KR100689431B1 - Apparatus and method for controlling an automatic gain controller due to a compressed mode - Google Patents

Abstract

The present invention provides an asynchronous mobile communication system that supports a compression mode that performs a transmission blank interval operation, which is a signal measurement interval according to a handover between base stations using different frequency bands. Correcting power, generating a standard error that is a difference between the corrected received power and a target received power, multiplying the standard error by a gain constant, and accumulating a signal multiplied by the standard error and the gain constant for a predetermined period Generates the automatic gain control signal, detects a transmission blank section according to the compression mode, and generates the gain constant so that the automatic gain controller operates in a capture mode at a start time and an end time of the transmission blank section.

AGC, capture mode, tracking mode, compressed mode, DTX

Description

APPARATUS AND METHOD FOR CONTROLLING AN AUTOMATIC GAIN CONTROLLER DUE TO A COMPRESSED MODE

1 is a diagram schematically illustrating a transmission structure according to performing a compressed mode in a conventional UMTS communication system.

2A to 2C schematically illustrate an operation of applying an offset to a transmission power when performing a compressed mode in a conventional UMTS communication system.

3 is a diagram illustrating an internal structure of a receiver of a general UMTS communication system.

4 is a graph illustrating the reception power of a received signal according to an operation mode of an AGC in a receiver of a general UMTS communication system.

5 is a diagram schematically illustrating an operation mode transition of an AGC in a receiver of a general UMTS communication system.

6 is a diagram schematically illustrating an operation mode transition of an AGC in a receiver of a UMTS communication system according to an embodiment of the present invention.

7 is a diagram illustrating an internal structure of an AGC control device for performing a function in an embodiment of the present invention.

FIG. 8 is a diagram schematically showing a gain constant control operation of the gain step controller 717 when E <F while using a single frame method.

일 경우의 이득 스텝 제어기(717)의 이득 상수 제어 동작을 개략적으로 도시한 도면9 uses a single frame scheme,

A diagram schematically showing a gain constant control operation of the gain step controller 717 in one case

10 is a diagram schematically showing a gain constant control operation of the gain step controller 717 in the case of using the dual frame method.

FIG. 11 is a graph illustrating variation of received power of a received signal when controlling a gain constant in a compressed mode (tracking gain constant: 32, capture gain constant: 128) according to an embodiment of the present invention.

12 is a graph illustrating a change in received power of a received signal when controlling a gain constant in a compressed mode according to an embodiment of the present invention (tracking gain constant: 4, capture gain constant: 128)

The present invention relates to an apparatus and method for controlling an automatic gain controller in an asynchronous mobile communication system, and more particularly, to an apparatus and method for controlling the automatic gain controller in accordance with a compression mode of the asynchronous mobile communication system.

The UMTS (Universal Mobile Terrestrial System, hereinafter referred to as UMTS) communication system, which is a next generation asynchronous mobile communication system, supports a compressed mode (hereinafter, referred to as a `` compressed mode ''). The compressed mode will now be described.

In the compressed mode, an arbitrary user terminal (UE) (hereinafter referred to as 'UE') is a handover between different frequencies, that is, an inter-frequency handover (hereinafter referred to as 'inter FR HO'), or different. This indicates a mode that provides a measurement interval required for performing HO between radio access methods, that is, inter-radio access technology handover (hereinafter referred to as 'inter RAT HO').

Next, a description will be given of the handover operation of the UE.

First, a UE receives a first common pilot channel (PCPICH) signal of receivable cells, that is, a serving cell and neighbor cells. Receive and measure the received field strength of the PCPICH signals received from the cells. The received electric field strength of the measured PCPICH signal is reported to a radio network controller (RNC: hereinafter referred to as 'RNC'). Then, the RNC determines the handover state of the UE based on the received electric field strength of the PCPICH signal reported from the UE, that is, (1) whether the UE should perform handover, or (2) when the UE performs handover. Which of the cells is determined to be handed over. As a result, in order for the UE to perform the handover, an operation of measuring PCPICH signals of neighbor cells for the UE is necessary.

As described above, in order for the UE to perform handover, an operation of measuring a PCPICH signal from neighboring cells as well as a serving cell is essential. The UE uses a frequency of use and a radio access between the cell to which the UE currently belongs. Problems arise when the methods are different. That is, when the neighboring cells use a different frequency than the cell to which the UE currently belongs or use a different radio access scheme, the UE uses a frequency or radio access of a transceiver to measure the PCPICH signal for the neighboring cells. The method must be changed to correspond to the neighbor cells. For example, any UE A is communicating through a UMTS Terrestrial Radio Access Network (UTRAN) system in a 2000 MHz band (hereinafter referred to as 'F_1'), and will be referred to as an 800 MHz band (hereinafter referred to as 'F_2'). In order to perform inter FR / inter RAT HO with a Global System for Mobile communication (GSM) system, the UE A temporarily suspends communication set to the F_1, and adjusts the UE A's own transceiver to F_2. After that, the signal measurement for the F_2 is performed. Then, afterwards, the transceiver must be adjusted to F_1 to resume communication through the UTRAN system. As a result, the compressed mode is fixed to the UE and the network so that the UE and the network can perform the necessary signal measurement by switching to a different frequency or different radio access method than the frequency and radio access method used in the currently connected cell as described above. Indicates a mode for stopping the period communication.

Next, a transmission structure according to the compressed mode will be described with reference to FIG. 1.

1 is a diagram schematically illustrating a transmission structure according to a compressed mode in a conventional UMTS communication system.

Referring to FIG. 1, first, the compressed mode is composed of a series of different transmission gap patterns (TGP: Transmission GP pattern, hereinafter referred to as 'TGP'), and the TGPs are transmitted with a transmission gap pattern sequence (TGPS). Gap Pattern Sequence, hereinafter referred to as 'TGPS'), which illustrates an arbitrary TGPS. One TGPS is repeated by TGP1 and TGP2 by the number of transmission gap pattern repetition counters (TGPRC), and different TGPSs have different TGP1 and TGP2. Here, the TGPRC represents the number of repetitions of the TGP. On the other hand, the TGPS is delivered from the upper layer to each base station and the UE, the information delivered from the upper layer is as follows.

(1) TGPS consists of TGPRC TGP1 and TGP2.

(2) The arbitrary TGP is composed of a transmission gap (TG) (hereinafter, referred to as 'TG') TG1 and TG2, and the UE performs inter frequency measurement in the TG1 and TG2.

(3) The starting point of the TG1 is calculated from the TGCFN and the transmission gap starting slot number (TGSN: hereinafter referred to as 'TGSN'). That is, the starting point of the TG1 is a TGSN time slot of a transmission gap connection frame number (TGCFN) (hereinafter, referred to as 'TGCFN'). As a result, the TGCFN represents a radio frame number at which the corresponding TGPS starts, and the TGSN represents a slot number of the TGCFN at which the first TG starts.

(4) The starting point of the TG2 is defined as a transmission gap distance (TGD: hereinafter referred to as 'TGD'). That is, the starting point of TG2 is the TGD th time slot from the starting point of TG1.

(5) The size of TG1 is TGL1 timeslots.

(6) The size of TG2 is TGL2 timeslots.

(7) The total size of TGP1 is TGPL1 radio frames.

(8) The total size of TGP2 is TGPL2 radio frames.

The information as described above (1) to (8) is summarized as follows.

Any TGPS is identified by a Transmission Gap Pattern Sequence Identifier (TGPSI), and information constituting the TGPS includes information about TGP1 and TGP2. Information about the TGPL1, TG1, TG2, TGD, and information about TGP2 is TGPL2, TG1, TG2, TGD. Each of the above information is mutually independent values, and information to be transmitted to the base station and the UE in advance from the upper layer before starting the compressed mode. Here, the TGPSI indicates an identifier indicating any one of a plurality of TGPS. The information constituting the TGPS includes TGPRS, TGCFN, TGSN, etc. in addition to the above information, and the information is applied to both TGP1 and TGP2, and is transmitted to the base station and the UE just before starting the compressed mode.

In addition, the radio frame is a unit indicating a transmission time in the UMTS communication system, one radio frame is composed of 15 time slots and has a length of 10msec. The timeslot consists of 2560 chips with a length of 0.667 msec. From the moment a dedicated physical channel (DPCH: hereinafter referred to as DPCH) is configured between the UE and the RNC, a connection frame number (CFN: hereinafter referred to as "CFN") is sequentially Increases by 1. That is, if a DPCH configured as a dedicated channel (DCH: Dedicated CHannel, hereinafter referred to as 'DCH') is configured between a UE and an RNC in an arbitrary radio frame, each time one radio frame elapses from the time point at which the DPCH is configured, CFN is increased by one. The RNC, the UE, and the base station maintain the same CFN for each UE. As described above, when the RNC delivers information on performing the compressed mode to the base station and the UE, the base station and the UE stop transmitting and receiving for each TG according to the information on performing the compressed mode received from the RNC, and the UE performs inter frequency measurement. Will be performed.

On the other hand, in order to blank the time slots corresponding to the TGL, a transmission interval corresponding to the TGL should be reduced. There are three ways to reduce the transmission interval as follows.

(1) compressed mode by puncturing

(2) compressed mode by spreading factor by 2

The spreading coefficient method is a method of reducing the transmission interval by reducing the spreading coefficient to 1/2.

(3) compressed mode by higher layer scheduling

The higher layer scheduling method is a method of reducing the transmission interval during actual data transmission by performing scheduling in advance before transferring data from the upper layer to the physical layer.

Except in the case of using the higher layer scheduling scheme among the three schemes, that is, when the puncturing scheme and the spreading coefficient scheme are used, the data to be transmitted by the transmitter is reduced from the original transmission interval, that is, the TGL. All transmissions must be transmitted in the transmission interval reduced by time slots. Therefore, in order to transmit all data in the reduced transmission interval, a separate power compensation operation is required. For this, the base station and the UE perform outer loop power control while performing power compensation according to the compressed mode. Must be performed simultaneously.

The minimum unit of the outer loop power control is a transmission time interval (TTI), and the transmitter, that is, the base station, to compensate for the TG while not performing inner loop power control during the TG. While performing the compressed mode, the DPCH signal is transmitted at a transmission power added by a preset offset compared to a transmission power for transmitting a general DPCH signal. Accordingly, when performing the outer loop power control, the receiver must determine a target signal to interference ratio (SIR) in consideration of this. Here, the target SIR is determined as shown in Equation 1 below.

는 i번째 프레임의 타겟(target) SIR을 나타내며,

는 i번째 프레임의 송신 전력 변화량을 나타낸다. In Equation 1, i represents a frame index,

Represents the target SIR of the i-th frame,

Denotes an amount of change in transmit power of the i-th frame.

In the interval in which the compressed mode is performed, the target SIR is updated every frame unit, and the transmitter transmits a signal with the transmission power compensated according to the compressed mode. The receiver also updates the target SIR to reflect the offset. Here, the transmission power that the transmitter increases or decreases to perform the compressed mode is calculated as in Equation 2 below.

과

은 상기 compressed mode 수행에 따른 천공 등의 동작으로 인해 감소한 송신 전력을 보상하기 위한 오프셋을 나 타낸다. 여기서, 상기 오프셋들

과

은 하기 수학식 3 및 수학식 4와 같이 계산된다.In Equation 2, n denotes all transport channels (TrCH: Transport Channel, hereinafter 'TrCH') of a code composite transport channel (CCTrCH). Indicates the number of different TTI lengths of the TTIs present in the

and

Denotes an offset for compensating for the reduced transmission power due to the puncturing operation of the compressed mode. Where the offsets

and

Is calculated as in Equations 3 and 4 below.

DeltaSIR1, DeltaSIR2, DeltaSIRafter1 and Equations 3 and 4 above. DeltaSIRafter2 is parameters received from a higher layer, and includes DeltaSIR1, DeltaSIR2, DeltaSIRafter1, and. DeltaSIRafter2 has a value of 0 to 3 [dB], respectively, when it has a 0.1 [dB] step size.

은 상기 compressed mode를 수행하는 방식에 상응하게, 즉 상기 compressed mode를 수행함에 있어 전송 구간을 줄이기 위한 방식에 상응하게 결정되는 값으로서 일 예로 하기 수학식 5와 같이 결정된다. Meanwhile, in Equation 2

Is a value determined corresponding to the method of performing the compressed mode, that is, corresponding to the method of reducing the transmission interval in performing the compressed mode, for example.

In Equation 5, Fi represents the number of frames per TTI of the current TrCH, and TGLi represents the number of time slots corresponding to the length of TGs present in Fi frames of TTI of the current TrCH.

를 각 compressed mode 패턴 별로 계산한 후 상기 compressed mode 패턴별로 계산한

들을 가산하여 생성한다. 그러면 여기서 도 2a 내지 도 2c를 참조하여 compressed mode 수행에 따른 오프셋 적용 동작에 대해서 설명하기로 한다.On the other hand, if there are multiple compressed mode frames at the same time

Calculated for each compressed mode pattern and then calculated for each compressed mode pattern

To add them. Next, the offset applying operation according to the compressed mode is described with reference to FIGS. 2A to 2C.

2A to 2C schematically illustrate an operation of applying an offset to transmission power when performing a compressed mode in a typical UMTS communication system.

이 DeltaSIR1,

이 0로 적용되고, 두 번째 프레임에는

이 DeltaSIRafter1고,

이 DeltaSIR2로 적용되고, 세 번째 프레임에는

이 0,

이 DeltaSIRafter2로 적용된 경우의 오프셋 적용 동작이 도시되어 있다. 또한, 상기 도 2c에는 첫 번째 프레임에는

이 DeltaSIR1,

이 DeltaSIR2로 적용되고, 두 번째 프레임에는

이 DeltaSIRafter1,

이 DeltaSIRafter2로 적용되고, 세 번째 프레임에는

이 0,

이 0으로 적용된 경우의 오프셋 적용 동작이 도시되어 있다.2A and 2B, the first frame

Is DeltaSIR1,

Is applied to 0, the second frame

Is DeltaSIRafter1,

Is applied to DeltaSIR2, and in the third frame

0,

The offset application operation when this DeltaSIRafter2 is applied is shown. Also, in FIG. 2C, the first frame

Is DeltaSIR1,

Is applied to DeltaSIR2 and in the second frame

Is DeltaSIRafter1,

Is applied to DeltaSIRafter2, and in the third frame

0,

The offset application operation when this is applied with 0 is shown.

Next, referring to FIG. 3, an operation of an automatic gain controller (AGC) will be described when performing a compressed mode in a general UMTS communication system.

3 is a diagram illustrating an internal structure of a receiver of a general UMTS communication system.

Referring to FIG. 3, the automatic gain controller includes a duplexer 311, a low noise amplifier (LNA) 313, and an automatic gain controller 320. And an analog-to-digital converter (A / D) 327, a demodulator 329, a power detector 331, a multiplier 333, cumulative An accelerator 335, a pulse duration modulation (PDM) converter 337, and a serial interface 339. Here, the mobile gain control unit 320 includes an LNA 321, a multiplier 323, and an AGC 325.

First, when a signal is received, the received signal is transferred to the duplexer 311, and the duplexer 311 duplexes the received signal and outputs the received signal to the LNA 313. The LNA 313 low noise amplifies the signal output from the duplexer 311 at a preset amplification rate and outputs the low noise amplification unit to the LNA 321 of the low noise amplifier 320. The LNA 321 low-noise amplifies the signal output from the LNA 313 at a predetermined amplification rate and outputs the same to the multiplier 323. The multiplier 323 receives the signal output from the LNA 321, multiplies the signal with an analog carrier, and outputs the signal to the AGC 325.

The AGC 325 inputs the signal output from the multiplier 323 and outputs the signal output from the serial interface 339, that is, the signal output from the multiplier 323 corresponding to the AGC control signal. And output to the analog-to-digital converter 327. The analog-to-digital converter 327 inputs the signal output from the AGC 325, digitally converts it, and outputs the digital signal to the demodulator 329 and the power detector 331. The demodulator 329 demodulates the signal output from the analog-to-digital converter 327 in a demodulation scheme corresponding to the modulation scheme applied by the modulator of the transmitter.

In addition, the power detector 331 inputs the signal output from the analog-to-digital converter 327 to detect a sample power error of the received signal and outputs it to the multiplier 333. The multiplier 333 multiplies the signal output from the power detector 331 with a preset gain constant and outputs the multiplier 335 to the accumulator 335. The accumulator 335 accumulates the signal output from the multiplier 333 to generate an automatic gain control signal and outputs the signal to the PDM converter 337. Here, the accumulator 335 operates as a kind of loop filter, and the filtering band of the loop filter is different according to the gain constant value, and the AGC 325 corresponding to the output of the loop filter. Generate an automatic gain control signal for controlling the automatic gain control operation. The PDM converter 337 performs PDM conversion on the signal output from the accumulator 335 and outputs the signal to the serial interface 339. The serial interface 339 feeds back the signal output from the PDM converter 337 to the AGC 325 so that the AGC 325 performs automatic gain control in accordance with the automatic gain control signal.

Next, an operation of the power detector 331 and the accumulator 335 for generating the automatic gain control signal will be described in detail.

First, the power detector 331 obtains an absolute value of a received sample, accumulates the absolute value in a predetermined set interval, and generates a standard error value corresponding to the value. That is, when the received power value calculated by the power detector 331 is equal to a received power value that the receiver wants to receive, that is, a target received power value, the power detector 331 may adjust the standard error value. Generate 0, and generate the standard error value as a positive value if the calculated received power value exceeds the target received power value; and if the calculated received power value is less than the target received power value, Generate a standard error value as a negative value.

A signal output from the power detector 331, that is, a standard mismatch value, is multiplied by the gain constant in the multiplier 333 and then output to the accumulator 335. As described above, the loop filtering band of the accumulator 335 is different according to the gain constant, and as a result, the performance of the AGC 325 tracking the change in the received power of the received signal is different according to the gain constant. The automatic gain control performance is different. Here, the gain constant is determined differently according to the state of the receiver. In a state such as initializing the receiver, that is, initializing a radio frequency interface, or changing a reception frequency when performing a compressed mode, Since the received power may change drastically, the gain constant is determined to be a relatively large value to control the AGC 325 to operate in an acquisition mode.

Next, an initial operation of AGC in a receiver of a general UMTS communication system will be described with reference to FIG. 4.

4 is a graph illustrating reception power of a received signal according to an operation mode of an AGC in a receiver of a general UMTS communication system.

Referring to FIG. 4, when the AGC performs an initialization operation, the AGC initially operates in a capture mode, that is, adjusts the received power to a relatively large step, thereby capturing the received power of the received signal and then tracking again. It operates in a tracking mode to adjust the received power to a relatively small step.

Next, the operation mode of the AGC in the receiver of the general UMTS communication system will be described with reference to FIG. 5.

5 is a diagram schematically illustrating an operation mode transition of an AGC in a receiver of a general UMTS communication system.

Referring to FIG. 5, when the compressed mode is performed as described above, the reception frequency band of the receiver is changed in the TG section so that the AGC gain adjustment before and after the frequency band is completely different. However, in the current UMTS communication system, there is no consideration of AGC control due to the transmission power compensation according to the compressed mode. Therefore, the AGC continuously operates in the tracking mode, and thus the automatic gain control of the received signal may fail. With AGC operating in tracking mode it is very difficult to correctly receive the transmit power compensated signal resulting from performing the compressed mode.

As described above, even if the TG is generated according to the compressed mode, the transmitter may compensate power for the frame corresponding to the TG since transmission or reception of actual data should not be stopped or data transmission / reception performance is deteriorated. Due to the power compensation, the receiver may increase or decrease the received power corresponding to 9 [dB], for example, from 2 to 3 [dB] when the receiver is small, and the reception power increase and decrease range is a general automatic gain control of the AGC of the receiver. The range of motion is difficult to track. In general, except for an initial operation process of performing an initialization operation according to power on, the AGC operates in a tracking mode instead of an acquisition mode, so that the AGC operates normally in accordance with the received power increase / decrease range. The time required is very long, and the reception performance of the receiver is degraded due to abnormal AGC operation.

As such, when the time required for correcting the received power is increased, the difference between the target received power and the actual received power becomes large during the time when the received power is correctly corrected, which may cause the following problems.

(1) Performance degradation due to increased quantization noise of ACG

(2) possibility of non-linear section operation due to AGC saturation potential

(3) If the TGSN is short, there is a possibility of entering the TG section before the reception power correction is successful.

In addition, the UMTS communication system supports not only the TG section but also operations according to a discontinuous transmission (DTX) section, and an AGC operation that may occur in the TG section in the DTX section. The problems may occur equally.

Accordingly, an object of the present invention is to provide an apparatus and method for controlling an automatic gain controller according to a compression mode of an asynchronous mobile communication system of the present invention.

Another object of the present invention is to provide an apparatus and method for controlling an automatic gain controller corresponding to a power compensation operation according to TG when performing a compression mode in a mobile communication system.

The apparatus of the present invention for achieving the above objects; An automatic gain controller control apparatus for a compression mode for performing a transmission blanking interval operation, which is a signal measurement interval according to a handover between base stations using different frequency bands, in accordance with an automatic gain control signal generated according to a predetermined control. An automatic gain controller for correcting a received power of a received signal, a power detector for generating a standard error which is a difference between the corrected received power and a target received power, a multiplier for multiplying the standard error and a gain constant generated according to a predetermined control; A accumulator for accumulating the signal output from the multiplier for a predetermined period and generating the automatic gain control signal, detecting a transmission blank section according to the compression mode, and detecting the transmission blank section at the start point and the end point of the transmission blank section. The gain constant such that the automatic gain controller operates in acquisition mode. It characterized in that it comprises a step gain controller for generating.

The method of the present invention for achieving the above objects; In the automatic gain controller control method according to the compression mode to perform the transmission blank interval operation, which is a signal measurement interval according to the handover between the base stations using different frequency bands, corresponding to the automatic gain control signal generated according to a predetermined control Correcting a received power of a received signal, generating a standard error that is a difference between the corrected received power and a target received power, multiplying a gain constant generated according to the standard error and a predetermined control, and Accumulating a signal multiplied by an error and a gain constant for a predetermined period and generating the automatic gain control signal; detecting a transmission blank section according to the compression mode; and detecting the transmission blank section at the start point and the end point of the transmission blank section. Generating the gain constant such that the automatic gain controller operates in a capture mode. And the information characterized by the capsule hamham.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that in the following description, only parts necessary for understanding the operation according to the present invention will be described, and descriptions of other parts will be omitted so as not to distract from the gist of the present invention.

In the present invention, when a receiver performs a compressed mode (hereinafter, referred to as a "compressed mode") operation in a UMTS (Universal Mobile Terrestrial System) communication system, which is an asynchronous mobile communication system, When the transmission power of the transmitter changes as the compressed mode is performed, an operation mode of an automatic gain controller (AGC) will be referred to as an "AGC" in tracking mode and acquisition mode. The present invention proposes an apparatus and method for controlling the power to be changed to R 로) so as to accurately and quickly perform reception power correction of a received signal. Hereinafter, for convenience of description, the AGC operation according to the discontinuous transmission (DTX: discontinuous transmission, hereinafter referred to as DTX) operation will be described only for the AGC operation according to the compressed mode. Of course, the same can be applied to the operation.

6 is a diagram schematically illustrating an operation mode transition of an AGC in a receiver of a UMTS communication system according to an embodiment of the present invention.

Referring to FIG. 6, the AGC operates in the tracking mode and starts when a transmission gap (TG: hereinafter referred to as 'TG') starts when the compressed mode is performed, that is, a transmission gap starting slot number ( At the time corresponding to TGSN: Transmission Gap Starting Slot Number (hereinafter, referred to as 'TGSN'), it operates in a capture mode. On the contrary, when the compressed mode operation is terminated while operating in the compressed mode, the controller also controls to operate in the capture mode. In this case, when the operation mode of the receiver is changed from the normal operation mode to the compressed mode, and when the AGC is controlled to operate in the capture mode when the compressed mode is changed to the normal operation mode, the reception power correction of the received signal of the AGC is corrected. The time can be shortened to enable normal signal reception operation.

However, as described with reference to FIG. 6, in order to change the operation mode of the AGC, an automatic gain control signal for controlling the operation of the AGC must be generated, and the operation of generating the automatic gain control signal will be described with reference to FIG. 7. Let's explain.

7 is a diagram showing the internal structure of the AGC control device for performing a function in an embodiment of the present invention.

Before describing FIG. 7, the AGC control apparatus proposed by the present invention is applied to the same receiver structure as that of the UMTS communication system described with reference to FIG. 3 of the prior art, except that the automatic gain control signal provided to the AGC is provided. It only differs in that it is generated differently depending on whether the compressed mode is performed. As described above, since the receiver structure of the UMTS communication system is assumed to be the same as the receiver structure of the UMTS communication system described with reference to FIG. 3, the detailed description thereof will be omitted here, and the AGC generating the automatic gain control signal provided to the AGC will be omitted. Only the control device will be described in detail.

Referring to FIG. 7, first, the AGC control apparatus includes a power detector 711, a multiplier 713, an accumulator 715, and a gain step controller 717. ) And a pulse duration modulation (PDM) converter 719.

First, a signal output from the analog-to-digital converter (A / D (A / D) converter) 327 of the receiver is input to the power detector 711 to detect a sample power error of the received signal. After that, it is output to the multiplier 713. The multiplier 713 multiplies the signal output from the power detector 711 with a preset gain constant and outputs the multiplier 715 to the accumulator 715. The accumulator 715 accumulates the signal output from the multiplier 713 to generate an automatic gain control signal and outputs the signal to the PDM converter 718. Here, the accumulator 715 operates as a kind of loop filter, and the filtering band of the loop filter is set according to the gain constant value. And generating an automatic gain control signal for the AGC 325 corresponding to the output of the loop filter. The PDM converter 719 PDM converts the signal output from the accumulator 715 and feeds it back to the AGC 325 so that the AGC 325 performs automatic gain control in accordance with the automatic gain control signal. .

The operation of the power detector 711 and the accumulator 715 for generating the automatic gain control signal will now be described in detail.

First, the power detector 711 obtains an absolute value of a received sample, accumulates the absolute value in a predetermined set interval, and generates a standard error value corresponding to the value. That is, when the received power value calculated by the power detector 711 is equal to a received power value that the receiver wants to receive, that is, a target received power value, the power detector 711 may adjust the standard error value. Generate 0, and generate the standard error value as a positive value if the calculated received power value exceeds the target received power value; and if the calculated received power value is less than the target received power value, Generate a standard error value as a negative value.

A signal output from the power detector 711, that is, a standard error value, is multiplied by the gain constant in the multiplier 713 and then output to the accumulator 715. As described above, the loop filtering band of the accumulator 715 is different according to the gain constant, and as a result, the performance of the AGC 325 tracking the change in the received power of the received signal is different according to the gain constant. The automatic gain control performance is different.

As described above, since the automatic gain control performance differs according to the gain constant, the present invention controls the gain constant as follows.

First, the initial time slot of the frame in which the compressed mode is started generates the gain constant so that the AGC can operate in acquisition mode.

Second, AGC operation in general TG interval is supported as it is.

Third, since the DTX section is also a section in which no actual signal reception exists, if there is a DTX section after the TG section or before the TG section, it is assumed that there is no signal reception during the TG section and the DTX section. To support AGC operation. That is, the gain constant is generated to be zero. Next, the operation of detecting the DTX section will be described below.

First, in order to detect the DTX interval, the following parameters must be considered.

(1) D: Number of bits of a transport format combination indicator (TFCI) field in one frame

(2) N _TFCI : Number of bits of TFCI field in one time slot

(3) N _first : number of timeslot where TG starts

(4) N _last : number of timeslot where TG ends

(5) E: The position of the first bit of the TFCI field starting to fill the DTX, that is, the number of bits of the TFXI field in the time slot (0 to N ^first -1) before TG starts in one frame (E = N _TFCI * N _first )

(6) F: Number of TFCI bits actually transmitted in one frame

)(

)

However, nA and nB represent a slot format of a downlink dedicated physical channel (DPCH: hereinafter referred to as 'DPCH'), and the DPCH slot format is an upper layer. In advance) to the physical layer (physical layer).

In the compressed mode, TG is determined by two methods, a single frame method and a double frame method, and there are two DTX interval insertion methods in the single frame method. There is one DTX interval insertion method. Here, the AGC control device, i.e., the gain step controller 717, must know in advance how the receiver currently determines the TG and inserts the DTX.

First, the gain step controller 717 is based on the N _TFCI , N _first and N _last and the transmission gap length (TGL: Transmission Gap Length, hereinafter referred to as 'TGL') based on the parameters E and D Calculate the value of. Here, the slot format of the UMTS communication system is shown in Table 1 below.

First, when the receiver determines the TG using the single frame method in the compressed mode, there are two DTX insertion methods. When the TG is determined using the dual frame method, there is one DTX insertion method. There are three ways to control the gain constant to operate the AGC in acquisition mode.

First, a gain constant control operation of the gain step controller 717 in the case of E <F while using a single frame method will be described with reference to FIG. 8.

8 is a diagram schematically illustrating a gain constant control operation of the gain step controller 717 when E <F while using a single frame method.

Referring to FIG. 8, first, the gain step controller 717 has to control the operation mode of the AGC 325 to the acquisition mode at the point indicated by the acquisition arrow, so that the gain constant is changed to the AGC 325. Can operate in capture mode, and the tracking mode must control the operating mode of AGC 325 in the tracking mode, so that the gain constant of the AGC 325 operates in tracking mode. In this case, the gain constant of the AGC 325 is generated as 0 when the hold is made due to the DTX interval. The reason for generating the gain constant as 0 is to hold the operation of the AGC 325.

In FIG. 8, F, E, and D of N _TFCI = 16, N _first = 5, N _last = 8, and TGL = 4 (when the slot format is 12A in a UMTS communication system) are calculated. E = N _first N _TFCI = 80 (E <F), D = N _TFCI * (15-TGL) = 176.

인 경우의 상기 이득 스텝 제어기(717)의 이득 상수 제어 동작을 도 9를 참조하여 설명하기로 한다.Secondly, using the single frame method

In this case, the gain constant control operation of the gain step controller 717 will be described with reference to FIG. 9.

일 경우의 이득 스텝 제어기(717)의 이득 상수 제어 동작을 개략적으로 도시한 도면이다.9 is a single frame method,

FIG. 1 schematically illustrates a gain constant control operation of the gain step controller 717 in one case.

Referring to FIG. 9, first, the gain step controller 717 must control the operation mode of the AGC 325 to the acquisition mode at the point indicated by the acquisition arrow, so that the gain constant is set to the AGC 325. Can operate in capture mode, and the tracking mode must control the operating mode of AGC 325 in the tracking mode, so that the gain constant of the AGC 325 operates in tracking mode. In this case, the gain constant of the AGC 325 is generated as 0 when it is held by the DTX interval.

In FIG. 9, E of N _TFCI = 4, N _first = 9, N _last = 13, and TGL = 5 (when the slot format is 11A in a UMTS communication system) is calculated, and thus F = 32, E = N _first N _TFCI = 36 (E> F). Here, F represents the number of bits of TFCI transmitted in one frame, and in the UMTS communication system, F has either 32 or 128.

Third, a gain constant control operation of the gain step controller 717 in the case of using the dual frame method will be described with reference to FIG.

10 is a diagram schematically illustrating a gain constant control operation of the gain step controller 717 in the case of using the dual frame method.

Referring to FIG. 10, first, the gain step controller 717 must control the operation mode of the AGC 325 to the acquisition mode at the point indicated by the acquisition arrow, so that the gain constant is changed to the AGC 325. Can operate in capture mode, and the tracking mode must control the operating mode of AGC 325 in the tracking mode, so that the gain constant of the AGC 325 operates in tracking mode. In this case, the gain constant of the AGC 325 is generated as 0 when it is held by the DTX interval.

In FIG. 10, F, E, and D of N _TFCI = 16, N _last = 4, and TGL = 10 (when the slot format is 12A in a UMTS communication system) are calculated, and thus F = 128, E = 0, D. = (14-N _last ) * N _TFCI = 160.

Next, a change in reception power of a received signal input to the receiver in the compressed mode will be described with reference to FIGS. 11 and 12.

FIG. 11 is a graph illustrating variation of received power of a received signal when controlling a gain constant in a compressed mode (tracking gain constant: 32, capture gain constant: 128) according to an embodiment of the present invention.

In FIG. 11, the red graph is a graph illustrating a change in reception power of a received signal through AGC when a gain constant is controlled according to generation of TG and DTX intervals in a compressed mode according to an embodiment of the present invention. As a graph showing the variation of the received power of the received signal through the AGC, it can be seen that the performance difference is large. That is, when the gain constant is controlled according to the generation of the TG and DTX intervals in the compressed mode as in the embodiment of the present invention, the reception power similar to the target reception power can be maintained even in the TG interval and the DTX interval, resulting in excellent performance.

12 is a graph illustrating a change in received power of a received signal when controlling a gain constant in a compressed mode (tracking gain constant: 4, capture gain constant: 128) according to an embodiment of the present invention.

In FIG. 12, the red graph is a graph illustrating a change in reception power of a received signal through AGC when a gain constant is controlled according to generation of TG and DTX intervals in a compressed mode according to an embodiment of the present invention, and a blue graph is a general case. As a graph showing the variation of the received power of the received signal through the AGC, it can be seen that the performance difference is large. That is, when the gain constant is controlled according to the generation of the TG and DTX intervals in the compressed mode as in the embodiment of the present invention, the reception power similar to the target reception power can be maintained even in the TG interval and the DTX interval, resulting in excellent performance.

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, the present invention allows the receiver of the UMTS communication system to adjust the received power of the received signal according to the compressed mode by changing the operation mode of the AGC to the capture mode, so as to accurately and quickly perform the received power correction of the received signal. do.

Claims (18)

In the automatic gain controller control apparatus according to the compression mode to perform the transmission blank interval operation, which is a signal measurement interval according to the handover between the base stations using different frequency bands, An automatic gain controller for correcting the received power of the received signal in correspondence with the automatic gain control signal; A power detector for generating a standard error that is a difference between the corrected received power and a target received power; A multiplier for multiplying the standard error by a gain constant; An accumulator for accumulating the signal output from the multiplier for a predetermined period and generating the automatic gain control signal; A gain step controller for detecting a transmission blank section according to the compression mode and controlling the gain constant such that the automatic gain controller operates in a capture mode at a start time and an end time of the transmission blank section; The device. The method of claim 1, And the gain step controller generates the gain constant such that the automatic gain controller operates in a tracking mode at a time other than a start time and an end time of the transmission blank interval. The method of claim 1, When the gain step controller detects that not only the transmission blank section but also the discrete transmission section exist when the compression mode is performed, the automatic gain controller at the start point and the end point of the section in which the transmission blank section and the discontinuous transmission section are added. And a gain step controller for generating said gain constant to operate in an acquisition mode. The method of claim 3, And the gain step controller generates the gain constant such that the automatic gain controller operates in a tracking mode at a time other than the start time and the end time point of the interval in which the transmission empty period and the discontinuous transmission period are added. The method of claim 4, wherein And the gain step controller generates the gain constant as zero in the discontinuous transmission period so as to control the automatic gain controller to maintain the previous operation. The method of claim 5, The gain step controller is configured to control the Beast of a Transport Format Combination Indicator (TFCI) field in a time slot, a time slot number at the beginning of the transmission gap, and a time slot number at the end of the transmission gap. And detecting the discontinuous transmission interval corresponding to the number of time slots constituting the transmission gap. In the automatic gain controller control method according to the compression mode for performing the transmission blank interval operation, which is a signal measurement interval according to the handover between the base stations using different frequency bands, Correcting the received power of the received signal corresponding to the automatic gain control signal; Generating a standard error which is a difference between the corrected received power and a target received power; Multiplying the standard error by a gain constant; Accumulating the signal obtained by multiplying the standard error and the gain constant for a predetermined period and generating the automatic gain control signal; Detecting a transmission blank interval according to the compression mode, and controlling the gain constant such that the automatic gain controller operates in a capture mode at a start time and an end time of the transmission blank period; . The method of claim 7, wherein After detecting the transmission blank period according to the compression mode execution, generating the gain constant such that the automatic gain controller operates in the tracking mode at a time other than the start time and the end time of the transmission blank period. Characterized in that the method. The method of claim 7, wherein When the compression mode is detected, the automatic gain controller operates in the acquisition mode at the start time and the end time of the interval in which the transmission empty interval and the discontinuous transmission interval are added. Generating the gain constant. The method of claim 9, After detecting that there is not only the transmission blank period but also the discontinuous transmission period, the automatic gain controller operates in the tracking mode at a time other than the start time and the end time of the interval where the transmission blank period and the discontinuous transmission period are added. Generating a gain constant. The method of claim 10, And after detecting that there is a discrete transmission section as well as the transmission empty section, generating the gain constant to 0 in the discrete transmission section to control the automatic gain controller to maintain the previous operation. Said method. The method of claim 11, The detecting of the discontinuous transmission interval may include: a beast of a transport format combination indicator (TFCI) field in a time slot, a time slot number at which the transmission space starts, and a time point at which the transmission space ends. And detecting the discontinuous transmission interval in correspondence with the timeslot number of and the number of timeslots constituting the transmission gap. The method of performing automatic gain control in a communication system is as follows: Performing automatic gain control in tracking mode when receiving a signal in a normal mode; And receiving a signal in a compression mode, and performing automatic gain control in an acquisition mode at the start of the compression mode. The method of claim 13, Auto gain control is performed by switching from tracking mode to acquisition mode at least one of the end of the compression mode, the start of the transmission gap in the compression mode, and the end of the transmission gap in the compression mode. Characterized in that the method. The method of claim 13, The method characterized in that the automatic gain control hold during the discontinuous transmission (DTX) interval. Devices that perform automatic gain control in telecommunication systems include: An automatic gain control unit controlling the gain of the received signal; A power detector for detecting power of a received signal; A gain constant generator which generates a gain constant using the output value of the power detector; When the signal is received in the normal mode, the gain constant is adjusted so that the automatic gain control is performed in the tracking mode, and when the signal is received in the compression mode, the acquisition mode at the start of the compression mode. And a controller for adjusting the gain constant so that automatic gain control is performed. The method of claim 16, The control unit switches to the capture mode from the capture mode to the capture mode at least one of the end of the compression mode, the start of the transmission gap in the compression mode, and the end of the transmission gap in the compression mode. And adjust the gain constant to perform the following. The method of claim 16, And the control unit adjusts the gain constant to hold the automatic gain control during a discontinuous transmission (DTX) period.

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