JP4890174B2 - Wireless communication apparatus and wireless communication method - Google Patents

Description

  The present invention relates to an AGC (Auto Gain Control) control and a radio communication method, particularly an AGC control method, in a radio communication device, particularly a radio device compliant with 3GPP (3rd Generation Partnership Project) standards such as a W-CDMA terminal.

  FIG. 9 is a block diagram showing a conventional example of a wireless communication apparatus to which the present invention is applied. An RF (Radio Frequency) receiving unit (radio receiving unit) 4 in the wireless communication apparatus 1 shown in the figure has a direct conversion receiver configuration that is mainstream in the above W-CDMA. Note that the RF transmission unit 7 paired with the RF reception unit 4 is not directly related to the AGC control according to the present invention, and the details thereof are omitted, but the transmission signal from the RF transmission unit 7 is transmitted. The antenna is shared with the antenna for receiving the reception signal from the RF receiving unit 4 through the duplexer (DP LX) 3. The antenna 2 in the figure is the shared antenna.

  The analog signal input from the antenna 2 is demodulated and amplified by the RF receiving unit 4 and further converted into a digital signal by the AFE unit (Analog Front-End unit: analog front end unit) 5. The data is input to a DBB unit (Digital Base Band unit: digital baseband unit) 6 where the AGC control is performed. The DBB unit 6 is followed by an AFC (Auto Frequency Control) unit, a DEM (Demodulation) unit that decodes a W-CDMA spread code, and a DECODE (Decoder) that performs decryption processing together with error correction. ) Part continues, but not shown.

  Here, the RF receiving unit 4, AFE unit 5, and DBB unit 6 will be further described as follows. First, looking at the RF receiver 4, the received signal input from the duplexer (DPLX) 3 is applied to an LNA unit (Low Noise Amplifier unit) 11. When the LNAon / off signal that is the control input is on, that is, when the received signal has a weak electric field strength, the LNA unit 11 performs signal amplification. On the other hand, when the signal is off, that is, when the electric field strength is strong, the signal simply passes through the signal.

  Next, the received signal that has passed through the LNA unit 11 is input to a BPF unit (Band Pass Filter unit: bandpass filter unit) 12, and noise frequency components included in the signal are removed, and then a QDEM unit (Quadrature Demodulator). Unit: quadrature demodulation unit) 13. In the QDEM unit 13, only the baseband component is extracted from the received signal composed of the baseband component and the carrier component carrying the baseband component. In this case, the I-ch reception baseband signal RxI and the Q-ch reception baseband signal RxQ are separated and extracted.

  The extracted signals RxI and RxQ are further removed by the LPF (Low Pass Filter unit: low-pass filter unit) 14 except for the required band components, and then the VGA unit (Variable Gain Amplifier unit: variable gain amplification unit) 15 is used. Then, variable gain amplification is performed in accordance with a GC (Gain Control) signal which is the control input. The output after amplification of the variable gain includes forward and inverted I-ch pair received signal “RxI (forward / inverted)” and forward and inverted Q-ch pair received signal “RxQ (forward / inverted)”. Is.

  The analog output signals received and processed by the RF receiver 4 as described above, that is, the RxI (forward / inverted) signal and the RxQ (forward / inverted) signal are input to the AFE unit 5 of the next stage, and the AFE Each is converted into a digital signal by an ADC section (Analog to Digital Converter section) 16 in the section. The RxI (forward / inverted) signal and the RxQ (forward / inverted) signal converted to the digital signal are further time-division multiplexed into a series of signals, and further supplied to the DBB unit 6 in the next stage as an RxIQ multiplexed signal. Entered. Reference numeral 18 in the AFE unit 5 is a DAC (Digital to Analog Converter) on the transmission side.

  The RxIQ multiplexed signal input to the DBB unit 6 is subjected to predetermined processing and calculation in an AGC (Auto Gain Control unit: gain automatic adjustment unit) 17 in the DBB unit, and the GC signal and the LNAon / off signal described above. Are transmitted to the VGA unit 15 and the LNA unit 11, respectively. The AGC unit 17 will be described in detail later with reference to FIG.

  The following [Patent Document 1] and [Patent Document 2] are known techniques related to the present invention. As will become apparent later, in the present invention, the abnormal gain control caused by the DC offset generated when the gain of each of the first amplifier (LNA) and the second amplifier (VGA) in the RF receiver 4 is changed is generated. During the period, normal AGC control is avoided by sleeping. On the other hand, [Patent Document 1] is characterized in that the timing of the gain change in the first amplifier is shifted from the timing of the gain change in the second amplifier, and [Patent Document 2] is characterized in that the gain change described above. Is suppressed to (previous setting gain + 4) [dB] when the increase is made.

JP 2004-328494 A JP 2004-193914 A

  In the wireless communication device 1 having the receiver configuration based on the direct conversion method shown in FIG. 9 described above, the gain change in the LNA unit 11 by the LNAon / off signal and the gain change in the VGA unit 15 by the GC signal. In some cases, a DC offset occurs in the output of the LGA unit 15. In the output of the VGA unit 15, when an AC signal component is superimposed on the DC offset component, the AC signal component may be saturated (see FIG. 11 described later).

  Eventually, due to the saturation of the AC signal component, the gain control in the AGC unit 17 does not operate normally, and the time until convergence to a desired gain is extended. That is, the gain convergence time becomes long. Then, there arises a problem that a predetermined gain convergence time defined by W-CDMA cannot be observed.

  Furthermore, it causes a problem that an error is caused in a received signal strength indication RSSI (Receive Signal Strength Indicator) which is one of important information used in the wireless communication apparatus. This is because the RSSI is obtained by calculation based on the time from the start of signal reception at the RF receiver 4 to the gain setting (LNAon / off and GC) to the RF receiver 4 after a predetermined time has elapsed. If this time becomes inaccurate due to the increase in the gain convergence time described above, naturally, the RSSI also includes an error.

  Therefore, in view of the above problems, the present invention provides a wireless communication apparatus and a wireless communication method capable of significantly reducing the gain convergence time as compared with the conventional technique even when a DC offset occurs in the output of the VGA unit. It is for the purpose.

  FIG. 1 is a diagram showing a basic configuration of an apparatus according to the present invention. Throughout the drawings, similar components are denoted by the same reference numerals or symbols.

  In FIG. 1, the radio receiver (RF receiver) 4 and the automatic gain adjuster (AGC unit) 17 are as shown in FIG. That is, the wireless reception unit (RF reception unit) 4 includes an amplification unit 21 that receives the reception signal (IN) and amplifies it. The amplifying unit 21 corresponds to the LNA unit 11 and the VGA unit 15 according to the example of FIG.

  On the other hand, the automatic gain adjustment unit (AGC unit) 17 performs gain control on the amplification unit 21 while updating the gain according to the output level from the RF reception unit 4 at every predetermined gain setting period. .

  The component that characterizes the present invention is the delay control unit 22. The delay control unit 22 has a function of delaying the gain control for the amplification unit 21 by a predetermined delay time from the start of each predetermined gain setting cycle.

The present invention can also be understood as a novel wireless communication method.
FIG. 2 is a flowchart representing the basic steps of the method according to the invention. In this figure,
Step S11: This is a step executed in the radio receiving unit 4 including at least the variable gain amplifying unit 21, and is a step for controlling the input received signal IN with the variable gain.

Step S12: This step S12 is composed of a conventional step S12b and a step S12a that characterizes the present invention.
In the step S12b, the gain automatic adjustment unit 17 updates the gain according to the output level from the radio reception unit 4 at every predetermined gain setting period, and controls the gain for the amplification unit 21 (11, 15). I do.

  On the other hand, in step S12a, the gain control is interrupted until a predetermined delay time elapses after the start of the predetermined gain setting cycle, and then the gain control is started.

  In each gain setting cycle described above, each time a new gain is set from the AGC unit 17 to the amplifying unit 21, a DC offset voltage due to this gain change is generated. As will be described later with reference to FIG. 11, this DC offset voltage causes saturation of the AC signal component, and as a result, lengthens the convergence time of the gain.

  Therefore, every time the gain setting period arrives, although gain setting is performed, the original gain control (AGC) is put to sleep for a while from the start time. By doing so, the gain control (AGC) is interrupted only during the saturation of the AC signal component due to the DC offset voltage, that is, during the gain instability period, and thereafter the stable gain control (AGC) is performed. As a result, the gain rapidly converges and the gain convergence time is significantly shortened compared to the conventional technique (see FIG. 4).

  In order to clarify the effect brought about by the present invention, first, a configuration example of the conventional AGC unit 17 and a process of convergence of gain when the conventional AGC unit 17 is used will be described.

  FIG. 10 is a diagram illustrating a configuration example of the conventional AGC unit 17. In this figure, the AGC unit 17 calculates a gain corresponding to the level of the RxIQ multiplexed signal output from the ADC unit 16 in the AFE unit 5 shown in FIG. 9, and based on the calculated gain, the LNA unit 11 The above-mentioned LNA on / off signal and the above-mentioned GC signal for the VGA unit 15 are generated, and the gain setting for the LNA unit 11 and the VGA unit 15 is performed.

More specifically, the RxIQ multiplexed signal that has been RxIQ time-division multiplexed is input to the IQ distributor 31 where it is distributed to the RxI signal and the RxQ signal. The power generation unit 32 performs an operation of P = I ² + Q ^{2 on the} distributed RxI / RxQ signal to calculate the power P.

  The calculated power P is input to a reference value difference integrator (loop filter) 33 in the next stage, where a constant output level that is a reference that the RxIQ multiplexed signal should have, that is, a “reference value” in the figure. And the difference is obtained, and the difference is further integrated. The difference integral value obtained here becomes the above-described GC (Gain Control) signal via the output setting unit 34, and sets the gain for the VGA unit 15. The output setting unit 34 performs a function of converting the data into a data format suitable for the input interface of the RF receiving unit 4.

  On the other hand, the difference integrated value from the reference value difference integrator 33 is input to the LNA switching determination unit 35. When it is determined that the difference integrated value is significantly lower than the reference value, the LNA on / off signal for the LNA 11 is switched on. . That is, it instructs the LNA 11 to perform low noise amplification. On the other hand, when it is determined that the value is significantly higher than the reference value, the LNAon / off signal is switched to off. That is, the LNA 11 passes the received signal through.

  When the above LNAon / off signal is on, that is, when the LNA unit 11 has gain, if the gain of the LNA unit 11 is included in the gain (GC) for the VGA unit 15, the correct GC signal Therefore, the LNA gain correction unit 36 is provided to compensate the reference value difference integrator 33 so as to reduce the extra gain.

  FIG. 11 shows a gain convergence process when the AGC unit 17 having such a conventional configuration is used. In this figure, the horizontal axis t represents the elapsed time [sec] since the AGC unit 17 started the gain control operation, and T which is a unit of scale such as T, 2T, 3T. Represents the start time of each set cycle. The vertical axis Grf represents the set gain [dB] specified from the AGC unit 17 to the RF receiving unit 4.

  In FIG. 11, first, when the gain control operation by the AGC unit 17 is started at t = 0, the gain is set by the AGC unit 17 at a constant time interval (a constant cycle). The starting point of the gain setting period is the above T [sec]. When the first gain setting is performed for the RF receiver 4 at this T [sec], the above-described DC offset voltage is generated at the output of the VGA unit 15 in the RF receiver. The signal component is saturated. Due to the saturation of the AC signal component, the AGC unit 17 tries to amplify the no signal. As a result, as shown in FIG. 11, in the next 2T [sec], the set gain for the VGA unit 15 increases excessively, and a DC offset voltage is generated. After that, the gain gradually converges, and converges to the final stable gain after 1 / T [sec] in the example of the figure, and after the convergence, a constant RF gain (after the convergence corresponding to a predetermined signal amplitude) It takes a considerable amount of time to settle down to Gs) in the figure.

  Therefore, the present invention aims to shorten the set gain convergence time by introducing the delay control unit 22 shown in FIG. A configuration example in which the delay control unit 22 is integrated with the AGC unit 17 is shown in the figure.

  FIG. 3 is a diagram showing a configuration example of the AGC unit 17 based on the present invention. In the figure, a notable component is a delay control unit 22. The switch (SW) 23 is controlled by the delay control unit 22. Furthermore, the internal register 24 cooperates with the delay control unit 22. The other components (31 to 36) are the same as the corresponding components shown in FIG. 10, and their functions are also substantially the same.

The functions of the delay control unit 22 and the switch (SW) 23 and the internal register 24 cooperating with the delay control unit 22 will be described with reference to the drawings.
FIG. 4 is a diagram showing a gain convergence process when the AGC unit 17 according to the present invention shown in FIG. 3 is used. The effect of the present invention becomes clear by comparing FIG. 4 with FIG. 11 described above. The horizontal axis t in FIG. 4 represents the elapsed time [sec] since the AGC unit 17 started the gain control operation, and the vertical axis Qrf represents the set gain [designated to the RF receiving unit 4 from the AGC unit 17]. dB], which is exactly the same as in FIG. FIG. 5 is a diagram showing a specific IC configuration example of the wireless communication apparatus 1 according to the present invention.

  In FIG. 4, when the gain control operation by the AGC unit 17 is started at t = 0, the gain for the VGA unit 15 and the LNA unit 11 in the RF receiving unit 4 is set at a constant time interval (fixed period) T [sec]. Settings are made. Before starting the gain control, when the power is turned on to the MODEM 41 in the DBB-LSI 6 shown in FIG. Captured in memory 24 (also shown in FIG. 5).

  The initial delay time Wfirst [sec] held in the nonvolatile memory 42 is given from the start of the gain control operation (t = 0) to the start time (t = T) of the first gain setting cycle. The Wfirst is preferably matched with the generation time of the DC offset voltage at the output of the VGA unit 15. During the Wfirst period, the gain control is artificially interrupted by the delay control unit 22 of FIG. This interruption can be easily performed by switching the contact in the switch (SW) 23 in FIG. 3 from the terminal A side to the terminal B side. Normally, the contact point is on the terminal A side, and as described with reference to FIG. 10, the reference value difference integrator (loop filter) 33 compares the power P from the power generating unit 32 with the reference value, Although the AGC operation is performed, the contact of the switch 23 is switched to the terminal B side by the delay control unit 22 during the period of Wfirst. Then, the reference value difference integrator 33 performs comparison between the reference values, and the comparison result is zero. That is, the AGC operation is substantially suspended (sleep). Here, the above interruption is realized. Thus, although the gain is set, the AGC control operation is stopped during the interruption.

  Since T = 0, T, 2T, and so on have elapsed, new gain settings should be made at T and 2T (see T and 2T in FIG. 10). However, in FIG. 4 according to the present invention, since T [sec] and 2T [sec] are in the period of Wfirst, there is no gain change at T [sec] and 2T [sec] due to the interruption.

The original gain control is started only after the elapse of Wfirst, and the gain is set to the VGA unit 15 at 4T [sec] in FIG. Thereafter, a difference ΔG ₁ between the initially set gain and the gain set at the time of 4T [sec] is calculated by the difference calculating means 25 in the delay control unit 22.

Further, the delay time W ₁ corresponding to the difference ΔG ₁ is calculated by the delay time calculation means 26 in the delay control unit 22. The calculated delay time W ₁ is given at 4T [sec]. Then, the gain control is again interrupted between 4T [sec] and (4T + W ₁ ) [sec], and after (4T + W ₁ ) [sec] has elapsed, the gain control is started again, and after 5 T [sec], the VGA is resumed. The gain is set in the unit 15.

In this case, the difference calculation means 25 calculates the difference between the gain set at 4T [sec] and the gain set at 5T [sec]. This calculated difference is ΔG ₂ . Then, the delay time W ₂ corresponding to the difference ΔG ₂ is calculated by the delay time calculation means 26. The delay time W ₂ [sec] calculated here is given in the above 5T [sec], and the gain control is interrupted during the period of 5T to (5T + W ₂ ) [sec].

  The above operation is repeated a predetermined number of times. In other words, the number of gain setting cycles for providing the delay time is limited in advance by a predetermined number of times, and the above operation is repeated by that number.

  Thus, according to an example, the gain convergence time is 6 T [sec] shown in FIG. 4 from the conventional 11 [sec] (see FIG. 11), and a time reduction of 5 T [sec] can be realized.

  A preferred specific example of the operation of the wireless communication apparatus 1 of the present invention, particularly the operation of the delay control unit 22 shown in FIG. 3, is summarized as follows.

(I) The delay times W ₁ , W ₂ ... May be arbitrarily specified without being proportional to ΔG ₁ , ΔG ₂ .

  (Ii) The above-mentioned arbitrarily designated delay time may be held in the nonvolatile memory 42 in advance.

  (Iii) The number of gain setting periods (T, 2T, 3T...) To be delayed by the delay time can be arbitrarily specified. That is, it is preferable to stop the gain control described above at an appropriate number of times.

  (Iv) The number of gain setting cycles arbitrarily designated in the above (iii) may be held in the nonvolatile memory 42 in advance.

  (V) The above-described difference calculating means 25 for calculating the difference between the gain previously set by the automatic gain adjusting unit 17 and the gain set this time can be provided. For example, this is provided in the delay control unit 22.

(Vi) The delay time calculating means 26 described above that calculates the length of the delay time according to the difference (ΔG ₁ , ΔG ₂ ...) Calculated by the difference calculating means 25 of (v) above can be provided. . For example, this is provided in the delay control unit 22.

(Vii) When the difference (ΔG ₁ , ΔG ₂ ...) Between the gain previously set by the automatic gain adjustment unit 17 and the gain set this time is obtained by having the correspondence table 43 described above, the difference and delay are obtained in advance. The delay time can be determined with reference to the correspondence table 43 that records the correspondence with time.

  (Viii) When the delay time exceeds the start point of the next gain setting cycle, the gain control in the gain setting cycle is interrupted.

Finally, a detailed operation example of the delay control unit 22 shown in FIG. 3 is shown.
FIG. 6 is a flowchart (part 1) illustrating a detailed operation example of the delay control unit 22,
FIG. 7 is the same flowchart (part 2).
FIG. 8 is the same flowchart (No. 3).

With reference to FIGS.
In step S201 of FIG. 6, the initial setting process shown in the figure is performed. Among these, the “AGC input signal switching SW” will be described in more detail. The switching logics L and H of the switching SW 23 are connected to the actual signal input side (the power generation unit 32 side in FIG. 3) when L, and when H Is connected to the reference value side shown in FIG. “Timer” is an internal timer and counts up in the range of 0 to T in FIG. In addition, the meanings of major symbols appearing in this flowchart are defined again as follows.

Gnow: current setting gain Gbefore: previous setting gain W: delay time setting value ΔG: difference between current setting gain and previous setting gain T: AGC gain setting cycle

  In step S202, there is no processing by the delay control unit 22 until the Timer count-up has expired (No), that is, until the above T [sec] has elapsed from the start of the AGC operation.

In step S203, when the above-mentioned Timer count-up expires (Yes), the Timer is reset,
In step S204, the initial gain setting flag is turned ON.
Step S205 is the head of the iterative process that is performed when the set number n of delay times is not 0 in step S225 of FIG.

In step S206, after the current set gain Gnow is written in a set gain register (not shown),
In step S207, it is confirmed whether the initial setting flag is ON.

In step S208 of FIG. 7, when the flag is confirmed to be ON (Yes), the delay time setting value W is set to Wfirst (see FIG. 4),
In step S209, the initial setting flag is reset from ON to OFF.

In step S210, when the result of step S207 is No, the gain transmission cancel flag indicating that the gain setting from the AGC unit 17 to the RF receiving unit 4 has been canceled (for example, No in step S216) is ON. If not (No),
In step S211, the difference calculation means 25 in FIG. 3 calculates ΔG, which is the absolute value of the difference between the current setting gain Gnow and the previous setting gain Gbefore.
In step S212, using the calculated ΔG,
a) Referring to the correspondence table 43 described above, W corresponding to the ΔG is set, or b) W is obtained and set by a simple calculation formula using the ΔG, for example, a proportional calculation formula.

In step S213, when the result of step S210 is Yes, that is, when the transmission of the gain is canceled, a value obtained by subtracting the period T from the previous delay time W is set as the current delay time setting value W.
In step S214, the gain transmission cancel flag is returned to OFF.

In step S215, after any of the above steps S209, S212, and S214 is completed, the previous set gain Gbefore is switched to the current set gain Gnow,
In step S216, it is determined whether the set delay time W has exceeded the gain setting period T.

  In addition, in FIG. 7, each step of the part surrounded by dotted lines (2), (6, 7, 8) and (9) is the embodiment of the present invention at the end after the explanation of the flowchart of FIG. Of (Appendix 1) to (Appendix 10) described as (Appendix 2), (Appendix 6) to (Appendix 8), and (Appendix 9), respectively.

In Step S217 of FIG. 8, when the result of Step S216 is No, it is subsequently determined whether or not the Timer count-up time is longer than the set delay time W.
In step S218, if it is determined that the length is long (Yes), the setting of the switch (SW) 23 in FIG. That is, it connects to the output side of the electric power unit 32, and in step S219, if the determination in step S217 is negative (No), the setting of the switch (SW) 23 is set to H. That is, the connection is made so that the reference value of FIG.

In step S220, after the end of step S218 or S219, it is determined whether or not the Timer count-up has expired, and if it has expired (Yes),
In step S221, the Timer is reset, and the set number n of delay times described above is incremented by +1.

In step S222, when the determination result in step S216 is No, that is, when W exceeds T, the gain transmission cancel flag is set to ON,
In step S223, the switch (SW) 23 of FIG. 3 is connected to the reference value side. In other words, stop the AGC operation,
In step S224, the timer waits for the count-up to expire.

In step S225, when the set number n of delay times becomes 0 after the end of step S221 or S224,
In step S226, the series of gain control interruption processing is terminated, and the switch (SW) 23 is connected again to the power generating unit 32 side, and a normal AGC control operation not including interruption processing is started.

The embodiment of the present invention described in detail above is as follows.
(Appendix 1)
A radio receiving unit including an amplifying unit for inputting and amplifying the received signal;
A gain automatic adjustment unit that performs gain control on the amplification unit while updating to a gain according to an output level from the wireless reception unit for each predetermined gain setting cycle,
A radio communication apparatus, comprising: a delay control unit that delays gain control for the amplification unit by a predetermined delay time from the start of each predetermined gain setting cycle.

(Appendix 2)
The wireless communication apparatus according to appendix 1, wherein the delay time can be arbitrarily designated.

(Appendix 3)
The wireless communication apparatus according to appendix 2, further comprising: a non-volatile memory that holds in advance the arbitrarily designated delay time.

(Appendix 4)
The wireless communication apparatus according to appendix 1, wherein the number of gain setting periods to be delayed by the delay time can be arbitrarily specified.

(Appendix 5)
The wireless communication apparatus according to appendix 4, further comprising: a nonvolatile memory that holds in advance the number of gain setting cycles that are arbitrarily designated.

(Appendix 6)
The wireless communication apparatus according to appendix 1, further comprising difference calculation means for calculating a difference between a gain set last time by the automatic gain adjustment unit and a gain set this time.

(Appendix 7)
The wireless communication device according to appendix 6, further comprising delay time calculation means for calculating the length of the delay time according to the difference calculated by the difference calculation means.

(Appendix 8)
When the difference between the previously set gain and the currently set gain is obtained by the automatic gain adjustment unit, the correspondence table is recorded in advance, and the correspondence relationship between the difference and the delay time is recorded. The wireless communication apparatus according to appendix 1, wherein the delay time is determined.

(Appendix 9)
The wireless communication apparatus according to appendix 1, wherein when the delay time exceeds a start time of the next gain setting cycle, the gain control in the gain setting cycle is interrupted.

(Appendix 10)
In a wireless receiver including at least a variable gain amplifier, a first step of amplifying the input received signal with the variable gain;
And a second step of performing gain control on the amplifying unit while updating the gain according to the output level from the wireless receiving unit every predetermined gain setting period in the automatic gain adjusting unit. Because
In the second step, there is provided a step of interrupting the gain control until a predetermined delay time elapses from a start time of the predetermined gain setting cycle, and thereafter starting the gain control. Wireless communication method.

It is a figure which shows the basic composition of the apparatus which concerns on this invention. 4 is a flowchart representing the basic steps of the method according to the invention. It is a figure which shows the example of 1 structure of the AGC part 17 based on this invention. It is a figure showing the convergence process of the gain at the time of using the AGC part 17 of FIG. 3 based on this invention. It is a figure which shows the specific IC structural example of the radio | wireless communication apparatus 1 based on this invention. 5 is a flowchart (part 1) illustrating a detailed operation example of the delay control unit 22; 6 is a flowchart (part 2) illustrating a detailed operation example of the delay control unit 22; 12 is a flowchart (part 3) illustrating a detailed operation example of the delay control unit 22; It is a block diagram which shows the prior art example of the radio | wireless communication apparatus with which this invention is applied. It is a figure which shows the example of 1 structure of the conventional AGC part 17. FIG. It is a figure showing the convergence process of the gain at the time of using the conventional AGC part 17 shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wireless communication apparatus 4 RF receiving part 5 AFE part 6 DBB part 7 RF transmission part 11 LNA part 12 BPF part 13 QDEM part 14 LPF part 15 VGA part 16 ADC part 17 AGC part 21 Amplifying part 22 Delay control part 23 Switch (SW )
24 Internal Register 25 Difference Calculation Unit 26 Delay Time Calculation Unit 31 IQ Distribution Unit 32 Power Generation Unit 33 Reference Value Difference Integrator 34 Output Setting Unit 35 LNA Switching Determination Unit 36 LNA Gain Correction Unit 41 MODEM Unit 42 Nonvolatile Memory 43 Corresponding Table

Claims (3)

A radio receiving unit including an amplifying unit for inputting and amplifying the received signal;
A gain automatic adjustment unit that performs gain control on the amplification unit while updating the gain according to the output level from the radio reception unit,
The gain control performed at predetermined time intervals according to the output level from the radio reception section to said amplifying unit, from the time that triggers the start of the gain control, the amplifier section due to gain variations in said time points A wireless communication apparatus , comprising: a delay control unit configured to prevent the gain control from being performed until a delay time corresponding to a DC offset generation time generated in step 1 elapses .   2. The wireless communication apparatus according to claim 1, wherein the delay time can be arbitrarily designated. In a wireless receiver including at least a variable gain amplifier, a first step of amplifying an input received signal with the variable gain;
A second step of performing gain control on the amplification unit while updating to a gain according to an output level from the wireless reception unit in an automatic gain adjustment unit,
In the second step, the gain control performed at predetermined time intervals in response to the output level, from the time that triggers the start of the gain control, resulting in the amplification unit due to gain variations in said time points Until the delay time corresponding to the DC offset occurrence time elapses, the gain control according to the output level from the radio reception unit to the amplification unit is not performed , and the gain control is performed after the delay time elapses. A wireless communication method comprising the step of starting.

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