JP2012034367A - Wireless communication terminal and automatic gain control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wireless communication terminal and an automatic gain control method.SOLUTION: A wireless communication terminal comprises: automatic gain control means for performing an automatic gain control for an input signal received by the wireless communication terminal; gap control means for controlling the start and the end of a gap; gap operation specification means for specifying an operation to be performed at a next gap; and mode control means for setting a mode of the automatic gain control means at the next gap based on the specified operation.

Description

  The present invention relates to wireless communications, and more particularly to automatic gain control (AGC) in time division duplex (TDD) wireless communication systems.

  In the radio communication terminal, the amplitude and power of the received signal change dynamically and greatly due to the effect of attenuation of the radio channel (path loss, shadow fading, multipath fading, etc.) and the change of work load. Such signal quantization distortion due to a signal having a large dynamic range is generally solved by using an automatic gain control (AGC) technique. Assuming that the word length of an analog / digital converter (ADC) does not increase, a signal with a large dynamic range is automatically adjusted to a dynamic range suitable for the ADC word length to reduce quantization distortion. Another advantage of AGC technology is that the implementation cost is reduced, and a small ADC word length is used to provide sufficient quantization accuracy and subsequent baseband circuit implementation complexity. Reduced.

  In 3GPP (3rd Generation Partnership Project) LTE (Long Term Evolution) system, cell search including initial cell search, neighbor cell search, etc. is an important physical process. The adjacent cell search process of the same system further includes a cell search of the same frequency and a cell search of a different frequency. For cell search of different frequencies, the 3GPP 36.133 standard stipulates that one GAP (gap) (length is 6 ms) is divided in a certain period (every 40 ms or 80 ms) in a system. As shown in FIG. 1, in GAP, a serving cell does not transmit data to a terminal, but allows the terminal to perform cell search and cell measurement at different frequencies using this period.

  In the dialogue process between the radio communication terminal and the serving cell, the gain value of the radio communication terminal is adjusted to match the serving cell, but when the adjacent cell search and measurement of different frequencies is performed, the frequency is switched to the frequency occupied by the non-serving cell. there is a possibility. In this case, it is necessary to make a new adjustment in the wireless communication terminal so as to adapt to the characteristics of the cell signal having a different frequency.

In the cell search of different frequencies, there is a possibility that base stations between cells are asynchronous. That is, the terminal does not know the timing information of the cells of different frequencies. In the TD-LTE system, AGC may use the gain value derived from the uplink signal for the downlink signal, and may use the gain value corresponding to the uplink / downlink conversion interval for the downlink signal. As a result, the quantization error of the downstream signal is too large, or the clipping is excessive. Therefore, it is necessary to design the AGC algorithm in the GAP.
The following outlines the present invention for a basic understanding of some embodiments of the present invention. It should be understood that this summary is a description of one aspect of the invention. This does not identify the invention and does not limit the scope of the invention.

  According to one aspect of the present invention, a wireless communication terminal, automatic gain control means for performing automatic gain control on a received signal of the wireless communication terminal, gap control means for controlling start and end of a gap, and There is provided a wireless terminal comprising: a gap operation specifying unit that specifies an operation to be performed in the gap; and a mode control unit that sets a mode of an automatic gain control unit in the next gap based on the specified operation.

  According to another aspect of the present invention, there is provided an automatic gain control method used in a radio communication terminal, the step of specifying an operation to be performed in the next gap, and the automatic gain control in the next gap based on the specified operation A method is provided that includes setting a mode of operation and performing an automatic gain control operation on a received signal of a wireless communication terminal according to a set automatic gain control mode.

  The disclosed wireless terminal is designed for the characteristics of GAP in a wireless communication system, and the accuracy of the quantized signal in each operation state is ensured in the GAP in the wireless communication terminal.

It is a schematic diagram which shows GAP of a LTE system. It is a figure which shows the frame structure of a TD-LTE system. It is a figure which shows the position of the reference signal in the frame structure of a TD-LTE system. It is a figure which shows the radio | wireless communication terminal of one Example by this invention. It is a figure which shows the automatic gain control means in the radio | wireless communication terminal of one Example by this invention. It is a figure which shows the gain generator in the radio | wireless communication terminal of one Example by this invention. It is a figure which shows the realization method of the high speed mode of one Example by this invention. It is a figure which shows another realization method of the high-speed mode of one Example by this invention. It is a figure which shows operation of the automatic gain control in the low speed mode of one Example by this invention. It is a figure which shows the automatic gain control method used for the radio | wireless communication terminal of one Example by this invention.

  The above and other objects, features and advantages of the present invention can be more easily understood with reference to the following description of the embodiments of the present invention based on the drawings. The elements in the drawings are only for illustrating the principles of the invention. In the drawings, the same or similar technical features or elements are denoted by the same or similar drawing symbols.

  Embodiments of the present invention will be described below with reference to the drawings. Elements and features described in one drawing or embodiment of the invention may be combined with elements or features shown in one or more other drawings or embodiments. For the sake of clarity, it should be noted that in the drawings and specification, the present invention is not related to the present invention, and the description and description of elements or processes known to those skilled in the art may be omitted.

  Below, a 3GPP LTE (long-term evolution) TDD system (TD-LTE system) is illustrated as an example of a TDD system. However, it should be noted that the present invention is not limited to the TD-LTE system and may be applied to similar systems.

  FIG. 2 is a schematic diagram showing a frame structure of the TD-LTE system. In the TD-LTE system, three types of subframe structures are included, that is, an uplink subframe, a downlink subframe, and a special subframe. In FIG. 1, subframes # 0, # 3, and # 4 are downlink subframes, subframe # 2 is an uplink subframe, and subframe # 1 is a special subframe. In the following, the downlink subframe is indicated by “D”, the uplink subframe is indicated by “U”, and the special subframe is indicated by “S”. “X” indicates that the type of the current subframe is unknown. Each subframe includes two slots having a length of 0.5 ms. The special subframe includes DwPTS, GP, and UpPTS. As shown in FIG. 1, the primary synchronization symbol (Primary synchronization symbol, PSS) is located in the third symbol of DwPTS, and the secondary synchronization symbol (Secondary synchronization symbol, SSS) is in the first subframe (SF # 0) is located in the last symbol. In the cell search, frame timing and cell ID are acquired by detecting these two synchronization symbols.

Table 1 shows some frame arrangements in the TD-LTE system.

FIG. 3 shows the position of the reference signal in the frame structure of the TD-LTE system. In FIG. 3, the position indicated by R ₀ is the position of the reference signal for port ₀ , and the hatched position is the position of the reference signal for port 1. As shown in FIG. 3, the reference signal is located at the # 0 and # 4 symbols in the slot. In the downstream signal, the reference signal is transmitted regardless of the presence or absence of data transmission.

  FIG. 4 shows a wireless communication terminal 400 according to an embodiment of the present invention.

  The wireless communication terminal 400 includes gap control means 402, gap operation specifying means 404, mode control means 406, and automatic gain control means 408. Automatic gain control means 408 performs automatic gain control on the received signal of wireless communication terminal 400. The gap control unit 402 controls the start and end of the gap. For example, the gap control unit 402 controls the start and end of the gap by receiving a signal related to the GAP from the base station, and the local frequency control unit (not shown) has a predetermined different frequency after the start of the GAP. It can be notified to adjust to the frequency point and adjust back to the frequency point of the serving base station before the GAP process ends. In addition, after the necessary adjustment time has elapsed for the VCO, the neighboring cell search means (not shown), the channel measurement means (not shown), etc. are notified to start, and are necessary for the VCO to be adjusted back. Before the time elapses, the corresponding means are turned off. The gap operation specifying unit 404 specifies an operation to be performed in the next gap. The mode control means 406 sets the mode of the automatic gain control means 408 in the next gap based on the specified operation. In one example, the automatic gain control means has a gain value adjustment period smaller than or equal to the length of one subframe in the high speed mode, but has a gain value adjustment period of one subframe in the low speed mode. Greater than the length of

  In one example, the modes of the automatic gain control means include a high speed mode, a low speed mode, and a stop mode. In the automatic gain control means 408, the gain value adjustment cycle in the high speed mode is smaller than the gain value adjustment cycle in the low speed mode. The automatic gain control means 408 does not perform automatic gain control in the stop mode.

  The wireless communication terminal synchronizes the time and frequency of adjacent base stations of different frequencies, detects the ID of the cell of the different frequency, and more accurately synchronizes time and frequency based on the synchronization by the adjacent cell search. The cell search of different frequencies is performed by the step of tracking and the step of measuring the signal quality and signal interference level of neighboring cells of different frequencies. The above steps and the elements that realize these steps can be appropriately implemented by those skilled in the art, and will not be described in detail here.

  In one example, the operations performed in the next gap specified by the gap operation specifying means 404 are, for example, a gain value initial convergence operation, a primary synchronization symbol detection operation, a secondary synchronization symbol detection operation, and a gain value reconvergence operation. And one or more of a channel measurement operation and a sleep operation. The gain value initial convergence operation can be used to perform the convergence of the gain value in the GAP returned from the very first GAP or the sleep mode (at this time, the wireless communication system has not acquired the frame timing). The primary synchronization symbol detection operation can be used to detect a primary synchronization symbol. The secondary synchronization symbol detection operation can be used to detect a secondary synchronization symbol. The gain value reconvergence operation can be used to further converge and stabilize the gain value after the wireless communication terminal detects the secondary synchronization symbol. The channel measurement operation can be used to measure the signal quality and signal interference level of neighboring cells of different frequencies. The sleep operation can be executed after the channel measurement is completed or after the cell search is temporarily failed, and at this time, the operation related to the cell search of the different frequency is not performed.

  The mode control unit 406 sets the mode of the automatic gain control unit 408 in the next gap to the high-speed mode when the operation performed in the next gap is the gain value initial convergence operation, the primary synchronization symbol detection operation, or the secondary synchronization symbol detection operation. When the operation performed in the next gap is a gain value reconvergence operation or a channel measurement operation, the mode of the automatic gain control means in the next gap is set to the low speed mode, and the operation performed in the next gap is a sleep mode. In the case of operation, the mode of the automatic gain control means 408 in the next gap is set to the stop mode.

  The gap operation specifying unit 404 can specify an operation to be performed in the next gap according to a predetermined setting. For example, the gain value initial convergence operation is performed in the first to L1 GAPs, the primary synchronization symbol detection operation is performed in the next L2 GAPs, the secondary synchronization symbol detection operation is performed in the next L3 GAPs, and the next It is possible to preset the gain value initial convergence operation in L4 GAPs, the channel measurement operation in the next L5 GAPs, and the sleep operation in the next L6 GAPs. The gap operation specifying unit 404 may specify an operation to be performed in the next gap based on an execution situation regarding the step of cell search for different frequencies in the radio communication terminal 400. For example, the gap operation specifying unit 404 can communicate with an element (not shown) for secondary synchronization symbol detection of the wireless communication terminal, and when the element completes the secondary synchronization symbol detection, the gap operation specifying unit 404 It can be specified that the operation performed in the next gap is a gain value reconvergence operation.

  In the present embodiment, the mode controller 406 adjusts the automatic gain control unit 408 to a different mode based on the operation performed in the next gap specified by the gap operation specifying unit 404, thereby allowing the radio communication terminal 400 to change the gap. The accuracy of the required quantized signal in each operation state in is guaranteed.

  FIG. 5 shows an automatic gain control means 500 in the wireless communication terminal of one embodiment according to the present invention.

  The automatic gain control means 500 includes a gain generator 506 that generates a gain value, and a variable gain amplifier 502 that adjusts the amplitude of the received signal based on the gain value generated by the gain generator 506 and outputs the adjusted signal. And an analog / digital converter 504 for converting the signal output from the variable gain amplifier 502 into a digital signal.

  The gain generator 506 measures the power of the received signal (the signal that has passed through the ADC) in a certain time period, compares it with the reference power, generates a gain value according to a certain algorithm, and transmits it to the variable gain amplifier 502 Thus, the amplitude of the analog signal received in the next time zone can be adjusted.

  FIG. 6 shows a gain generator 600 in a wireless communication terminal according to an embodiment of the present invention.

  The gain generator 600 includes a power measurement module 602 that measures the power of the received signal, a power comparison module 604 that compares the measured power of the received signal with the target power and identifies a power adjustment amount, and the identified current And an average module 604 for weighted averaging the previous power adjustment amount and the previous power adjustment amount.

  Hereinafter, the operation of each module of the gain generator 600 will be described using more specific examples.

K_setは１より大きいか又は等しい整数である。 In one example, the power measurement module 602 measures the average power in N _measure sample intervals for the received signal r (i). The length of time T _meas corresponding to N _measure samples corresponds to the length of a symbol using Normal CP in the TDD-LTE system, and the length of 14 T _{meas is} the length of one subframe 1 ms. It becomes. The obtained average power is as follows.

K _set is an integer greater than or equal to 1.

選択的に、対数変換により、

が得られる。 Although the average power is adopted as a measure of signal strength as described above, the present invention is not limited to this, and the average amplitude may be adopted as a measure of signal strength.
Next, the maximum value is obtained from the K _set measured powers.

Optionally, by log transformation,

Is obtained.

In the above description, the maximum value of the K _set measured powers is adopted as the measured power, but the present invention is not limited to this, and the average value of the K _set measured powers is determined as the measured power. May be adopted.

The power comparison module 604 identifies the power adjustment amount by comparing the measured power of the received signal with the target power. The target power can be specified from the difference between the maximum quantized power of the analog / digital converter and a margin value (Headroom). The maximum quantization power of the analog / digital converter is specified by the word length of the ADC. Suppose that the ADC word length is N _bits and the margin value is P _HR [dB].

However, P _HR may be set based on different modes of different automatic gain control means, or may be set based on the degree to which the signal is clipped by the ADC.

Next, a difference ΔP between the target power and the measured power can be calculated.

The power difference ΔP (that is, the power adjustment amount) in the j-th measurement section may be expressed as follows.

The averaging means 606 can perform a weighted average of the current power adjustment amount and the previous several adjustment amounts by the following equation.

を仮定する。αは忘却因子であり、異なる自動利得制御手段のモードに対して、忘却因子は０＜＝α＜＝１である。 In addition,

Assuming α is a forgetting factor. For different modes of the automatic gain control means, the forgetting factor is 0 <= α <= 1.

As a result, the final gain value is updated as follows.

The operation of the automatic gain control means in different modes will be described below.
In one embodiment, the wireless communication terminal, in continuous GAP, gain value initial convergence operation (the operation is performed by the automatic gain control means), primary synchronization symbol detection operation, secondary synchronization symbol detection operation, The gain value reconvergence operation, the channel measurement operation, and the sleep operation are sequentially executed. When the wireless communication terminal performs the gain value initial convergence operation, the primary synchronization symbol detection operation, and the secondary synchronization symbol detection operation, the automatic gain control means is set to the high speed mode by the mode control means. When the wireless communication terminal performs a gain value reconvergence operation (the operation is performed by the automatic gain control unit) or a channel measurement operation, the automatic gain control unit is set to the low speed mode by the mode control unit. When the wireless communication terminal executes the sleep operation, the automatic gain control means is set to the stop mode by the mode control means.

1. High-speed mode According to the frame structure shown in Table 1, the subframe before the special subframe is always a downlink subframe. By adjusting the DwPTS in the subframe and the special subframe, the gain value is converged to a gain value suitable for the synchronization symbol.

FIG. 7 shows a kind of realization method of the high-speed mode of the embodiment according to the present invention. In FIG. 7, T _meas K _set is a measurement time, and T _apply calculates a gain value and then feeds back the gain value to the VGA. The VGA adjusts based on the gain value and stabilizes the gain value. This is the processing delay required until the time is determined by the device level. In general, T _apply is much smaller than T _{meas /} K _set and can be ignored.

After the start of the high-speed mode (for example, the GAP head shown in the figure), for example, after the terminal is started or returned from the sleep state, first, a measurement / adjustment (warm up) of the different frequency cell is performed. Adjust the received signal level until it is within the operating range of the ADC. The number of adjustments can be set based on the dynamic range of the ADC and the dynamic range of the received signal. For example, for a signal with a dynamic range of 72 dB with a 12-bit ADC, the gain value is adjusted 3-5 times in the initial stage to ensure convergence from a randomly set gain value to an available gain value. Is done. Next, the wireless communication terminal starts an adjacent cell search of a different frequency. The value of the forgetting factor α can be 1 to ensure that the AGC can track signal power fluctuations. That is, the weight of the previous power adjustment amount can be set to 0 in the averaging module. Also, in order to prevent the signal from being clipped as much as possible and to ensure that it has a reasonable dynamic range, the value of P _HR is set to 9 to 36 dB, and more preferably about 18 to 27 dB.

In the TD-LTE system, adjacent cells of different frequencies may be asynchronous cells. When synchronization information of neighboring cells of different frequencies is unknown, it is necessary to perform gain value adjustment as many times as possible using a downlink subframe before the special subframe. At this time, the smaller the K _set value, the better. However, in order to avoid measuring completely empty symbols, K is _set with reference to FIG. 3 in consideration of setting K _set not to be smaller than the maximum time-domain interval between reference signals. The value of _set can be 4-5. That is, the measurement period of the power measurement module is set to the interval of the maximum time domain of the reference signal in the received signal, or one symbol is longer than the interval of the maximum time domain of the reference signal in the received signal. As shown in FIG. 6, the measurement periods do not overlap each other, and the gain value adjustment period (G0, G1,...) Of the automatic gain control means is equal to the measurement period of the power measurement module. In one embodiment, the adjustment period of the gain value of the automatic gain control means may be larger than the measurement period of the power measurement module.

Further, it is possible to avoid the influence of the AGC by the upward and downward intervals GP, increasing the offset value of one margin value after having a P _HR constant. As a result, the target power is indicated as follows.

Here, P _offset > = 0, which is determined in proportion to clipping of the signal, and P _offset increases as more clipping is performed. For example, the offset value of the margin value can be obtained by using the overflow output mechanism of the ADC. Specifically, it is possible to calculate the ratio between the number of overflow samples and the total number of samples in the corresponding measurement section T _{meas ·} K _set in the high-speed mode. A fixed threshold method may be employed, and P _offset = 3 dB when the ratio value exceeds 10%, and P _offset = 6 dB when the ratio value exceeds 20%. If the ADC does not have an overflow output function, the ratio between the number of full-scale output samples and the total number of samples may be used instead.

FIG. 8 shows another method for realizing the high-speed mode of the embodiment according to the present invention. Compared with FIG. 7, the measurement periods (Measure) overlap each other, the adjustment period (G0, G1,...) Of the gain value of the automatic gain control means becomes smaller than the measurement period of the power measurement module, and the adjustment period is 1-2. Different T _meas . Also, T _apply in FIG. 7 is ignored. Compared to FIG. 7, the convergence speed of the gain value is faster in FIG.

  When the secondary synchronization symbol detection is completed, the cell search means detects timing information, a carrier frequency position, and a cell ID of a base station having a different frequency. As a result, the controller is triggered and further notifies the AGC means to stop the high speed mode and shift to the low speed mode.

  When shifting from the high speed mode to the low speed mode, the following two methods can be employed.

  1． In the last GAP in the high-speed mode, the AGC gain value when the GAP is completed is stored, the terminal adjusts back to the carrier frequency of the serving cell, and receives a signal using the AGC corresponding to the serving base station. From the next GAP, that is, the GAP at the start of the low-speed mode, the operation to operate the base station of the different frequency by using the stored gain corresponding to the base station of the different frequency is recovered.

  2． Stores the previous N update values in the fast mode in the GAP, where N is an integer greater than or equal to one. If the secondary synchronization symbol is successfully detected in the GAP, the high-speed mode stops at the GAP. Transition to low-speed mode at the next GAP. At this time, the AGC gain corresponding to the section where the peak value is detected corresponding to the secondary synchronization symbol is used as the gain of the GAP.

2． Low Speed Mode FIG. 9 shows the operation of automatic gain control in the low speed mode of the embodiment according to the present invention. In the low speed mode, the frame timing has already been acquired (detection of the primary synchronization symbol and detection of the secondary synchronization symbol have already been completed). At this time, AGC measures a low-speed AGC gain value in subframe 0 or subframe 5 based on the frame timing information. One gain value is used for each GAP, and the gain value (gain) generated in the previous GAP is used by the automatic gain control means of the next GAP (for example, a variable gain amplifier in the automatic gain control means). When the channel measurement operation is completed, the wireless communication terminal stores the AGC gain value corresponding to the adjacent base station having a different frequency. At the end of the GAP, the VCO is adjusted back to the serving base station carrier frequency and the signal is received using the serving base station AGC gain. When the next GAP arrives, the wireless communication terminal uses the stored adjacent base station gain of the different frequency.

In order to guarantee the stability of the gain value in the low speed mode, the value of the forgetting factor α is set to 0.1 to 0.5. That is, the ratio between the weight of the previous power adjustment amount and the weight of the current power adjustment amount in the average module is 1 to 9. K _set is 14, that is, the measurement period of the power measurement module is one subframe. The value of P _HR is 9-36 dB, preferably about 18-27 dB.

In one embodiment, the operation parameters in each mode of the automatic gain control means, such as the forgetting factor α, K _set , P _HR, etc. can be set by the mode control means. In another embodiment, the mode control means may set only the mode and / or the stage in the mode of the automatic gain control means, and parameters in each operation mode may be set in the automatic gain control means in advance. .

  FIG. 10 shows an automatic gain control method used in the radio communication terminal according to the embodiment of the present invention.

  In step 1002, an operation to be performed in the next gap is specified. In step 1004, the mode of the automatic gain control operation in the next gap is set based on the specified operation. In step 1006, an automatic gain control operation is performed on the received signal of the wireless communication terminal according to the set automatic gain control mode.

  In one example, the modes of the automatic gain control operation include a high speed mode, a low speed mode, and a stop mode. In the automatic gain control operation, the gain value adjustment cycle in the high speed mode is smaller than the gain value adjustment cycle in the low speed mode, and the automatic gain control operation is not performed in the stop mode.

  In one example, the automatic gain control operation is performed in a high-speed mode where the gain value adjustment period is smaller than or equal to the length of one subframe, but in the low-speed mode, the gain value adjustment period is one subframe. Greater than the length of

  In one example, the operation performed in the next gap is one of a gain value initial convergence operation, a primary synchronization symbol detection operation, a secondary synchronization symbol detection operation, a gain value reconvergence operation, a channel measurement operation, and a sleep operation. Including more than one. Setting the automatic gain control operation mode in the next gap means that if the operation performed in the next gap is a gain value initial convergence operation, a primary synchronization symbol detection operation, or a secondary synchronization symbol detection operation, If the automatic gain control operation mode is set to the high speed mode, and the operation performed at the next gap is a gain refocusing operation or a channel measurement operation, the automatic gain control operation mode at the next gap is set to Setting the low-speed mode includes setting the automatic gain control operation mode at the next gap to the stop mode when the operation performed at the next gap is the sleep operation.

  In one illustration, the automatic gain control operation includes using only one gain value for each of each gap in the slow mode. The gain value is generated in the previous gap.

  In one example, the automatic gain control operation generates a gain value, adjusts the amplitude of the received signal based on the gain value, and performs an analog / digital conversion on the adjusted signal to generate a digital signal. Including conversion to In one example, generating the gain value includes measuring the power of the received signal, identifying the power adjustment amount by comparing the measured power of the received signal and the target power, and Including a weighted average of the current power adjustment amount and the previous power adjustment amount.

  In one example, when the automatic gain control operation is in the high speed mode, the weight of the previous power adjustment amount is set to zero.

  In one example, the target power may be a difference between the maximum quantized power and a margin value. When the automatic gain control operation is in the high speed mode, the margin value is set to 9 to 36 dB, preferably 18 to 27 dB.

  In one example, the target power is obtained by subtracting the sum of the margin value and the margin offset value from the maximum quantized power. The offset value of the margin value increases as the proportion of the signal clipped in the analog / digital conversion increases. When the automatic gain control operation is in the high speed mode, the margin value is set to 9 to 36 dB, preferably 18 to 27 dB.

  In one example, when the automatic gain control operation is in the high speed mode, the measurement period in the measurement of the power of the received signal is the interval of the maximum time domain of the reference signal of the received signal or the reference of the received signal. The length of one symbol is set to be longer than the maximum time domain interval of the signal, the measurement periods do not overlap each other, and the adjustment period of the gain value of the automatic gain control operation is greater than or equal to the measurement period.

  In one example, when the automatic gain control operation is in the high-speed mode, the measurement period in the measurement of the power of the received signal is the interval of the maximum time domain of the reference signal of the received signal, or of the received signal The reference signal is set to be one symbol longer than the maximum time domain interval of the reference signal, the measurement periods overlap each other, and the gain value adjustment period of the previous automatic gain control operation is smaller than the measurement period.

  In one example, when the automatic gain control operation is in the low speed mode, the ratio between the weight of the previous power adjustment amount and the weight of the current power adjustment amount is 1 to 9.

  In one example, the target power is the difference between the maximum quantized power and the margin value. When the automatic gain control operation is in the low speed mode, the margin value is set to 9 to 36 dB, preferably 18 to 27 dB.

  In one example, when the automatic gain control operation is in the low speed mode, the measurement period in the measurement of the power of the received signal is set to one subframe.

  The details of the operation in FIG. 10 are the same as the operations of the wireless communication terminal based on FIGS.

  In an embodiment of the present invention, the wireless communication terminal is an electronic device on which an LTE chip is mounted, such as a mobile phone, a portable computer, a PDA, a data card, a USB stick, an in-vehicle receiver, a smart appliance, and an intelligent measuring instrument. Also good.

  Specific descriptions have been given of several embodiments of the present invention. As will be appreciated by those skilled in the art, all or any step or element of the method and apparatus of the present invention may be implemented in any computing device (including processors, storage media, etc.) or network of computing devices in hardware, firmware, software. Alternatively, a combination thereof can be realized. Since this can be realized with basic programming skills by those skilled in the art who understand the contents of the present invention, no specific description will be given here.

  Moreover, when performing the operation from the outside required in the above description, any appropriate display device and input device connected to any arithmetic device, a corresponding interface, and a control program may be used. That is, the related hardware and software in a computer, a computer system or a computer network, and the hardware, firmware, software, or a combination of each operation in the method for realizing the present invention, the apparatus of the present invention and each component thereof Is configured.

  Further, by understanding this specification, the present invention can be realized by executing one program or a set of programs in any information processing apparatus. The information processing apparatus may be a known general-purpose apparatus. Therefore, the present invention can be realized only by providing a program product including program code for realizing the method or apparatus. That is, such a program product and a medium storing such a program product also constitute the present invention. Of course, the storage may be any type of storage known to those skilled in the art or developed in the future.

  Of course, in the apparatus and method of the present invention, each element or step may be separated, integrated, and / or separated and then newly integrated. These separations and / or new combinations can be considered equivalents of the present invention. The steps of executing the series of processes may be executed in time series according to the order of description, but are not necessarily executed in time series. Some steps can be performed in parallel or independently of each other. Also, in the above description of specific embodiments of the invention, the features described and / or illustrated for one embodiment may be identical or similar to one or more other implementations. It can be used in the form, combined with features in other embodiments, or substituted for features in other embodiments.

  It should be noted that when the term “includes / has” is used in the text, it means the presence of a feature, element, step or component, but the presence or addition of one or more other features, elements, steps or components. Do not exclude.

  While the invention and its advantages have been specifically described, various changes, substitutions and transformations may be made without departing from the spirit and scope of the invention as defined by the appended claims. The technical scope of the present invention is not limited to specific examples of the processes, devices, means, methods, and steps described in the specification. Those skilled in the art will, from the published content of the present invention, develop according to the present invention, existing and future, which perform substantially the same functions or obtain substantially the same results as the corresponding embodiments described herein. It can be readily appreciated that processes, devices, means, methods or steps can be used. Accordingly, the appended claims are intended to include within their scope such processes, apparatus, means, methods, or steps.

The following additional notes are further disclosed for the embodiments including the above examples.
(Appendix 1) A wireless communication terminal,
Automatic gain control means for performing automatic gain control on a received signal of the wireless communication terminal;
Gap control means for controlling the start and end of the gap;
A gap operation specifying means for specifying an operation to be performed in the next gap;
Mode control means for setting the mode of the automatic gain control means in the next gap based on the specified operation;
A wireless communication terminal.
(Supplementary Note 2) The mode of the automatic gain control means includes a high speed mode, a low speed mode, and a stop mode, and the automatic gain control means has a gain value adjustment period in the low speed mode. The wireless communication terminal according to appendix 1, wherein the automatic gain control means is smaller and does not perform automatic gain control in the stop mode.
(Supplementary Note 3) The automatic gain control means has a gain value adjustment period in the high-speed mode smaller than or equal to the length of one subframe, while a gain value adjustment period in the low-speed mode is larger than the length of one subframe. The wireless communication terminal according to attachment 2.
(Supplementary Note 4) The operation performed in the next gap is one or more of gain value initial convergence operation, primary synchronization symbol detection operation, secondary synchronization symbol detection operation, gain value reconvergence operation, channel measurement operation and sleep operation. Including a plurality of
The mode control means sets the mode of the automatic gain control means in the next gap to the high speed mode when the operation performed in the next gap is a gain value initial convergence operation, a primary synchronization symbol detection operation or a secondary synchronization symbol detection operation. When the operation performed at the next gap is a gain refocusing operation or channel measurement operation, the mode of the automatic gain control means at the next gap is set to the low speed mode, and the operation performed at the next gap is the sleep operation. The wireless communication terminal according to appendix 2, wherein in some cases, the mode of the automatic gain control means in the next gap is set to a stop mode.
(Supplementary note 5) The wireless communication terminal according to supplementary note 2, wherein the automatic gain control means uses only one gain value for each gap in the low speed mode, and the gain value is generated in the previous gap.
(Supplementary Note 6) The automatic gain control means includes:
A gain generator for generating a gain value;
A variable gain amplifier that adjusts the amplitude of the received signal based on the gain value generated by the gain generator and outputs the adjusted signal;
An analog / digital converter that converts the signal output from the variable gain amplifier into a digital signal, and
The gain generator is
A power measurement module for measuring the power of the received signal;
A power comparison module that compares the measured power of the received signal with the target power to identify a power adjustment amount;
The wireless communication terminal according to attachment 2, further comprising: an averaging module that performs weighted averaging of the identified current power adjustment amount and the previous power adjustment amount.
(Supplementary note 7) The wireless communication terminal according to supplementary note 6, wherein the weight of the previous power adjustment amount is set to 0 in the averaging module when the automatic gain control means is in the high speed mode.
(Supplementary Note 8) The target power is the difference between the maximum quantized power of the analog / digital converter and a margin value, and when the automatic gain control means is in the high speed mode, the margin value is set to 9 to 36 dB. The wireless communication device according to appendix 6.
(Supplementary Note 9) The target power is obtained by subtracting the sum of the margin value and the offset value of the margin value from the maximum quantized power of the analog / digital converter, and the offset value of the margin value is the analog value. The wireless communication according to appendix 6, wherein the margin value is set to 9 to 36 dB when the automatic gain control means is in a high-speed mode and increases with a proportional increase in a signal clipped in the digital / digital converter. Terminal.
(Supplementary note 10) The wireless communication apparatus according to supplementary note 8 or supplementary note 9, wherein the margin value is set to 18 to 27 dB when the automatic gain control means is in a high-speed mode.
(Supplementary Note 11) When the automatic gain control means is in the high-speed mode, the measurement period of the power measurement module is the interval of the maximum time region of the reference signal in the received signal, or the maximum time of the reference signal in the received signal. It is set so that the length of one symbol is larger than the interval of each region, the measurement periods do not overlap each other, and the adjustment period of the gain value of the previous automatic gain control means is greater than or equal to the measurement period of the power measurement module The wireless communication terminal according to attachment 6.
(Supplementary Note 12) When the automatic gain control means is in the high-speed mode, the measurement period of the power measurement module is set to the interval of the maximum time region of the reference signal in the received signal, or the maximum time of the reference signal in the received signal. The supplementary note 6 is set such that the length of one symbol is larger than the interval of the areas, the measurement periods overlap each other, and the adjustment period of the gain value of the automatic gain control means is smaller than the measurement period of the power measurement module. Wireless communication terminal.
(Supplementary note 13) The ratio according to Supplementary note 6, wherein when the automatic gain control means is in the low speed mode, the ratio of the weight of the previous power adjustment amount and the weight of the current power adjustment amount is 1 to 9 in the average module. Wireless communication terminal.
(Supplementary Note 14) The target power is a difference between the maximum quantized power of the analog / digital converter and a margin value, the automatic gain control means is in a low speed mode, and the wireless communication terminal has already acquired the frame timing. The wireless communication terminal according to appendix 6, wherein the margin value is set to 9 to 36 dB when the frame arrangement is not acquired.
(Supplementary Note 15) When the automatic gain control means is in the low speed mode and the wireless communication terminal has already acquired the frame timing but has not acquired the frame arrangement, the margin value is 18 to 27 dB. 15. The wireless communication terminal according to appendix 14, which is set to
(Supplementary note 16) The wireless communication terminal according to supplementary note 6, wherein the measurement cycle of the power measurement module is set to one subframe when the automatic gain control means is in the low speed mode.
(Supplementary note 17) An automatic gain control method for a radio communication terminal,
Identifying the operations to be performed in the next gap,
A step of setting an automatic gain control operation mode in a next gap based on the specified operation, and a step of performing an automatic gain control operation on a received signal of the wireless communication terminal according to the set automatic gain control mode Including methods.
(Supplementary Note 18) The automatic gain control operation mode includes a high-speed mode, a low-speed mode, and a stop mode. The automatic gain control operation includes a gain value adjustment cycle in the low-speed mode. Item 18. The method of Item 17, wherein the method is smaller and does not perform an automatic gain control operation in the stop mode.
(Supplementary note 19) In the automatic gain control operation, the gain value adjustment period in the high-speed mode is smaller than or equal to the length of one subframe, while the gain value adjustment period in the low-speed mode is larger than the length of one subframe. The method according to appendix 18.
(Supplementary Note 20) The operation performed in the next gap is one or more of gain value initial convergence operation, primary synchronization symbol detection operation, secondary synchronization symbol detection operation, gain value reconvergence operation, channel measurement operation and sleep operation. Including a plurality of
The step of setting the mode of the automatic gain control operation in the next gap is performed when the operation performed in the next gap is a gain value initial convergence operation, a primary synchronization symbol detection operation, or a secondary synchronization symbol detection operation. When the automatic gain control operation mode is set to the high-speed mode and the operation to be performed in the next gap is the gain reconvergence operation or the channel measurement operation, the automatic gain control operation mode in the next gap is set to the low-speed mode. The method according to claim 18, further comprising the step of setting the mode of the automatic gain control operation in the next gap to the stop mode when the operation performed in the next gap is a sleep operation.

Claims (11)

A wireless communication terminal,
Automatic gain control means for performing automatic gain control on a received signal of the wireless communication terminal;
Gap control means for controlling the start and end of the gap;
A gap operation specifying means for specifying an operation to be performed in the next gap;
Mode control means for setting the mode of the automatic gain control means in the next gap based on the specified operation;
A wireless communication terminal. The mode of the automatic gain control means includes a high speed mode, a low speed mode, and a stop mode, and the automatic gain control means has a gain value adjustment period in the high speed mode smaller than a gain value adjustment period in the low speed mode, The wireless communication terminal according to claim 1, wherein the automatic gain control means does not perform automatic gain control in the stop mode. The automatic gain control means has a gain value adjustment period in the high speed mode smaller than or equal to the length of one subframe, while a gain value adjustment period in the low speed mode is larger than the length of one subframe. The wireless communication terminal described in 1. The operation performed in the next gap includes one or more of gain value initial convergence operation, primary synchronization symbol detection operation, secondary synchronization symbol detection operation, gain value reconvergence operation, channel measurement operation and sleep operation. ,
The mode control means sets the mode of the automatic gain control means in the next gap to the high speed mode when the operation performed in the next gap is a gain value initial convergence operation, a primary synchronization symbol detection operation or a secondary synchronization symbol detection operation. When the operation performed at the next gap is a gain refocusing operation or channel measurement operation, the mode of the automatic gain control means at the next gap is set to the low speed mode, and the operation performed at the next gap is the sleep operation. The radio communication terminal according to claim 2, wherein in some cases, the mode of the automatic gain control means in the next gap is set to a stop mode. The radio communication terminal according to claim 2, wherein the automatic gain control means uses only one gain value for each gap in the low speed mode, and the gain value is generated in the previous gap. The automatic gain control means includes
A gain generator for generating a gain value;
A variable gain amplifier that adjusts the amplitude of the received signal based on the gain value generated by the gain generator and outputs the adjusted signal;
An analog / digital converter that converts the signal output from the variable gain amplifier into a digital signal, and
The gain generator is
A power measurement module for measuring the power of the received signal;
A power comparison module that compares the measured power of the received signal with the target power to identify a power adjustment amount;
The wireless communication terminal according to claim 2, further comprising: an averaging module that performs weighted averaging of the identified current power adjustment amount and the previous power adjustment amount. The wireless communication terminal according to claim 6, wherein a weight of a previous power adjustment amount is set to 0 in the averaging module when the automatic gain control means is in a high-speed mode. When the automatic gain control means is in the high-speed mode, the measurement period of the power measurement module is equal to the maximum time domain interval of the reference signal in the received signal or from the maximum time domain interval of the reference signal in the received signal. The length of one symbol is set to be large, the measurement periods do not overlap with each other, and the adjustment period of the gain value of the previous automatic gain control means is greater than or equal to the measurement period of the power measurement module. The wireless communication terminal described in 1. When the automatic gain control means is in the high-speed mode, the measurement period of the power measurement module is equal to the maximum time domain interval of the reference signal in the received signal or from the maximum time domain interval of the reference signal in the received signal. 7. The wireless communication according to claim 6, wherein the length of one symbol is set to be large, the respective measurement cycles overlap each other, and the gain value adjustment cycle of the previous automatic gain control means is smaller than the measurement cycle of the power measurement module. Terminal. The wireless communication terminal according to claim 6, wherein when the automatic gain control means is in a low-speed mode, a ratio between a weight of a previous power adjustment amount and a weight of a current power adjustment amount is 1 to 9 in the average module. . An automatic gain control method for a wireless communication terminal, comprising:
Identifying the operations to be performed in the next gap,
A step of setting an automatic gain control operation mode in a next gap based on the specified operation, and a step of performing an automatic gain control operation on a received signal of the wireless communication terminal according to the set automatic gain control mode Including methods.

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