channel is in the normal mode or in the non-transmission interval of the compressed mode. After the first time slot after the beginning of this situation, every rth time slot after the start, the uplink channel power control adjustment value The value of the executable power control command (TPC_cmd(i)) is the same as the executable power control command (TPC_cmd(i)) of the first time slot; the executable power control command in the uplink channel power control adjustment value in other time slots (TPC_cmd(i)) takes a value of 0 until the user equipment receives the power control command (TPC(i)) from the base station again. 4. The uplink power control method in a code division multiple access communication system according to claim 1, characterized in that: when the user equipment described in step C performs uplink power adjustment, the uplink channel power control adjustment value is determined by the executable power The sum of the power adjustment value (P _TPC (i)) caused by the control command (TPC_cmd(i)) and the power adjustment value (P _other (i)) caused by the compressed mode frame structure changes and power balance factors. 5. The uplink power control method in a code division multiple access communication system according to claim 4, characterized in that: the power adjustment value (P _TPC (i) caused by the executable power control command (TPC_cmd(i)) )) is the product of the power control step size ( _ΔTPC ) and the executable power control command (TPC_cmd(i)). 6. A downlink power control method in a code division multiple access communication system, comprising the following steps: D. The base station stores the power control command (TPC(i)) from the user equipment; E. When the uplink channel is in the transmission interval of the compressed mode, and the corresponding downlink channel is in the normal mode or in the non-transmission interval of the compressed mode, the base station estimates the downlink channel according to the power control command (TPC(i)) stored in step D Executable power control command (TPC_cmd(i)) for the current time slot; F. The base station performs downlink power adjustment. 7. The downlink power control method in the code division multiple access communication system as claimed in claim 6, characterized in that: the base station storage power control command (TPC(i)) described in the step D is to set the power control command memory at the base station , to store the received current time slot and a total of n power control commands (TPC(i)) before the current time slot, n is the memory capacity of the power control command, and when the value of the power control command (TPC(i)) is 1 Indicates that the power needs to be increased, and a value of 0 indicates that the power needs to be reduced. 8. The downlink power control method in the code division multiple access communication system according to claim 6, characterized in that: the executable power control command (TPC_cmd(i)) for estimating the current time slot of the downlink channel described in step E is Refers to, assuming that the uplink channel transmission interval starts from the k+1th time slot, when the base station does not receive the power control command, it estimates the executable time of the downlink channel current time slot according to the power control command (TPC(i)) stored before the transmission interval Power Control Commands (TPC_cmd(i)): When TPC(k-n+1) to TPC(k) are all 1, it is predicted that the current received power is in a deep fading period, and the current power command trend is increasing, then the uplink channel is in the transmission interval of compressed mode, and the corresponding downlink channel is in Normal mode or non-transmission interval in compressed mode, in the first time slot after the start of this situation, the executable power control command TPC_cmd(i)=1 for the downlink channel; When TPC(k-n+1) to TPC(k) are all 0, it is predicted that the current received power is too high, and the trend of the current power control command is downward, then the uplink channel is in the transmission interval of the compressed mode, and the corresponding downlink channel In the non-transmission interval in the normal mode or in the compressed mode, in the first time slot after the start of this situation, the executable power control command TPC_cmd(i)=-1 of the downlink channel; When the values of TPC(k-n+1) to TPC(k) are 1 or 0, the uplink channel is in the transmission interval of the compressed mode, and the corresponding downlink channel is in the normal mode or in the non-transmission interval of the compressed mode. In the first time slot after the start of the situation, the executable power control command TPC_cmd(i)=0 for the downlink channel. The transmission interval when the uplink channel is in the compressed mode, and the corresponding downlink channel is in the normal mode or the non-transmission interval in the compressed mode. After the first time slot and every s-th time slot after the beginning of this situation, the downlink channel power control adjustment value is The value of the executable power control command (TPC_cmd(i)) is the same as that of the first time slot executable power control command (TPC_cmd(i)); the executable power control command ( The value of TPC_cmd(i)) is 0 until the base station receives the power control command (TPC(i)) from the base station again. 9. The downlink power control method in a code division multiple access communication system according to claim 6, characterized in that: during the downlink power adjustment of the base station described in step F, the downlink channel power control adjustment value is determined by the executable power control The sum of the power adjustment value (P _TPC (i)) caused by the command (TPC_cmd(i)) and the power adjustment value (P _other (i)) caused by compressed mode frame structure changes and power balance factors. 10. The downlink power control method in a code division multiple access communication system according to claim 9, characterized in that: the power adjustment value (P _TPC (i) caused by the executable power control command (TPC_cmd(i)) )) is the product of the power control step size ( _ΔTPC ) and the executable power control command (TPC_cmd(i)).