KR20030013603A - Method and apparatus for allocating the power gains of reverse power control channels in mobile communication system - Google Patents

Abstract

PURPOSE: A method and an apparatus for assigning a power gain of an RPC(Reverse link Power Control) channel in a mobile communication system are provided to efficiently distribute a limited power assigned in the entire RPC channel and reduce the consumption of an unnecessary power by calculating a channel gain necessary for each channel using a DRC(Data Rate Control) symbol. CONSTITUTION: An RPC channel gain controller(341) determines a channel gain of an RPC channel about each AT(Access Terminal) using DRC symbols received from a plurality of ATs. An RPC channel gain processor(331) multiplies an RPC bit about each ATM by each channel gain from the RPC channel gain controller(341) and outputs the multiplied value. A spreader(332) spreads the output of the RPC channel gain processor(331) as a certain orthogonal code.

Description

METHOD AND APPARATUS FOR ALLOCATING THE POWER GAINS OF REVERSE POWER CONTROL CHANNELS IN MOBILE COMMUNICATION SYSTEM}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile communication system, and in particular, Reverse Link Power Control (hereinafter referred to as RPC) of a mobile communication system using a code division multiple access (CDMA) technique. An apparatus and method for allocating power of a channel.

The radio channel used in the mobile communication system changes the attenuation amount of radio waves according to distance and shadowing, and the interference and fading between systems are severe. Therefore, the carrier to inference ratio (hereinafter referred to as C / I) The change is great. Recently, standards of mobile communication systems that support high-speed data transmission introduce link adaptation schemes that adjust data rates according to channel conditions (receive C / I) in order to increase the throughput of channels. have. The data rate is determined by the coding rate and the modulation method.When the receiving C / I is large, the data rate is increased by using a high coding rate and a high level modulation method. When the receiving C / I is small, the coding rate is low. Using low-level and low-level modulation, the channel reliability is increased instead of lowering the data rate. The receiver predicts the change of the next channel based on the received C / I value and returns the determined data rate to the transmitter. The transmitter assigns the requested data rate for the receiver.

For example, based on 1x Enhanced Version-Data Only (EV-DO) or High Data Rate (HDR) specifications, which are established in the 3rd Generation Partnership Project 2 (3GPP2) to enhance the data services of the cdma2000 1x specification. It will be described as follows. Hereinafter, the 1x Enhanced Version-Data Only (EV-DO) or High Data Rate (HDR) system is referred to as a mobile communication system supporting high-speed data transmission. In the mobile communication system supporting the high speed data transmission, the transmitter becomes an access network (AN) and the receiver becomes an access terminal (AT). The physical layer of the 1x EV-DO with link adaptation is divided into three modulation schemes: Quadrature Phase Shift Keying (QPSK), 8-ary Phase Shift Keying (8PSK), and 16-ary Quadrature Amplitude Modulation (16QAM). And 12 transmission rates according to two coding rates of 1/3 and packet length.

In order to select the transmission rate of the forward link, the base station measures the C / I of the forward pilot channel to determine the transmission rate of the receivable traffic channel and transmits it back. In this case, the feedback data rate control information transmitted is called DRC (Data Rate Control), and the DRC information is transmitted through a DRC channel and is represented by a 4-bit DRC symbol. In addition to the data rate, the terminal indicates a base station sector to transmit data among eight valid sectors as 3 bits of information and transmits the information through the DRC channel. Since the index of the Walsh code covering the DRC channel is determined according to the 3-bit sector information, the above information is referred to as DRC cover.

1 illustrates a transmitter structure of a base station in a mobile communication system supporting high speed data transmission according to the prior art. The transmitter of the base station is largely divided into traffic and control channel transmitters 101 to 108, preamble transmitters 111 to 112, MAC (Media Access Control) channel transmitters 121 to 123, 131 to 134, and pilot channel transmitters 141. And the like.

First, referring to the traffic and control channel transmitter, the encoder 101 encodes and outputs information of an input forward traffic and a control channel. The scrambler 102 scrambles the output of the encoder 101 using a scrambling code and outputs it. The modulator 103 modulates the output of the scrambler 102 using one of QPSK, 8PSK, and 16QAM according to a data rate. The puncturer and repeater 104 punctures and repeats the output of the modulator 103 according to a predetermined rule to match and output a data rate. A symbol demultiplexer 105 demultiplexes the output of the puncturing and repeater 104 into a plurality of parallel channels. The Walsh cover device 106 spreads and outputs each output of the demultiplexer 105 with a Walsh code. The Walsh channel gain processor 107 multiplies and outputs a gain of 1/4 for each Walsh channel. The Walsh Chip Level Summer 108 adds the output of the Walsh channel gain processor 107 to the chip level and outputs it.

Next, look at the preamble transmitter, the preamble signal is given according to the MAC index in the spreader 111 Diffuse to output. The preamble repeater 112 repeatedly outputs the output of the spreader 111 a predetermined number of times according to the data rate.

Next, referring to the MAC channel transmitter, the MAC channel is composed of a reverse activity (RA) channel and a reverse power control (RPC) channel, each of which is coded and transmitted by a 64-walsh code. The RA bit repeater 121 repeatedly outputs a 1-bit reverse activity bit (RAB) by a repetition factor RABLength. The reverse active bit represents the interference load information of the reverse link, and the reverse active bit is transmitted to all terminals in the sector. The RA channel gain processor 122 multiplies the channel gain of the output of the RA bit repeater 121 and outputs the multiplication. The spreader 123 outputs the output of the RA channel gain processor 122. Diffuse to output. The RPC channel gain processor 131 multiplies the input reverse power control (RPC) bit by the channel gain G (i) and outputs the result. The RPC bit represents power control information of the reverse link for the MACindex i-th terminal. The spreader 132 Walsh code the output of the RPC channel gain processor 131. Diffuse to output. The chip level adder 133 adds the output of the diffuser 123 and the output of the diffuser 132 to the chip level and outputs the result. The repeater 127 repeatedly outputs the output of the chip level adder 133 a predetermined number of times per slot (four times). Herein, the transmission power levels in which the respective power gains of the RA channel and the RPC channel are summed are kept the same as the traffic, control channel, and pilot channel.

Next, referring to the pilot channel transmitter, the spreader 141 spreads and outputs a pilot signal, which is always a '0' symbol, with a Walsh code of 0 on an in-phase channel.

A time division multiplexer 151 outputs the output of the traffic and control channel transmitter, the output of the preamble transmitter, the output of the MAC channel transmitter, and the output of the pilot channel transmitter by time division multiplexing according to a predetermined rule. A quadrature spreader 152 complexly spreads the output of the time division multiplexer 151 with a given pseudo-noise (PN) code. The baseband filter 153 performs baseband filtering on the output of the complex spreader 152. The baseband filtered signal is then modulated to the corresponding carrier and then transmitted to the terminal via an antenna. The transmit power level remains constant at the reference transmit power level and the reference transmit power level is generally at the maximum transmit power level of the transmitter.

2A and 2B illustrate a structure of a slot in which forward traffic and control channels, MAC channels, and pilot channels are time-divided in the time division multiplexer 151. 2A shows the structure of an active slot through which traffic and control channels are transmitted. In an active slot, the pilot channel is located at the center of each half slot in the form of two bursts of 96 chips each. In the MAC channel including the RA channel and the RPC channel, a symbol of 64 chips spread by a 64-walsh code is repeatedly transmitted four times before and after each pilot burst. The remainder of the slot consists of traffic and control channels and a total of 1600 chips are transmitted.

2B illustrates a structure of an active slot in which traffic and control channels are not transmitted. In idle slots, only pilot and MAC channels are transmitted. The time-divided forward traffic and control channel, MAC channel, and pilot channel on the forward link are constantly transmitted at the base station's maximum power level.

In the MAC channel, one RA channel and up to 59 RPC channels are code-multiplexed by 64-walsh codes, and each channel is transmitted with a separate channel gain. The RA channel and each RPC channel are assigned MACIndex and are spread by the corresponding 64-walsh code. The RA channel is assigned 4 times, and each RPC channel is assigned a different value between 5 and 63 times for each terminal. do. Since the RA channel is commonly received by all terminals in a sector, when the RA channel is accumulated for RABLength slots, which are repeated arguments, based on the terminal in the cell boundary region, the received energy has a reference RA error performance. The channel gain is determined to satisfy. However, since RPC channels are received by only one specific terminal in a sector for each channel, and the number of channels is up to 59, the performance difference depends on how efficiently the limited power allocated to the entire RPC channel is distributed to each channel. Big. A small RPC channel gain may be allocated to a terminal close to a base station or a channel having good channel environment, but a large RPC channel gain may be allocated to a terminal far from the base station or a channel having poor channel environment. If possible, the minimum channel gain that satisfies the reference error performance for each RPC channel should be allocated to reduce the power consumption more than necessary and increase the number of RPC channels that can be used simultaneously under a limited transmission power. In other words, the number of channels that can be used simultaneously on the forward link and the reverse link should not be limited by the RPC channel.

As described above, in the prior art, there is no specific algorithm for power allocation of the RPC channel, or the same channel gain is allocated to all the RPC channels. In the latter case, the number of RPC channels that can be transmitted at the same time through the code division multiplexing is limited because a larger value is allocated to each RPC channel in consideration of the worst case.

Accordingly, an object of the present invention for solving the above problems is to provide a method and apparatus for power allocation of an RPC channel in a mobile communication system.

Another object of the present invention is to provide a method and apparatus for using a DRC symbol for power allocation of an RPC channel.

Another object of the present invention is to provide a method and apparatus for estimating when a received DRC symbol cannot be obtained and using it for power allocation of an RPC channel.

According to an aspect of the present invention, an apparatus for allocating a gain of an RPC channel of a forward link in a mobile communication system supporting high-speed data transmission includes an RPC channel for the terminal using a DRC symbol received from the terminal. An RPC channel gain controller for determining a channel gain of the RPC channel gain controller, an RPC channel gain processor for multiplying the RPC bit for the terminal by the channel gain from the channel gain controller, and an output of the RPC channel gain processor with a predetermined orthogonal code; And a spreading RPC channel spreader.

According to an aspect of the present invention, an apparatus for allocating a gain of an RPC channel of a forward link in a mobile communication system supporting high-speed data transmission is provided to a specific terminal due to a soft handoff or a DRC erase state at a receiver. If a DRC symbol is not received, a DRC symbol estimator for estimating a current DRC symbol using previously received DRC symbols, and a soft handoff indicator and a DRC erasure indicator are selected to control the selection of the estimated DRC symbol. And a DRC symbol controller and a multiplexer which receives the received DRC symbol and the estimated DRC symbol and selects one by a control signal of the DRC symbol controller and sends the received DRC symbol to the RPC channel gain controller.

According to an aspect of the present invention, there is provided a method for allocating a gain of a reverse power control channel of a forward link in a mobile communication system supporting high speed data transmission, by using a DRC symbol received from a terminal. Determining a channel gain of an RPC channel, multiplying the determined channel gain by the RPC bit for the user, and spreading a signal obtained by multiplying the channel gain by a predetermined orthogonal code.

The present invention for achieving the above object, the method for allocating the gain of the RPC channel of the forward link in a mobile communication system supporting high-speed data transmission, the receiver due to a soft handoff or DRC erase state, etc. Estimating a current DRC symbol using previously received DRC symbols, controlling to select the estimated DRC symbol when a soft handoff indicator and a DRC erasure indicator are input; And receiving one of the received DRC symbol and the estimated DRC symbol and sending one to the RPC channel gain controller based on the control signal.

1 is a diagram illustrating a transmitter structure of a base station in a mobile communication system supporting high speed data transmission according to the prior art.

2A illustrates the structure of an active slot in which traffic and control channels according to the prior art are transmitted;

2B illustrates the structure of an idle slot in which traffic and control channels are not transmitted in accordance with the prior art;

3 is a diagram illustrating a transmitter structure of a base station for allocating power of a reverse power control (RPC) channel using a DRC symbol according to an embodiment of the present invention.

4 is a diagram illustrating a procedure of allocating power of an RPC channel using a DRC symbol according to the first embodiment of the present invention.

5 is a diagram illustrating a procedure for allocating power of an RPC channel using a DRC symbol according to a second embodiment of the present invention.

6 illustrates a DRC symbol estimator in accordance with an embodiment of the present invention.

7 is a diagram illustrating a procedure for controlling a DRC symbol used for power allocation of an RPC channel according to a third embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In describing the operating principles of the preferred embodiments of the present invention in detail with reference to the accompanying drawings, when it is determined that the detailed description of the related well-known functions or configurations may unnecessarily obscure the gist of the present invention, the detailed description will be given. Will be omitted.

3 illustrates a transmitter structure of a base station for allocating power of an RPC channel using a DRC symbol according to an embodiment of the present invention. The present embodiment is characterized in that the RPC channel gain controller is used to calculate the RPC channel gain using the DRC symbol received from the base station receiver and to allocate the power of the RPC channel according to the calculated gain. Hereinafter, the same elements as those of FIG. 1 described in the related art will be omitted and the description will be given based on the parts related to the transmission of the RPC channel. Referring to FIG. 3, a transmitter of a base station receives a demodulated DRC symbol DRC (i) at a receiver for all terminals, that is, all MACIndex i, and sends the demodulated DRC symbol DRC (i) to the RPC channel gain controller 341. The RPC channel gain controller determines the RPC channel gain G (i) for each RPC channel according to the power allocation algorithm of the received DRC (i). The power allocation algorithm is described in detail below. The RPC channel gain processor 331 multiplies each of the RPC channels by the determined RPC channel gain G (i), and the spreader 332 Walsh-codes the output. To spread. The chip level adder 333 outputs the sum of each RPC channel and the RA channel at the chip level, and the repeater 334 repeatedly outputs the output of the chip level adder 333 a predetermined number of times per slot (four times). The multiplexer 361 times-multiplexes and transmits the MAC channel, the pilot channel, the forward traffic, and the control channel in which the RPC channel and the RA channel are combined.

4 shows a procedure of allocating power of an RPC channel using a DRC symbol according to the first embodiment of the present invention.

Referring to FIG. 4, the channel gain controller 341 of the base station transmitter receives the DRC symbol DRC (i) demodulated by the receiver for all terminals in the base station, that is, all MACIndex i in step 401, and receives the DRC (DRC) received in step 402. i) to forward receive pilot C / I (i). The above correspondence is provided in advance in the memory table or calculated by a predetermined algorithm. Table 1 shows an example of the correspondence relationship using the memory table. The memory table uses the same memory table that the terminal uses to determine a data rate, that is, a DRC symbol, by a received pilot C / I in a mobile communication system supporting high speed data transmission.

DRC symbol Data rate Receive Pilot C / I 0x0 38.4 kbps -15 dB 0x1 76.8 kbps -12 dB 0x2 102.4 kbps -9 dB 0x3 153.6 kbps -6 dB 0x4 307.2 kbps (short) -3 dB 0x5 614.4 kbps (short) 0 dB 0x6 307.2 kbps (long) -3 dB 0x7 614.4 kbps (long) 0 dB 0x8 921.6 kbps +3 dB 0x9 1.2288 Mbps +6 dB 0xa 1.8432 Mbps +9 dB 0xb 2.4576 Mbps +12 dB

Using the received pilot C / I (i), the transmission power and the required power gain w (i) required for the MACIndex i RPC channel can be obtained by estimating path loss and interference for the MACIndex i terminal. The required power gain w (i) according to the received pilot C / I (i) must satisfy Equation 1 below. Equation 1 describes an example in which the channel spreading code length used for the RPC channel is "64" and the repetition number of the RPC channel is "4".

The received pilot signal C / I (i) multiplied by the required power gain w (i) becomes the received chip signal-to-interference ratio for the MACIndex i RPC channel, which is decoded for the 64-walsh code and accumulates four repeated MACs, then RPC. Signal energy to interference ratio. Required value of RPC signal energy to noise ratio ensures constant RPC error performance It should be ideal. In step 403, the channel gain controller determines the minimum value satisfying Equation 1 as the required power gain w (i). That is, the required power gain w (i) is obtained as shown in Equation 2 below.

For example, if the received DRC symbol is 0x3 Is 2.0 dB, then C / I (i) is -6dB, that is, 10 ^(-6/10) ≒ 0.2512 according to Table 1 Is a linear scale of 10 ^(2/10) ≒ 1.5849. Therefore, the required power gain w (i) is w (i) = 1.5849 / (0.2512 x 64 x 4) = 0.025 according to Equation 2 above.

W (i) for MACIndex i not allocated to the terminal is set to zero. The sum of the required power gains w (i) calculated for all MACIndex i does not coincide with most of the power gains allocated to the entire RPC channel. If the sum of the required power gains is smaller than the power gains allocated to the entire RPC channel, it does not matter, but if it is large, the power is insufficient and how to allocate the insufficient powers is a problem. Therefore, in this embodiment, the power gain of the entire RPC channel is proportionally allocated to all MACIndex i with the required power gain as a weight. The required power gain weight w '(i) of MACIndex i is the power gain of the entire RPC channel. For Equation 3, the RPC channel gain G (i) calculated from Equation 4 is given by Equation 4. In step 404, the channel gain controller obtains the required power gain weight as shown in Equation 3, and obtains the channel gain G (i) as shown in Equation 4. Since the power gain weight is in power unit and the channel gain is in signal size or amplitude unit, channel gain G (i) is obtained as a square root of the weight.

The channel gain controller sends the obtained RPC channel gain G (i) to the channel gain processor in step 405, and the channel gain processor multiplies each of the RPC channels by the corresponding channel gain. Signals multiplied by the channel gains are code division multiplexed and transmitted over the MAC channel.

5 illustrates a procedure of allocating power of an RPC channel using a DRC symbol according to the second embodiment of the present invention.

The process of calculating the required power gain w (i) (steps 411 to 413) is the same as that of steps 401 to 403 of FIG. 4. As mentioned above, the sum of the required power gain w (i) calculated for all MACIndex i does not match the power gain allocated to the entire RPC channel. In the present embodiment, the channel gain controller assigns power gain as much as the required power gain according to the priority by giving priority to each MACIndex i RPC channel in step 414. At this time, the power gain is allocated according to the priority, and the power gain is not allocated to the RPC channel having a lower priority after the time when the sum exceeds the power gain allocated to the entire RPC channel. If the priority of the RPC channel to which power gain was finally allocated according to the priority is the boundary priority, the RPC channel gain of MACIndex i may be expressed as in Equation 5.

Priority is generally determined in order of increasing data rate in order to increase the throughput of the channel. Conversely, priority may be determined in order of decreasing data rate in order to increase the reliability of the channel. After obtaining the RPC channel gain, the channel gain controller sends the obtained RPC channel gain G (i) to a channel gain processor in step 415, and the channel gain processor multiplies each of the RPC channels by the corresponding channel gain. Signals multiplied by the channel gains are code division multiplexed and transmitted over the MAC channel.

The channel gain may be determined by partially combining the operations according to the first and second embodiments of the present invention. That is, the channel gain may be determined according to the second embodiment up to a predetermined priority, and then the channel gain may be determined according to the weight.

When the terminal is in the soft handoff area, the terminal measures the received pilot C / I of the sectors in the active set and converts the received pilot C / I of the largest sector into the DRC symbol. And the sector is marked with the DRC cover and transmitted. Therefore, the remaining sectors do not obtain the DRC symbol indicating the received pilot C / I for them. In addition, the base station, if the received signal-to-interference ratio of the DRC channel is less than the reference value in order to lower the DRC symbol error probability, abandon the DRC symbol detection and displays the DRC erasure (Erasure) state. As described above, the DRC symbol cannot be obtained in the soft handoff or the DRC erased state and thus cannot be used for the RPC channel gain allocation.

6 illustrates a DRC symbol estimator according to an embodiment of the present invention.

Referring to FIG. 6, the DRC symbol estimator 501 includes a memory capable of continuously storing the received DRC symbols for a predetermined period and performs a predetermined algorithm to estimate and output a new DRC symbol from the stored DRC symbols. DRC symbols stored in the memory are continuously updated. That is, the DRC symbol estimator 501 obtains an estimated value for the DRC _n of the current slot using the DRC symbols (DRC _n-1 , DRC _n-2 , DRC _n-3 ,...) Received in the previous slot. The estimation method will be described in detail below. The multiplexer 503 receives the received DRC symbol and the estimated DRC symbol, selects one from a control signal of a DRC symbol controller 502, and outputs the selected DRC symbol to the RPC channel gain controller. When the DRC symbol controller 502 receives a soft handoff indicator or a DRC erasure indicator, the DRC symbol controller 502 sends a control signal to the multiplexer 503 to select the estimated DRC symbol.

7 illustrates a procedure of controlling a DRC symbol used for power allocation of an RPC channel according to a third embodiment of the present invention.

Referring to FIG. 7, the receiver of the base station demodulates the reverse DRC channel in step 601 to detect the DRC symbol and the DRC cover. In operation 602, it is checked whether the DRC symbol and the DRC cover are in the DRC erased state. For example, if the received signal-to-interference ratio of the DRC channel is smaller than a predetermined reference value, it is determined as a DRC erased state. If the controller is not in the DRC erase state, the controller proceeds to step 603. If the controller is in the erase state, the controller proceeds to step 611.

If not in the DRC erased state, in step 603, the receiver checks whether the detected DRC cover is a cover indicating the sector itself that received the DRC channel. If the detected DRC cover is a cover indicating the sector itself that received the DRC channel, the controller proceeds to step 604, otherwise proceeds to step 621. In step 604, the receiver sends the detected DRC symbol and DRC cover to the RPC channel gain controller. The RPC channel gain controller determines the channel gain to be allocated to the RPC channel by performing the above-described FIG. 4 or 5 by using the received DRC symbol.

On the other hand, if the detected DRC cover is not a cover indicating the sector that received the DRC channel in step 603, the receiver transmits a soft handoff indicator to the DRC symbol controller in step 621. In step 622, the DRC symbol estimator estimates and outputs a DRC symbol using the previously received DRC symbol. In step 623, the DRC symbol controller selects the estimated DRC symbol by the soft handoff indicator and sends the DRC symbol to the RPC channel gain controller of the transmitter. The RPC channel gain controller determines the channel gain to be allocated to the RPC channel by performing the above-described FIG. 4 or 5 by using the received DRC symbol.

In operation 602, the receiver transmits a DRC cancellation indicator to the DRC symbol controller in step 621. In this case, as described above, the DRC symbol estimator estimates and outputs a DRC symbol using the previously received DRC symbol. In step 623, the DRC symbol controller selects the estimated DRC symbol by the DRC erasure indicator and sends it to the RPC channel gain controller of the transmitter. The RPC channel gain controller determines the channel gain to be allocated to the RPC channel by performing the above-described FIG. 4 or 5 by using the received DRC symbol.

The DRC symbol Estimation for DRC symbols received in the previous slot , , , Obtained using When the received pilot C / I value corresponding to the DRC symbol is obtained for each of the DRC symbols received in the previous slot, as shown in Table 1, the received pilot C / I of the slot interval to be estimated can be estimated therefrom.

As an example, as shown in Equation 6 below, the received pilot C / I of the estimated slot interval may be calculated by the division.

DRC symbol of two previously received slots, and Is to divide the received pilot C / I by 1: 2 for It is estimated by the received pilot C / I of. The number and extrapolation ratio of slots to be used for the above estimation can be changed in various ways according to the channel situation as an example. Refer to Table 1 again for the estimated received pilot C / I DRC symbol Estimate

As another example, the received pilot C / I of the estimated slot interval may be calculated using the moving weighted average as shown in Equation 7 below.

DRC symbol of the three slots received previously, and , The received pilot C / I is weighted by 3: 2: 1 for It is estimated by the received pilot C / I of. The number and weight of slots to be used for the above estimation can be changed in various ways according to the channel situation as an example. See Table 1 again for the estimated received pilot C / I. Estimate The DRC symbol estimated in the above manner is sent to the channel gain controller 341. Then, the channel gain controller 341 determines the channel gain to be allocated to the RPC channel by performing the above-described FIG. 4 or FIG. 5 using the estimated DRC symbol.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the scope of the following claims, but also by the equivalents of the claims.

As described above, in the present invention, the effects obtained by the representative ones of the disclosed inventions will be briefly described as follows.

The present invention calculates the channel gain required for each channel by using the DRC symbol to efficiently distribute the limited power allocated to the entire RPC channel, thereby reducing unnecessary power consumption and increasing the RPC channels that can be used simultaneously under the limited transmission power. The advantage is that the channel does not limit the number of channels available on the forward and reverse links. In addition, there is an advantage that the DRC symbol information can be continuously used by estimating the DRC symbol when the DRC symbol cannot be obtained.

Claims (22)

An apparatus for allocating gains of a plurality of reverse link power control (RPC) channels in a forward link of a mobile communication system supporting high speed data transmission, A channel gain controller for determining a channel gain of an RPC channel for each terminal using DRC symbols received from a plurality of terminals at a receiver; A channel gain processor for multiplying and outputting each channel gain from the channel gain controller by the RPC bit for each terminal; And a channel spreader for spreading the output of the channel gain processor with a predetermined orthogonal code. The method of claim 1, wherein the RPC channel gain controller, Receiving a signal to interference ratio (C / I) of a forward pilot corresponding to the received DRC symbol, and calculating the channel gain required for the RPC channel using the obtained received signal to interference ratio; Device. The method of claim 2, The channel gain is calculated by the following equation (8). Here, i denotes the MACIndex of the terminal, and w (i) is the required power gain required for the RPC channel of MACIndex i, Is the required RPC signal energy-to-noise ratio required for the RPC channel to ensure constant error performance, C / I (i) is the received signal-to-interference ratio of the terminal having MACIndex i, and P is the spread used for the RPC channel. Is the length of the sign, Q is the number of repetitions of the RPC channel, w '(i) is the weight of the required power gain for the RPC channel with MACIndex i, Is the power gain allocated to the entire RPC channel, and G (i) is the RPC channel gain for the RPC channel with MACIndex i. The method of claim 2, The channel gain G (i) is calculated by the following equation (9). Here, i denotes the MACIndex of the terminal, and w (i) is the required power gain required for the RPC channel of MACIndex i, Is the required RPC signal energy-to-noise ratio required for the RPC channel to ensure constant error performance, C / I (i) is the received signal-to-interference ratio of the terminal having MACIndex i, and P is the spread used for the RPC channel. Q is the length of the code, and Q is the number of repetitions of the RPC channel, and the boundary rank is the power gain in which the values accumulated by allocating the power gains are allocated to the entire RPC channel when allocating power gains in order according to priority. The priority of the terminal to which the power gain is allocated immediately before exceeding, G (i) is the RPC channel gain for the RPC channel of MACIndex i. The method of claim 2, The channel gain is calculated according to Equation 8 and Equation 9 according to Equation 9 up to a specific rank and after that according to Equation 8 in a subsequent rank. The method of claim 1, wherein the RPC channel gain controller, If the DRC symbol is not available, the received signal-to-interference ratio of the current forward pilot is estimated using previously received DRC symbols, and the channel gain required for the RPC channel is calculated using the estimated received signal-to-interference ratio. Device. The method of claim 6, The received signal-to-interference ratio of the current forward pilot is estimated by dividing the received signal-to-interference ratio of the pilot for two recently received DRC symbols by 1: 2. The method of claim 6, The received signal-to-interference ratio of the current forward pilot is estimated by weighting the pilot received signal-to-interference ratio of three recently received DRC symbols with a weighted average of 3: 2: 1 in the order of the latest reception. Device. The method of claim 1, wherein the receiver fails to receive a DRC for a specific terminal due to a soft handoff or a DRC cancellation state. A DRC symbol estimator for estimating a current DRC symbol using previously received DRC symbols, A DRC symbol controller which controls to select the estimated DRC symbol when a soft handoff indicator and a DRC cancellation indicator are input; And a multiplexer which receives the received DRC symbol and the estimated DRC symbol and selects one by a control signal of the DRC symbol controller and sends the one to a channel gain controller. The method of claim 9, wherein the DRC symbol estimator, And reconstruct the recently received DRC symbols with the signal-to-interference ratio of the forward pilot and to obtain the signal-to-noise ratio of the point that divides the corresponding signal-to-noise ratio by a constant ratio. The method of claim 10, Wherein the ratio of the number of recently received DRC symbols is two and the ratio of the signal-to-noise ratio is 1: 2 from the most recently received DRC symbol. The method of claim 9, wherein the DRC symbol estimator, And recently received DRC symbols are mapped to the signal-to-interference ratio of the forward pilot, and the signal-to-noise ratio is obtained by moving the weighted average of the signal-to-noise ratio with a constant weight to correspond to the DRC symbol to be estimated at present. The method of claim 12, Wherein the number of recently received DRC symbols is three and the weight of signal-to-noise ratio is 3: 2: 1 from the most recently received DRC symbol. A method for allocating gain of a reverse power control channel of a forward link in a mobile communication system supporting high speed data transmission, Determining a channel gain of an RPC channel for the terminal by using a DRC symbol received from the terminal; Multiplying the determined channel gain by the RPC bit for the user; And spreading the signal multiplied by the channel gain with a predetermined orthogonal code. 15. The method of claim 14, wherein the channel gain determination process, Obtaining a received signal-to-interference ratio (C / I) of a forward pilot corresponding to the received DRC symbol; Calculating a channel gain required for the RPC channel using the obtained received signal-to-interference ratio. The method of claim 14, The channel gain is calculated by the following equation (10). Here, i denotes the MACIndex of the terminal, and w (i) is the required power gain required for the RPC channel of MACIndex i, Is the required RPC signal energy-to-noise ratio required for the RPC channel to ensure constant error performance, C / I (i) is the received signal-to-interference ratio of the terminal having MACIndex i, and P is the spread used for the RPC channel. Is the length of the code, Q denotes the number of repetitions of the RPC channel, w '(i) is the weight of the required power gain for the RPC channel of MACIndex i, Is the power gain allocated to the entire RPC channel, and G (i) is the RPC channel gain for the RPC channel with MACIndex i. The method of claim 14, The channel gain is calculated by the following equation (11). Here, i denotes the MACIndex of the terminal, and w (i) is the required power gain required for the RPC channel of MACIndex i, Is the required RPC signal energy-to-noise ratio required for the RPC channel to ensure constant error performance, C / I (i) is the received signal-to-interference ratio of the terminal having MACIndex i, and P is the spread used for the RPC channel. Q is the length of the code, and Q is the number of repetitions of the RPC channel, and the boundary rank is the power gain in which the values accumulated by allocating the power gains are allocated to the entire RPC channel when allocating power gains in order according to priority. The priority of the terminal to which the power gain is allocated immediately before exceeding, G (i) is the RPC channel gain for the RPC channel of MACIndex i. 15. The apparatus of claim 14, wherein the channel gain is calculated according to Equation 10 and Equation 11, up to a specific rank according to Equation 10, and in subsequent ranks according to Equation 11. . 15. The method of claim 14, wherein the channel gain determination process, Estimating the received signal-to-interference ratio of the current forward pilot with previously received DRC symbols if the DRC symbol is not available; Calculating a channel gain required for the RPC channel using the estimated received signal-to-interference ratio. The method of claim 19, The received signal-to-interference ratio of the current forward pilot is estimated by dividing the received signal-to-interference ratio (C / I) of the pilot for two recently received DRC symbols by 1: 2. The method of claim 19, The received signal-to-interference ratio of the current forward pilot is estimated by weighting the pilot received signal-to-interference ratio of three recently received DRC symbols to 3: 2: 1 in the order of recently received and moving weighted average. How to. A method for allocating channel gain of a reverse power control channel transmitted to a plurality of terminals in a mobile communication system supporting high speed data transmission, Obtaining a received signal-to-interference ratio of a forward pilot from DRC symbols received from the plurality of terminals; Calculating the required power gain for the RPC channel of each terminal by estimating the path loss and the interference amount of the forward link from the obtained pilot received signal-to-interference ratio; And calculating the power gain to be allocated to each RPC channel relative to the power allocated to the entire RPC channel by weighting the calculated required power gain for each terminal.