JP2003143247A - Wireless communication apparatus and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wireless communication apparatus that can take frequency synchronization even on the occurrence of phase rotation of π/4 or over at one period interval so as to attain phase compensation with high accuracy. SOLUTION: The wireless communication apparatus includes: a frequency synchronization control means 20 that corrects a frequency of a reference signal by using an average value of phase difference data of several symbols or two symbols or over as to an inputted time to take frequency synchronization with a received signal so that the received signal has a frequency within a prescribed frequency error range; and a phase compensation control means 30 that applies adaptive control to a phase of the received signal when the frequency synchronization is taken so that the frequency error of the reference signal with respect to that of the received signal is brought into a prescribed range by the frequency control of the frequency synchronization control means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to digital phase modulation (PSK), differential phase modulation (DSK).
PSK: Differential Phase Shift Keying, QAM: Quadrature Amplitude Modulation
, A wireless communication device that performs frequency synchronization based on phase difference data of a received signal in a time interval shorter than a symbol interval, and a computer-readable recording medium recording a program for causing a computer to execute the function of the wireless communication device. Regarding

[0002]

2. Description of the Related Art Conventionally, quadrature amplitude modulation (QAM) system and digital phase modulation (PS) have been used as digital modulation systems.
In digital communication using the K) method, the Costas method or the like has been used as a method for performing phase synchronization. In this phase synchronization method, for example, in a digital modulation method such as QPSK, a phase of π / 4 is taken at a constant cycle, so a quadruple angle is obtained at the constant cycle interval, and the phase error is corrected by that value. Therefore, there is an unstable factor of π / 2, and it is impossible to correct a large frequency error that causes a phase error of π / 4 or more in a constant cycle.

[0003]

In narrow band digital communication, the influence of this frequency offset becomes very large because the symbol rate is small. Therefore, when the synchronization method using the Costas method is used, the symbol interval is π /
There is a problem that a highly accurate oscillator for frequency synchronization that does not cause a phase error of 4 or more is required, resulting in high cost.

Further, adaptive phase control using a linear equalization algorithm is used as a synchronization acquisition method for performing high-speed frequency synchronization. Although these methods can also perform high-speed frequency synchronization, a training signal is used. There is a problem that synchronization acquisition becomes impossible at a frequency at which a phase error of π / 4 or more occurs, such as when the QPSK modulation is required or when the phase difference in a constant cycle is QPSK modulation as in the Costas method.

Japanese Patent No. 2743826 discloses that a slave station receives a transmission signal from the master station for frequency synchronization with the master station and reproduces a reference clock from the received signal.
A wireless communication system that detects a frequency difference between the reproduction reference clock and a carrier reference signal (reference clock) of a burst signal to be transmitted, and controls so as to change the frequency of the carrier reference signal so that the frequency difference becomes constant. Proposed.

In this wireless communication system, a frequency counter is required for frequency error detection, and if the frequency of the carrier reference signal for transmission is made to follow the frequency of the reference clock included in the received signal so as to capture the synchronization with high accuracy. However, there is a problem that phase jitter occurs. Further, since the reference clock reproduced from the received signal is used for frequency synchronization, there is an influence of the phase change due to the modulation. It is particularly susceptible to communication in which the modulation band is narrowed.

Further, Japanese Patent Laid-Open No. 5-75662 and Japanese Patent Laid-Open No. 6-326740 describe techniques for ensuring phase synchronization, but both of them have problems with phase synchronization when there is a phase error of π / 4 or more. However, the problem of causing phase jitter has not been solved.

Further, Japanese Unexamined Patent Publication No. 6-318963 and Japanese Unexamined Patent Publication No. 6-197140 describe a method of arbitrarily offsetting a frequency to cope with a phase error of π / 4 or more, but a frequency offset is given. The method may be erroneous when the data is biased, and has a problem that the frequency synchronization control becomes unstable.

Japanese Unexamined Patent Publication (Kokai) No. 6-261089 discloses a technique for correcting the phase error of π / 4 or more by shortening the sampling interval, but the phase difference is calculated within one symbol, and the phase difference and the phase are calculated. The phase error is calculated from the rotation direction (polarity). As described above, the method of obtaining the phase difference within one symbol has a problem because it is influenced by the phase jitter and the like. There is ambiguity when there is a phase rotation of π / 4 or more. Furthermore, when passing through the band limiting filter, the determination based on the polarity becomes a problem such as when the roll-off coefficient is small.

The present invention has been made in view of the above circumstances, and is a case where a phase rotation of π / 4 or more occurs at one cycle interval without using a highly accurate oscillator for frequency synchronization. It is also an object of the present invention to provide a wireless communication device capable of frequency synchronization and capable of highly accurate phase compensation, and a recording medium recording a program for realizing the function of the wireless communication device.

[0011]

In order to achieve the above object, the invention according to claim 1 provides a digital phase modulation (PS).
K), in a radio communication device that performs frequency synchronization based on phase difference data of a received signal in a time interval shorter than the symbol interval, an average value over a time period in which several or more symbols or two or more symbols of the phase difference data are input. Frequency synchronization control means for correcting the frequency of the reference signal for performing frequency synchronization using, and whether the frequency error of the received signal with respect to the reference signal is within a predetermined range as a result of the frequency correction of the reference signal. The frequency synchronization control means adaptively adjusts the sampling number and sampling time of the phase difference data, which is the target of the average value calculation, according to the magnitude of the frequency error. When the state in which the frequency error is within a predetermined range is detected by the frequency error detection means, Characterized by starting communication to the transmitting side on the basis of the Kino frequency.

According to the first aspect of the invention, in the radio communication device using digital phase modulation (PSK), frequency synchronization is performed based on phase difference data of a received signal in a time interval shorter than a symbol interval. More than a few symbols of the phase difference data or 2 by the control means
Since the frequency of the reference signal for frequency synchronization is corrected using the average value over the time when more than symbols are input, it is possible to use π / Frequency synchronization can be performed even when four or more phase rotations occur. Also,
The frequency synchronization control means adaptively controls the number of samplings and the increase / decrease in the sampling time of the phase difference data to be the target of the average value calculation according to the magnitude of the frequency error. Can be improved.

Further, when the frequency error detection means detects that the frequency error of the received signal with respect to the reference signal is within a predetermined range as a result of frequency correction of the reference signal, transmission is performed based on the frequency at that time. Since the communication to the side is started, the need for frequency synchronization acquisition on the transmitting side can be reduced.

According to a second aspect of the present invention, there is provided a radio communication device for performing frequency synchronization based on phase difference data of a received signal in a time interval shorter than a symbol interval, using differential phase modulation (DPSK). Frequency synchronization control means for correcting the frequency of the reference signal for frequency synchronization using an average value over a time period in which several symbols or more or two symbols or more of the phase difference data are input, and a result of frequency correction of the reference signal. A frequency error detecting means for detecting whether or not a frequency error of the received signal with respect to the reference signal is within a predetermined range, and the frequency synchronization control means is provided for the phase difference data to be an average value calculation target. The number of samplings and the increase or decrease of the sampling time are adaptively controlled according to the magnitude of the frequency error, and the frequency error detecting means is used. Wherein when the frequency error has been detected state is within a predetermined range, and wherein the initiating communication to the transmitting side based on the frequency at that time.

According to the second aspect of the present invention, differential phase modulation (DPSK) is used, and the frequency between the mobile station and the base station is based on the phase difference data of the received signal in the time interval shorter than the symbol interval. In a communication control method of a wireless communication system for performing synchronization, a frequency of a reference signal for performing frequency synchronization is corrected by using an average value over a time period in which several symbols or two symbols of the phase difference data are input. Therefore, frequency synchronization can be performed even if a phase rotation of π / 4 or more occurs at one cycle interval without using a high-precision frequency synchronization oscillator. Further, the frequency synchronization control means adaptively controls the increase and decrease of the sampling number and sampling time of the phase difference data to be the target of the average value calculation according to the magnitude of the frequency error. The detection accuracy can be improved.

Further, as a result of frequency correction of the reference signal, when the frequency error detecting means detects a state where the frequency error of the received signal with respect to the reference signal is within a predetermined range, transmission is performed based on the frequency at that time. Since the communication to the side is started, the need for frequency synchronization acquisition on the transmitting side can be reduced.

Further, the invention according to claim 3 is a wireless communication apparatus for performing frequency synchronization based on phase difference data of a received signal in a time interval shorter than a symbol interval, using quadrature amplitude modulation (QAM). Frequency synchronization control means for correcting the frequency of a reference signal for frequency synchronization using an average value over a time period in which more than two symbols or more than two symbols of phase difference data are input; and a result of frequency correction of the reference signal, A frequency error detection means for detecting whether or not a frequency error of the received signal with respect to the reference signal is within a predetermined range, and the frequency synchronization control means is a sampling of the phase difference data to be an object of average value calculation. The number and the increase / decrease in sampling time are adaptively controlled according to the magnitude of the frequency error, and by the frequency error detecting means. If the serial frequency error has been detected state is within a predetermined range, and wherein the initiating communication to the transmitting side based on the frequency at that time.

According to the third aspect of the present invention, in the radio communication device that uses quadrature amplitude modulation (QAM) modulation and performs frequency synchronization based on phase difference data of a received signal in a time interval shorter than a symbol interval, Since the synchronization control means corrects the frequency of the reference signal for frequency synchronization by using the average value over the time when several symbols or more or two symbols of the phase difference data are input, the frequency synchronization with high accuracy is performed. It is possible to perform frequency synchronization even if a phase rotation of π / 4 or more occurs at one cycle interval without using an oscillator for. Further, the frequency synchronization control means adaptively controls the increase and decrease of the sampling number and sampling time of the phase difference data to be the target of the average value calculation according to the magnitude of the frequency error. The detection accuracy can be improved.

Further, as a result of frequency correction of the reference signal, when the frequency error detection means detects a state where the frequency error of the received signal with respect to the reference signal is within a predetermined range, transmission is performed based on the frequency at that time. Since the communication to the side is started, the need for frequency synchronization acquisition on the transmitting side can be reduced.

The invention according to claim 4 is the same as claim 1.
In the wireless communication device according to any one of 1 to 3, the receiving operation is performed under a state in which the frequency error detecting unit detects a state where the frequency error is within a predetermined range, the receiving operation is temporarily stopped, and then the receiving operation is performed again. When reception is started, frequency synchronization control is performed by the frequency synchronization control means using the frequency of the reference signal at that time so that the frequency error of the received signal with respect to the reference signal falls within a predetermined range, and then reception is stopped. After that, when the reception is started again, the frequency of the reference signal used in the previous reception operation is used in the current reception operation.

According to the invention described in claim 4, since the frequency of the reference signal used for the frequency synchronization control of the wireless communication device is the frequency used in the previous reception operation, In addition to the effect obtained by the invention described in any one of 3), the time required for the frequency synchronization control of the reference signal can be shortened even if the ambient temperature of the wireless communication device changes due to changes in the surrounding environment or self-heating.

The invention described in claim 5 is the same as claim 1.
3. In the wireless communication device according to any one of 1 to 3, the control data for controlling the frequency of the reference signal corresponding to the frequency correction amount for frequency synchronization obtained by the frequency correction control by the frequency synchronization control unit is set to the phase. Compensation with a compensation value according to the phase compensation amount obtained by the adaptive phase control by the compensation control means, setting the frequency of the reference signal by the compensated control data, and then starting communication to the transmitting side. Characterize.

According to the fifth aspect of the present invention, the control data for controlling the frequency of the reference signal corresponding to the frequency correction amount for frequency synchronization obtained by the frequency correction control by the frequency synchronization control means, Correction is performed with a correction value according to the amount of phase compensation obtained by the adaptive phase control by the phase compensation control means, and after setting the frequency of the reference signal by the corrected control data, communication to the transmitting side is started. Therefore, in addition to the effect obtained by the invention according to any one of claims 1 to 3, the phase compensation of the received signal can be performed with high accuracy on the transmission side.

The invention described in claim 6 is the same as claim 5
In the wireless communication device described in the paragraph 1, the control data for controlling the frequency of the reference signal corresponding to the frequency correction amount for frequency synchronization obtained by the frequency correction control by the frequency synchronization control means is adapted by the phase compensation control means. It is characterized in that the frequency is corrected by a correction value according to the phase compensation amount obtained by the phase control, and the frequency of the reference signal set by the corrected control data is used at the next reception.

According to the invention described in claim 6, the control data for controlling the frequency of the reference signal corresponding to the frequency correction amount for frequency synchronization obtained by the frequency correction control by the frequency synchronization control means is phase compensated. The correction is performed with a correction value according to the phase compensation amount obtained by the adaptive phase control by the control means, and the frequency of the reference signal set by the corrected control data is used at the next reception. In addition to the effect obtained by the invention described in (1), the phase compensation of the received signal can be performed with high accuracy at the next reception.

According to a seventh aspect of the present invention, in the wireless communication device using digital phase modulation (PSK), frequency synchronization is performed based on phase difference data of a received signal in a time interval shorter than a symbol interval. Frequency synchronization control means for correcting the frequency of a reference signal for frequency synchronization using an average value over a time period in which more than two symbols or more than two symbols of phase difference data are input; and a result of frequency correction of the reference signal, A frequency error detection means for detecting whether or not a frequency error of the received signal with respect to the reference signal is within a predetermined range, and the frequency synchronization control means is a sampling of the phase difference data to be an object of average value calculation. The number and the increase / decrease in sampling time are adaptively controlled according to the magnitude of the frequency error, and the frequency error detecting means A program for realizing the function of a wireless communication device, characterized in that, when a state in which the frequency error is within a predetermined range is detected, communication with the transmitting side is started based on the frequency at that time. The gist is a computer-readable recording medium that has been recorded.

According to the invention of claim 7, the program for realizing the function of the wireless communication device is recorded in a computer-readable recording medium. Therefore, the program recorded in this recording medium is recorded. Claim 1 by loading and executing
The same effect as that obtained by the invention described in (1) can be obtained.

The invention according to claim 8 is the wireless communication device for performing frequency synchronization based on phase difference data of a received signal in a time interval shorter than a symbol interval, using differential phase modulation (DPSK). Frequency synchronization control means for correcting the frequency of the reference signal for frequency synchronization using an average value over a time period in which several symbols or more or two symbols or more of the phase difference data are input, and a result of frequency correction of the reference signal. A frequency error detecting means for detecting whether or not a frequency error of the received signal with respect to the reference signal is within a predetermined range, and the frequency synchronization control means is provided for the phase difference data to be an average value calculation target. The number of samplings and the increase or decrease of the sampling time are adaptively controlled according to the magnitude of the frequency error, and the frequency error detecting means is used. When a state in which the frequency error is within a predetermined range is detected, communication with the transmitting side is started based on the frequency at that time, and a program for realizing the function of the wireless communication device is recorded. The computer-readable recording medium described above is a gist.

According to the eighth aspect of the invention, since the program for realizing the function of the wireless communication device is recorded in a computer-readable recording medium, the program recorded in this recording medium is recorded. The method according to claim 2, wherein the program is read into a computer system and executed.
The same effect as that obtained by the invention described in (1) can be obtained.

Further, the invention according to claim 9 is a radio communication apparatus which performs frequency synchronization based on phase difference data of a received signal in a time interval shorter than a symbol interval by using quadrature amplitude modulation (QAM). Frequency synchronization control means for correcting the frequency of a reference signal for frequency synchronization using an average value over a time period in which more than two symbols or more than two symbols of phase difference data are input; and a result of frequency correction of the reference signal, A frequency error detection means for detecting whether or not a frequency error of the received signal with respect to the reference signal is within a predetermined range, and the frequency synchronization control means is a sampling of the phase difference data to be an object of average value calculation. The number and the increase / decrease in sampling time are adaptively controlled according to the magnitude of the frequency error, and by the frequency error detecting means. When a state where the frequency error is within a predetermined range is detected, a program for realizing the function of the wireless communication device characterized by starting communication to the transmitting side based on the frequency at that time is recorded. The computer-readable recording medium described above is a gist.

According to the ninth aspect of the invention, since the program for realizing the function of the wireless communication device is recorded in a computer-readable recording medium, the program recorded in this recording medium is recorded. The method according to claim 3, wherein the program is read into a computer system and executed.
The same effect as that obtained by the invention described in (1) can be obtained.

A tenth aspect of the present invention provides a computer-readable recording medium in which a program for realizing the function of the wireless communication apparatus according to the fourth aspect is recorded.

According to the tenth aspect of the invention, since the program for realizing the function of the wireless communication device is recorded in a computer-readable recording medium, the program recorded in this recording medium is recorded. By loading the above into a computer system and executing it, the same effect as the effect obtained by the invention according to the fourth aspect can be obtained.

The invention according to claim 11 provides a computer-readable recording medium in which a program for realizing the function of the wireless communication device according to claim 5 is recorded.

According to the eleventh aspect of the present invention, the program for realizing the function of the wireless communication device is recorded in a computer-readable recording medium. Therefore, the program recorded in this recording medium is recorded. By reading the above into a computer system and executing it, the same effect as that obtained by the invention described in claim 5 can be obtained.

A twelfth aspect of the present invention provides a computer-readable recording medium in which a program for realizing the function of the wireless communication apparatus according to the sixth aspect is recorded.

According to the twelfth aspect of the present invention, the program for realizing the function of the wireless communication device is recorded in a computer-readable recording medium. Therefore, the program recorded in this recording medium is recorded. By loading and executing the above, the same effect as that obtained by the invention described in claim 6 can be obtained.

[0038]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 1 of the present invention
2 shows a configuration of a wireless communication device according to the embodiment. In the figure, the wireless communication device according to the first embodiment of the present invention is
Antenna 10 and QPSK received from the antenna 10
(Quadrature Phase Shift Keying) A voltage-controlled oscillator (VCO) 12 that generates a carrier wave reference signal for converting a modulated reception signal into a baseband signal, a multiplier 14, and an output of the multiplier 14 is analog / digital. It has an A / D converter 16 for converting, and a quadrature demodulator 18 for quadrature demodulating the A / D-converted baseband signal into an in-phase component (I) and a quadrature component (Q).

Further, the radio communication apparatus according to the first embodiment of the present invention oversamples the output of the quadrature demodulator and outputs phase difference data in a time interval shorter than the symbol interval over a time period in which several symbols are input. An oversampling phase difference detecting section 22 for detecting, a phase difference average calculating section 24 for calculating an average of the phase difference data output from the oversampling phase difference detecting section 22, and a voltage control output from the phase difference average calculating section 24. Frequency / voltage converter 26 for converting the frequency error data for the received signal of the carrier wave reference signal of type oscillator 12 into a voltage value, and D / for converting the output signal of frequency / voltage converter 26 into a digital / analog signal.
A converter 28.

Oversampling phase difference detector 22, phase difference average calculator 24, frequency / voltage converter 26 and D /
The A converter 28 constitutes the frequency synchronization control means 20. The frequency synchronization control means 20 is a reference for performing frequency synchronization with the received signal by using an average value over a time period in which several symbols or more or two symbols or more of phase difference data of the received signal in a time interval shorter than the symbol interval are input. The frequency of the voltage-controlled oscillator 12, which is a signal, is corrected so that it falls within a predetermined frequency error range with respect to the received signal. The frequency synchronization control means 20 corresponds to the frequency synchronization control means of the present invention.

Further, the radio communication apparatus according to the first embodiment of the present invention has a phase compensation control means 30 for controlling the phase compensation of the demodulation output of the quadrature demodulator 18 with high accuracy. The phase compensation control means 30 includes a transversal filter 32 as an adaptive phase control filter, a phase determiner 34 for determining the phase space to which the demodulated symbol data belongs based on the output of the transversal filter 32, and a phase determiner 34. From the judgment output of the transversal filter 32
And an adaptive control algorithm arithmetic processing unit 38 that determines the tap coefficient of the transversal filter 32 so as to minimize the phase error data output from the subtractor 36. The phase compensation control means 30 constitutes a Fractionally Spaced Equalizer that does not require a training signal when performing phase compensation control.

The adaptive control algorithm used in the adaptive control algorithm operation processing unit 38 is the LM in this embodiment.
S (Least Mean Squares) algorithm, but not limited to this, other adaptive control algorithms such as RL
It may be an S (Recursive Least Squares) algorithm.

Further, the radio communication apparatus according to the first embodiment of the present invention takes in the arithmetic output of the phase difference average arithmetic unit 24, and as a result of the frequency synchronization control by the frequency synchronization control means 20, the output of the voltage controlled oscillator 12. The frequency error of the reference signal which is a signal with respect to the received signal is the phase compensation control means 30.
It has a frequency error determiner 40 for determining whether or not it falls within a predetermined range in which phase compensation can be performed by adaptive phase control by. Here, "the frequency error is the phase compensation control means 30.
Within a predetermined range where phase compensation is possible by adaptive phase control by
In the embodiment of the present invention, is π for one period in phase conversion.
It shall be within / 4.

In the phase compensation control means 30, as a result of the frequency synchronization control by the frequency synchronization control means 20 by the frequency error determiner 40, the frequency error with respect to the received signal of the reference signal which is the output signal of the voltage controlled oscillator 12 is phase compensated. When it is determined by the adaptive phase control by the control unit 30 that the phase compensation is within the predetermined range, the frequency error determiner 4
Based on the determination output of 0, the phase compensation control means 30 performs adaptive phase control on the demodulation output of the quadrature demodulator 18. The response speed of the frequency correction control by the frequency synchronization control means 20 is set to be slower than the response speed of the adaptive phase control by the phase compensation control means 30. With this configuration, the control loop formed by the frequency synchronization control means 20 can have a narrow band.

The operation of the radio communication apparatus according to the embodiment of the present invention having the above configuration will be described with reference to FIGS. 2 to 6. 2 and 3 show the control operation of the frequency synchronization control means 20, and FIG. 4 shows the control operation of the phase compensation control means 30. First, when a desired reception signal is received by the antenna 10, the reception signal is received by the multiplier 14 as a carrier reference signal (frequency f
c) is multiplied and converted to a baseband signal. This baseband signal is A / D converted by the A / D converter 16 and input to the quadrature demodulator 18. The baseband signal converted into digital data is quadrature demodulated by the quadrature demodulator 18 into an in-phase component (I component) and a quadrature component (Q component).

Next, the frequency synchronization control by the frequency synchronization control means 20 shown in FIGS. 2 and 3 is performed. In these figures, in step 100, the demodulation output x (i) fetched from the quadrature demodulator 18 is oversampled by the oversampling phase difference detector 22 to detect the phase difference data at a time interval shorter than the symbol interval. . The demodulation output x (i) is represented by the following equation (1), where rk is the amplitude, φ is the phase of the modulated signal, Δfk is the frequency fluctuation amount, and T is the sampling interval.

[0047]

[Equation 1] Next, the phase difference average calculator 24 calculates the phase difference average value Δθk by the following equation (2).

[Equation 2] Here, M is the number of oversamplings, N is the number of data used for the average value calculation, and an is the transfer function after filtering.

In step 102, the value of the oversampling number M in the equation (2) is fixed to a constant value. Next, the phase difference average calculation unit 24 calculates the phase difference average value Δθk over the time when the demodulated output is input for only a few symbols by the equation (2) (step 104). The frequency fluctuation amount at the phase difference average value Δθk calculated in step 104, that is, the frequency error Δf, is converted into a voltage value by the frequency / voltage converter 26, and the voltage controlled oscillator is supplied via the D / A converter 28. 12 is applied. As a result, the frequency of the carrier wave reference signal output from the voltage controlled oscillator 12 is corrected so as to cancel the frequency error Δf (step 10).
6).

Next, at step 108, the variance V of the phase difference average value Δθk calculated so far at step 104 is calculated, and at the next step 110, it is determined whether the variance V is equal to or greater than the set value j. This determination is based on whether the control loop forming the frequency synchronization control means 20 is in a stable state. If V ≧ j, that is, if it is determined that the control loop is unstable, the number of data N in the equation (2) is incremented by +1 in the next step 112, the process returns to step 104, and steps 104 to 108 are performed. The process of is repeated. This is because data bias or phase noise is large and the control loop is in an unstable state. Therefore, by increasing the number of data N, appearance of data and noise are averaged to shift the control loop to a stable state. To control.

If it is determined in step 110 that V <j, it is determined in step 114 whether V≤k (j> k), that is, the control loop has left the unstable state,
It is determined whether or not the state has transitioned to a sufficiently stable state. k
Is the value of the variance V of the phase difference average value Δθk when the control loop is in a sufficiently stable state. If it is determined in step 114 that V ≦ k, step 1
At 15, it is determined whether N> α (α is an arbitrary integer). This determination is for avoiding this because the value of the phase difference average value Δθk diverges when N = 0 by the processing of step 116. If N> α, the process proceeds to step 116, and if N ≦ α, the process proceeds to step 104. N in step 115
If it is determined that> α, the number of data N in equation (2) is decremented by -1 in step 116, the process returns to step 104, and the processes of steps 104 to 108 are repeated. This is because when the number of data N increases, the randomness increases and the appearance probabilities of the data become equal, so the frequency error decreases, but the convergence time of the control system increases, so the number of data N is controlled to be small. To do.

On the other hand, if it is determined in step 114 that k <V <j, that is, if it is determined that the control loop is not sufficient, but it has transitioned to an appropriately stable state, step 118 in FIG. Processing shifts to. In step 118, the value of the number of data N in the equation (2) is fixed to a constant value, and in the next step 120, the phase difference average value Δθk
The absolute value | Δθk | of is compared with a threshold value. Here, the threshold value ΔθTH is set to ΔθTH> π / 4M. When it is determined in step 120 that | Δθk | ≧ ΔθTH, the oversampling number M in the equation (2) is increased (step 122) and the process proceeds to step 124.

In step 120, | Δθk | <ΔθTH
If it is determined that the oversampling number M is M> 2, it is determined at step 127. If it is determined that M> 2 at step 127, the oversampling number is over at step 128. After the number of samplings M is reduced to M / 2, and when it is determined that M ≦ 2, the process directly proceeds to step 130. Where the phase difference average value Δ
The absolute value | Δθk | of θk increases or decreases the value of the oversampling number M by comparing with the threshold because the phase difference average value Δθk, that is, the frequency error detection accuracy decreases as the frequency error Δf decreases. This is because the value of the oversampling number M is changed according to the calculation result of the left side of the equation (2) to prevent the detection accuracy from decreasing. The increase / decrease in the value of the oversampling number M corresponds to the increase / decrease in the sampling time. As described above, in the first embodiment of the present invention, the increase / decrease of the data number N (corresponding to the sampling number) and the oversampling number M (corresponding to the sampling time) is adaptively controlled according to the magnitude of the frequency error. Therefore, the accuracy of detecting the frequency error can be improved.

After the oversampling number M in the equation (2) is increased in step 122, steps 104, 10 are executed.
Similar to step 6, the phase difference average value Δθk is calculated in step 124, and the frequency of the carrier wave reference signal in the voltage controlled oscillator 12 is corrected and controlled based on the calculated phase difference average value Δθk (step 126). After the processing of step 126 or step 128, in step 130 it is determined whether or not | Δθk | ≦ π / 4, that is, the frequency synchronization control means 20 performs the frequency synchronization control and the phase compensation control means 30 performs the adaptive phase control to perform the phase compensation. The frequency error determiner 40 determines whether the frequency error Δf, that is, the phase difference average value | Δθk |

When it is determined in step 130 that | Δθk | ≧ π / 4, the process returns to step 120 and the processes of steps 120 to 130 are repeated. Step 130
When it is determined that | Δθk | ≦ π / 4, the processing shifts to the adaptive phase control by the phase compensation control means 30 based on the determination output of the frequency error determiner 40 (step 132). Here, when the frequency synchronization control means 20 detects that the frequency error of the received signal with respect to the reference carrier signal of the voltage controlled oscillator 12 is within a predetermined range (within π / 4 in terms of phase), Communication to the transmission side may be started based on the frequency. With this configuration, the phase compensation of the received signal can be performed with high accuracy on the transmitting side.

When the frequency error detecting means 20 detects that the frequency error is within the predetermined range, the receiving operation is performed, the receiving operation is temporarily stopped, and then the receiving operation is started again. Using the frequency of the reference signal, the frequency synchronization control means 20 performs frequency synchronization control so that the frequency error of the received signal with respect to the reference signal is within a predetermined range, and after stopping the reception,
When the reception is started again, the frequency of the reference signal used in the previous reception operation may be used in the current reception operation. With this configuration, it is possible to shorten the update interval of the frequency of the reference signal used for frequency synchronization control, so that even if the ambient temperature of the wireless communication device changes due to changes in the ambient environment or self-heating, the reference The time required for frequency synchronization control of signals can be shortened.

Next, the adaptive phase control by the phase compensation control means 30 will be described. In step 200 of FIG. 4, the demodulation output x (i) of the quadrature demodulator 18 is input to the transversal filter 32 that constitutes the phase compensation control means 30. Next, the adaptive control algorithm arithmetic processing unit 38
Phase compensation of the demodulation output x (i) is performed with the filter characteristic determined by the filter coefficient set by (step 202). That is, the transversal filter 3
When the filter characteristic of 2 is w (i) and the output of the transversal filter 32 is d (i), the output of the transversal filter 32 is

[Equation 3] It is represented by.

Here, the demodulation output x (i) is expressed as x (i) = ex
p {j (ak + 2πΔfT)}, the phase component due to modulation is e
xp (jak), the phase error of the demodulation output is e (i) = ex
If p (j2πΔfT), then if the filter characteristic of the transversal filter 32 is set to w (i) = exp (−j2πΔfT) by the adaptive control algorithm arithmetic processing unit 38, d (i) of the transversal filter 32 will be described.
Is

[Equation 4] , The phase error e (i) is completely eliminated and the original signal e
Only xp (jak) is extracted.

In this case, the transversal filter 32
The phase difference data Δθk, which is the difference between the adjacent phase data of the phase sequence {θk} obtained by the above, is obtained by demodulating the reception signal modulated by the four-phase QPSK modulation as shown in FIG. In the Cartesian coordinate system of
θk (k = 1 to 4) = π / 4 (first quadrant), 3π / 4 (second quadrant), −3π / 4 (third quadrant), −π / 4 (fourth quadrant)
Therefore, the symbol data specified by the demodulated dibit matches the reference data D1, D2, D3, D4 in any quadrant in the IQ coordinate system.

However, in practice, the phase error is not completely eliminated by the transversal filter 32, and the output d (i) of the transversal filter 32 has an error e.
(I) is included. In step 204, the phase determiner 34 determines the quadrant in the orthogonal coordinate system of the IQ axes to which the phase difference data obtained from the output d (i) of the transversal filter 32 belongs in the phase space. The phase determiner 34 determines that the input phase difference data Δθk is I−
It is determined which quadrant the Q orthogonal coordinate system belongs to, and the reference data of the quadrant to which the phase difference data Δθk belongs is output as being in agreement with the input symbol data (step 206). The output of the phase determiner 34 is z (i).

Next, at step 208, the phase error e (i) is calculated by the subtractor 36 by the following equation (5).

[Equation 5] Next, the adaptive control algorithm arithmetic processing unit 38 takes in the phase error e (i) and performs arithmetic processing based on the LMS algorithm, and the filter coefficient of the transversal filter 32 is minimized so that the phase error e (i) is minimized. Is determined and set in the transversal filter 32 (steps 210 and 212).

As a result, the phase error e (i) is highly accurately phase compensated within π / 4 in absolute value as shown in FIG. FIG. 6 shows frequency error characteristics, where the horizontal axis represents frequency error ΔfT and the vertical axis represents bit error rate (BER). In the figure, a curve C1 is the phase compensation control means 30.
The frequency error characteristic obtained as a result of the phase compensation by means of is shown, and the curve Cn shows the frequency error range (phase error range) in which the phase compensation control means 30 can perform phase compensation.
In the figure, when the frequency error ΔfT is ΔfT = 0.125, the phase error is π / 4.

According to the first embodiment of the present invention, QP
In a wireless communication device that uses SK modulation to perform frequency synchronization based on phase difference data of a received signal in a time interval shorter than a symbol interval, frequency synchronization control means inputs several symbols or more or two symbols or more of the phase difference data. Since the frequency of the reference signal for frequency synchronization is corrected by using the average value over time, without using an oscillator for high-precision frequency synchronization,
Frequency synchronization can be performed even when a phase rotation of π / 4 or more occurs at one cycle interval.

Further, according to the first embodiment of the present invention,
The frequency of the reference signal for performing frequency synchronization with the received signal is determined with respect to the received signal using an average value over a time period in which several symbols of phase difference data of the received signal are input by the frequency synchronization control means. By performing correction so that it falls within the frequency error range of, the frequency synchronization is performed within the frequency error range in which the phase can be compensated by the adaptive phase control, and when the frequency synchronization is achieved, the phase compensation control means adapts the demodulated signal of the received signal. Since the phase is controlled, the frequency synchronization error due to the frequency offset can be reduced.

Furthermore, since the loop for frequency synchronization can be made a narrow band, phase jitter will not occur. As a result, the phase compensation control means operates stably and high-precision phase control becomes possible. Therefore, the reliability of the demodulated data can be improved.

According to the first embodiment of the present invention, the frequency synchronization control is performed by combining the frequency correction control of the reference signal by the frequency synchronization control means and the adaptive phase control of the received signal by the Fractionally Spaced Equalizer as the phase compensation means. Since this is performed, it is possible to perform highly accurate frequency synchronization control that does not require a training signal. Although the QPSK modulation is used as the digital modulation method in the first embodiment of the present invention, the present invention is not limited to this modulation method and, for example, the DPSK modulation method and the QAM modulation method are also used. The respective effects according to the first embodiment are similarly obtained.

FIG. 7 shows the configuration of the main part of the radio communication apparatus according to the second embodiment of the present invention. The configuration of the wireless communication device according to the embodiment of the present invention differs from that of the wireless communication device according to the first embodiment shown in FIG. 1 in the output of the frequency / voltage converter 26 of the frequency synchronization control means 20. The phase error e which is the output of the subtractor 36 which constitutes the phase compensation control means 30.
Correct by adding (i) by the adder 50,
The corrected control data for the frequency synchronization control is used as the control signal of the voltage controlled oscillator 12, and the other configurations are the same, so that the duplicated description will be omitted.

According to the second embodiment of the present invention, in addition to the effect obtained by the radio communication apparatus according to the first embodiment of the present invention, frequency synchronization is provided as compared with the first embodiment. The effect is that the necessary phase compensation can be performed with higher accuracy. In the wireless communication device according to the second embodiment, the frequency to the carrier wave reference signal of the voltage controlled oscillator may be set by the corrected control data, and then the communication to the transmission side may be started. With this configuration, the phase compensation of the received signal can be performed with high accuracy on the transmitting side.

In the radio communication apparatus according to the second embodiment, the frequency of the carrier wave reference signal of the voltage controlled oscillator set by the corrected control data may be used at the next reception. With this configuration, the phase of the received signal can be compensated with high accuracy at the next reception. In the second embodiment of the present invention as well, QPSK modulation is used as the digital modulation method as in the first embodiment of the present invention, but the present invention is not limited to this modulation method, and for example DPSK modulation method, QAM Even if the modulation method is used, each effect according to the second embodiment of the present invention described above can be obtained similarly.

Next, FIG. 8 shows the configuration of a wireless communication system to which the present invention is applied. In the figure, service area 30
0 consists of a plurality of zones Z1, Z2, Z3, and within each zone, communication is performed between the base station and the mobile station using two frequencies, upstream and downstream. Each zone Z1, Z2, Z3
Then, each base station communicates using different frequencies f1, f2, f3. In this wireless communication system, each zone Z
This is a two-frequency simplex system in which each base station continuously transmits a signal to a mobile station within 1, Z2, and Z3, and the mobile station communicates by a burst signal. In this wireless communication system, any or all of the embodiments of the invention described so far are applied.

According to this wireless communication system, frequency synchronization can be performed even if a phase rotation of π / 4 or more occurs at one cycle interval without using a highly accurate frequency synchronization oscillator. Therefore, it is possible to realize a wireless communication device and a wireless communication system capable of performing highly accurate phase correction.

Further, in a radio communication apparatus which uses PSK modulation to perform frequency synchronization based on phase difference data of a received signal in a time interval shorter than a symbol interval, several symbols or more or two symbols or more of the phase difference data are input. A computer readable recording program for realizing the function of the wireless communication device, characterized by having frequency synchronization control means for correcting the frequency of the reference signal for frequency synchronization using the average value over time. The frequency synchronization control may be performed by recording the program on a medium and reading the program recorded on the recording medium into a computer system and executing the program. In this case, a program for realizing the frequency synchronization control is recorded in a computer-readable recording medium. Therefore, by reading the program recorded in the recording medium into a computer system and executing the program, a high-accuracy frequency can be obtained. It is possible to perform frequency synchronization without using an oscillator for synchronization even if a phase rotation of π / 4 or more occurs at intervals of one cycle.

Further, in a radio communication apparatus which uses DPSK modulation and performs frequency synchronization based on phase difference data of a received signal in a time interval shorter than a symbol interval, several symbols or more or two symbols or more of the phase difference data are input. A computer-readable recording medium having a program for realizing the function of a wireless communication device, characterized by having frequency synchronization control means for correcting the frequency of a reference signal for frequency synchronization using an average value over time. Alternatively, the frequency synchronization control may be performed by reading the program recorded on the computer, reading the program recorded on the recording medium into a computer system, and executing the program.

In this case, since the program for realizing the frequency synchronization control is recorded in the computer-readable recording medium, the program recorded in this recording medium is read by the computer system and executed to realize a high-performance program. It is possible to perform frequency synchronization even when a phase rotation of π / 4 or more occurs at one cycle interval without using an accurate frequency synchronization oscillator.

Further, in a radio communication apparatus which uses QAM modulation and performs frequency synchronization based on phase difference data of a received signal in a time interval shorter than a symbol interval, several symbols or more or two symbols or more of the phase difference data are input. A computer-readable recording medium having a program for realizing the function of a wireless communication device, characterized by having frequency synchronization control means for correcting the frequency of a reference signal for frequency synchronization using an average value over time. Alternatively, the frequency synchronization control may be performed by reading the program recorded on the computer, reading the program recorded on the recording medium into a computer system, and executing the program.

In this case, since the program for realizing the frequency synchronization control is recorded on the computer-readable recording medium, the program recorded on this recording medium is read by the computer system and executed to realize a high-performance program. It is possible to perform frequency synchronization even when a phase rotation of π / 4 or more occurs at one cycle interval without using an accurate frequency synchronization oscillator.

Further, in a radio communication apparatus which uses PSK modulation to perform frequency synchronization based on phase difference data of a received signal in a time interval shorter than a symbol interval, several symbols or more or two symbols or more of the phase difference data are input. Frequency synchronization control means for correcting the frequency of the reference signal for performing frequency synchronization with the received signal using an average value over time so that the frequency falls within a predetermined frequency error range with respect to the received signal; Phase compensation control means for adaptively controlling the phase of the received signal when the frequency is synchronized so that the frequency error of the reference signal with respect to the received signal falls within a predetermined range by frequency control by the means. The program for realizing the control function of the wireless communication device is recorded on a computer-readable recording medium. The frequency synchronization control and the phase compensation control may be performed by recording the program and causing the computer system to read and execute the program recorded in the recording medium.

In this case, since the program for realizing the control function of the wireless communication device is recorded on the computer-readable recording medium, the program recorded on the recording medium is read by the computer system,
By executing it, the frequency synchronization error due to the frequency offset can be reduced.

Further, since the loop for frequency synchronization can be set to a narrow band, phase jitter will not occur. As a result, the phase compensation control means operates stably and high-precision phase control becomes possible. Therefore, the reliability of the demodulated data can be improved. Further, in a wireless communication apparatus that uses DPSK modulation and performs frequency synchronization based on phase difference data of a received signal in a time interval shorter than a symbol interval, an average over a time period in which several symbols or more or two symbols or more of the phase difference data are input. Frequency synchronization control means for correcting the frequency of the reference signal for performing frequency synchronization with the received signal by using the value so that the frequency falls within a predetermined frequency error range with respect to the received signal, and the frequency by the frequency synchronization control means. Radio communication comprising: phase compensation control means for adaptively controlling the phase of the received signal when the frequency error of the reference signal with respect to the received signal is controlled so that the frequency error is within a predetermined range. A program for realizing the device control function is recorded in a computer-readable recording medium, and The program recorded in a recording medium to read into the computer system by executing, may perform frequency synchronization control and phase compensation control.

In this case, since the program for realizing the control function of the wireless communication device is recorded in the computer-readable recording medium, the program recorded in the recording medium is read by the computer system,
By executing it, the frequency synchronization error due to the frequency offset can be reduced.

Further, since the loop for frequency synchronization can be made a narrow band, phase jitter will not occur. As a result, the phase compensation control means operates stably and high-precision phase control becomes possible. Therefore, the reliability of the demodulated data can be improved.

Further, in a radio communication apparatus which uses QAM modulation and performs frequency synchronization based on phase difference data of a received signal in a time interval shorter than a symbol interval, several symbols or more or two symbols or more of the phase difference data are input. Frequency synchronization control means for correcting the frequency of the reference signal for frequency synchronization with the received signal so as to fall within a predetermined frequency error range with respect to the received signal using an average value over time, and the frequency synchronization control. Phase compensation control means for adaptively controlling the phase of the received signal when the frequency is synchronized so that the frequency error of the reference signal with respect to the received signal falls within a predetermined range by frequency control by the means. The program for realizing the control function of the wireless communication device is recorded on a computer-readable recording medium. To, to read the program recorded in this recording medium into a computer system, by executing, may perform frequency synchronization control and phase compensation control.

In this case, since the program for realizing the control function of the wireless communication device is recorded in the computer-readable recording medium, the program recorded in the recording medium is read by the computer system,
By executing it, the frequency synchronization error due to the frequency offset can be reduced.

Further, since the loop for frequency synchronization can be set to a narrow band, phase jitter will not occur. As a result, the phase compensation control means operates stably and high-precision phase control becomes possible. Therefore, the reliability of the demodulated data can be improved.

The phase compensating means is Fractionally S
A program for realizing the control function of the wireless communication device characterized by being a paced equalizer is recorded in a computer-readable recording medium, and the program recorded in this recording medium is read into a computer system and executed. By doing so, frequency synchronization control and phase compensation control may be performed.

In this case, since the program for realizing the control function of the wireless communication device is recorded in the computer-readable recording medium, the program recorded in the recording medium is read by the computer system,
By executing, the frequency correction control function of the reference signal by the frequency synchronization control means and the Fracti as the phase compensation means
Frequency synchronization control can be performed in combination with the adaptive phase control function of the received signal by the onally Spaced Equalizer, which enables highly accurate frequency synchronization control that does not require a training signal.

In order to realize the control function of the radio communication device, the response speed of the frequency correction control by the frequency synchronization control means is made slower than the response speed of the adaptive phase control by the phase compensation control means. The program may be recorded in a computer-readable recording medium, and the program recorded in the recording medium may be read and executed by a computer system to perform frequency synchronization control and phase compensation control.

In this case, since the program for realizing the control function of the wireless communication device is recorded in the computer-readable recording medium, the program recorded in the recording medium is read by the computer system,
By executing the frequency synchronization control means, which constitutes a control loop for frequency synchronization, can be narrowed.

The frequency synchronization control means adaptively controls the number of samplings of the phase difference data and the increase / decrease of the sampling time, which are the objects of the average value calculation, according to the magnitude of the frequency error. A program for realizing the control function of the wireless communication device is recorded in a computer-readable recording medium, and the program recorded in the recording medium is read into a computer system and executed to perform frequency synchronization control and phase control. Compensation control may be performed.

In this case, since the program for realizing the control function of the wireless communication device is recorded in the computer-readable recording medium, the program recorded in the recording medium is read by the computer system,
By executing this, the accuracy of detecting the frequency error can be improved.

Further, as a result of the frequency correction of the reference signal, there is provided a frequency error detecting means for detecting whether or not the frequency error of the received signal with respect to the reference signal is within a predetermined range. A program for realizing a control function of a wireless communication device, characterized in that, when a state in which the frequency error is within a predetermined range is detected, communication to the transmitting side is started based on the frequency at that time. By recording on a computer-readable recording medium,
Communication control may be performed by causing a computer system to read and execute the program recorded in this recording medium.

In this case, since the program for realizing the control function of the wireless communication device is recorded in the computer-readable recording medium, the program recorded in the recording medium is read by the computer system,
By executing this, it is possible to reduce the need for frequency synchronization acquisition on the transmission side.

The control data for controlling the frequency of the reference signal corresponding to the frequency correction amount for frequency synchronization obtained by the frequency correction control by the frequency synchronization control means is obtained by the adaptive phase control by the phase compensation control means. A control function of a wireless communication device, characterized in that the frequency is corrected by a correction value according to the amount of phase compensation, and the frequency of the reference signal is set by the corrected control data, and then communication to the transmission side is started. The communication control may be performed by recording a program for realizing the above in a computer-readable recording medium, and causing the computer system to read and execute the program recorded in the recording medium.

In this case, since the program for realizing the control function of the wireless communication device is recorded in the computer-readable recording medium, the program recorded in the recording medium is read by the computer system,
By executing this, phase compensation of the reception signal can be performed with high accuracy on the transmission side.

The receiving operation is performed under the condition that the frequency error detecting means detects that the frequency error is within the predetermined range, the receiving operation is once stopped, and then the receiving operation is started again. Using the frequency of the reference signal, the frequency synchronization control means performs frequency synchronization control so that the frequency error of the received signal with respect to the reference signal falls within a predetermined range, and after that, after stopping the reception,
When the reception is restarted, the frequency of the reference signal used in the previous reception operation is used in the current reception operation, and the program for realizing the control function of the wireless communication device is readable by a computer. Communication control may be performed by recording the program on a medium and causing the computer system to read and execute the program recorded on the recording medium.

In this case, since the program for realizing the control function of the wireless communication device is recorded in the computer-readable recording medium, the program recorded in the recording medium is read by the computer system,
By executing this, the time required for frequency synchronization control of the reference signal can be shortened even if the ambient temperature of the wireless communication device changes due to changes in the surrounding environment or self-heating.

The control data for controlling the frequency of the reference signal corresponding to the frequency correction amount for frequency synchronization obtained by the frequency correction control by the frequency synchronization control means is obtained by the adaptive phase control by the phase compensation control means. In order to realize the control function of the wireless communication device, the frequency of the reference signal set by the corrected control data is used for the next reception. The program may be recorded in a computer-readable recording medium, and the communication control may be performed by causing the computer system to read and execute the program recorded in the recording medium.

In this case, since the program for realizing the control function of the wireless communication device is recorded in the computer-readable recording medium, the program recorded in the recording medium is read by the computer system,
By executing this, phase compensation of the received signal can be executed with high accuracy at the next reception.

A two-frequency simplex wireless communication system in which a base station continuously transmits signals and a mobile station sends burst signals to communicate between the base station and a plurality of mobile stations, Both base station and mobile station, or
A program for realizing a control function of a wireless communication system, characterized in that one of them is configured by the wireless communication device according to any one of claims 2 to 9, is recorded in a computer-readable recording medium. Alternatively, the communication control may be performed by causing a computer system to read and execute a program recorded in this recording medium.

In this case, since the program for realizing the control function of the wireless communication device is recorded in the computer-readable recording medium, the program recorded in the recording medium is read by the computer system,
By executing this, frequency synchronization can be performed even when phase rotation of π / 4 or more occurs at one cycle interval without using a high-precision frequency synchronization oscillator, and high-precision phase correction It is possible to realize a wireless communication device and a wireless communication system capable of performing the above.

The “computer system” mentioned here includes an OS and hardware such as peripheral devices. The "computer-readable recording medium" means a flexible disk, a magneto-optical disk, an R
It refers to a storage medium such as a hard disk or the like built into a computer system, such as an OM or a CD-ROM.

Further, the "computer-readable recording medium" means a program dynamically for a short time like a communication line in the case of transmitting the program through a network such as the Internet or a communication line such as a telephone line. The one that holds the program, and the one that holds the program for a certain period of time, such as a volatile memory inside the computer system that is the server or client in that case, are also included. Further, the above program may be one for realizing some of the functions described above, and may be one that can realize the above functions in combination with a program already recorded in the computer system.

[0102]

As described above, according to the first aspect of the invention, according to the first aspect of the invention, digital phase modulation (PSK) is used and reception is performed at a time interval shorter than the symbol interval. In a wireless communication device that performs frequency synchronization based on phase difference data of signals, frequency synchronization is performed by using an average value over a time period in which several symbols or two symbols of the phase difference data are input by the frequency synchronization control means. Since the frequency of the reference signal is corrected, frequency synchronization can be performed even if a phase rotation of π / 4 or more occurs at one cycle interval without using a highly accurate frequency synchronization oscillator. You can Further, the frequency synchronization control means adaptively controls the increase and decrease of the sampling number and sampling time of the phase difference data to be the target of the average value calculation according to the magnitude of the frequency error. The detection accuracy can be improved.

Further, as a result of the frequency correction of the reference signal, if the frequency error detecting means detects that the frequency error of the received signal with respect to the reference signal is within the predetermined range, transmission is performed based on the frequency at that time. Since the communication to the side is started, the need for frequency synchronization acquisition on the transmitting side can be reduced.

According to the second aspect of the present invention, the differential phase modulation (DPSK) is used, and the frequency between the mobile station and the base station is based on the phase difference data of the received signal in the time interval shorter than the symbol interval. In a communication control method of a wireless communication system for performing synchronization, a frequency of a reference signal for performing frequency synchronization is corrected by using an average value over a time period in which several symbols or two symbols of the phase difference data are input. Therefore, frequency synchronization can be performed even if a phase rotation of π / 4 or more occurs at one cycle interval without using a high-precision frequency synchronization oscillator. Further, the frequency synchronization control means adaptively controls the increase and decrease of the sampling number and sampling time of the phase difference data to be the target of the average value calculation according to the magnitude of the frequency error. The detection accuracy can be improved.

Furthermore, as a result of the frequency correction of the reference signal, if the frequency error detecting means detects that the frequency error of the received signal with respect to the reference signal is within the predetermined range, transmission is performed based on the frequency at that time. Since the communication to the side is started, the need for frequency synchronization acquisition on the transmitting side can be reduced.

According to the invention described in claim 3, in the radio communication device which uses the quadrature amplitude modulation (QAM) modulation and performs frequency synchronization based on the phase difference data of the received signal in the time interval shorter than the symbol interval, Since the synchronization control means corrects the frequency of the reference signal for frequency synchronization by using the average value over the time when several symbols or more or two symbols of the phase difference data are input, the frequency synchronization with high accuracy is performed. It is possible to perform frequency synchronization even if a phase rotation of π / 4 or more occurs at one cycle interval without using an oscillator for. Further, the frequency synchronization control means adaptively controls the increase and decrease of the sampling number and sampling time of the phase difference data to be the target of the average value calculation according to the magnitude of the frequency error. The detection accuracy can be improved.

Furthermore, as a result of frequency correction of the reference signal, if the frequency error detecting means detects that the frequency error of the received signal with respect to the reference signal is within the predetermined range, transmission is performed based on the frequency at that time. Since the communication to the side is started, the need for frequency synchronization acquisition on the transmitting side can be reduced.

According to the invention of claim 4, the frequency of the reference signal used for the frequency synchronization control of the radio communication device is the frequency used in the previous reception operation. In addition to the effect obtained by the invention described in any one of 3), the time required for the frequency synchronization control of the reference signal can be shortened even if the ambient temperature of the wireless communication device changes due to changes in the surrounding environment or self-heating.

According to the fifth aspect of the present invention, the control data for controlling the frequency of the reference signal corresponding to the frequency correction amount for frequency synchronization obtained by the frequency correction control by the frequency synchronization control means is set to the control data. Correction is performed with a correction value according to the amount of phase compensation obtained by the adaptive phase control by the phase compensation control means, and after setting the frequency of the reference signal by the corrected control data, communication to the transmitting side is started. Therefore, in addition to the effect obtained by the invention according to any one of claims 1 to 3, the phase compensation of the received signal can be performed with high accuracy on the transmission side.

According to the invention described in claim 6, the control data for controlling the frequency of the reference signal corresponding to the frequency correction amount for frequency synchronization obtained by the frequency correction control by the frequency synchronization control means is phase-compensated. The correction is performed with a correction value according to the phase compensation amount obtained by the adaptive phase control by the control means, and the frequency of the reference signal set by the corrected control data is used at the next reception. In addition to the effect obtained by the invention described in (1), the phase compensation of the received signal can be performed with high accuracy at the next reception.

According to the invention of claim 7, claim 7 is provided.
In a wireless communication device that uses digital phase modulation (PSK) and performs frequency synchronization based on phase difference data of a received signal in a time interval shorter than a symbol interval, several or more symbols of the phase difference data or 2 Frequency synchronization control means for correcting the frequency of the reference signal for frequency synchronization by using the average value over the time when more than symbols are input, and the frequency of the reference signal, as a result of the frequency correction of the reference signal, the frequency of the received signal with respect to the reference signal. A frequency error detection means for detecting whether or not an error is within a predetermined range, and the frequency synchronization control means increases or decreases the sampling number and sampling time of the phase difference data to be the target of the average value calculation. It is adaptively controlled according to the magnitude of the frequency error, and the frequency error is determined by the frequency error detecting means. When a state in the area is detected, a computer-readable recording medium having a program for realizing the function of the wireless communication device, which starts communication to the transmitting side based on the frequency at that time Since the program is recorded in step 1, the same effect as the effect obtained by the invention described in claim 1 can be obtained by reading the program recorded in the recording medium into the computer system and executing the program.

According to the invention described in claim 8, in the radio communication device for performing frequency synchronization based on phase difference data of a received signal in a time interval shorter than a symbol interval, using differential phase modulation (DPSK), Frequency synchronization control means for correcting the frequency of the reference signal for frequency synchronization using an average value over a time period in which several symbols or more or two symbols or more of the phase difference data are input, and a result of frequency correction of the reference signal. A frequency error detection means for detecting whether or not a frequency error of the received signal with respect to the reference signal is within a predetermined range, and the frequency synchronization control means is provided for the phase difference data to be averaged. The number of samplings and the increase or decrease of the sampling time are adaptively controlled according to the magnitude of the frequency error, and the frequency error detecting means is used. When a state in which the frequency error is within a predetermined range is detected, communication with the transmitting side is started based on the frequency at that time, and a program for realizing the function of the wireless communication device is computer Since the program is recorded on a readable recording medium, the same effect as the effect obtained by the invention according to claim 2 can be obtained by causing the computer system to read and execute the program recorded on the recording medium. To be

According to the invention described in claim 9, in a radio communication device which uses quadrature amplitude modulation (QAM) and performs frequency synchronization based on phase difference data of a received signal in a time interval shorter than a symbol interval, Frequency synchronization control means for correcting the frequency of a reference signal for frequency synchronization using an average value over a time period in which more than two symbols or more than two symbols of phase difference data are input; and a result of frequency correction of the reference signal, Frequency error detection means for detecting whether or not the frequency error of the received signal with respect to the reference signal is within a predetermined range, and the frequency synchronization control means is for sampling the phase difference data to be the target of average value calculation. The number and the increase / decrease in sampling time are adaptively controlled according to the magnitude of the frequency error, and by the frequency error detecting means. When a state in which the frequency error is within a predetermined range is detected, a computer is provided with a program for realizing the function of the wireless communication device, which starts communication to the transmitting side based on the frequency at that time. Since the program is recorded on a readable recording medium, the same effect as the effect obtained by the invention according to claim 3 can be obtained by causing the computer system to read and execute the program recorded on the recording medium. To be

According to the tenth aspect of the present invention, the program for realizing the function of the wireless communication apparatus according to the fourth aspect is recorded in a computer-readable recording medium. The same effect as the effect obtained by the invention described in claim 4 can be obtained by causing the computer system to read and execute the program recorded in.

According to the invention described in claim 11, the program for realizing the function of the wireless communication device according to claim 5 is recorded in a computer-readable recording medium. The same effect as the effect obtained by the invention described in claim 5 can be obtained by causing the computer system to read and execute the program recorded in.

According to the twelfth aspect of the present invention, the program for realizing the function of the wireless communication apparatus according to the sixth aspect is recorded in a computer-readable recording medium. The same effect as that obtained by the invention described in claim 6 can be obtained by causing the computer system to read and execute the program recorded in.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a wireless communication device according to an embodiment of the present invention.

FIG. 2 is a flowchart showing the control operation of the frequency synchronization control means in FIG.

FIG. 3 is a flowchart showing the control operation of the frequency synchronization control means in FIG.

4 is a flowchart showing the control operation of the phase compensation control means in FIG.

FIG. 5 is an explanatory diagram showing a control operation during adaptive phase control.

FIG. 6 is a characteristic diagram showing a control state of adaptive phase control.

FIG. 7 is a block diagram showing a configuration of a main part of another embodiment of the wireless communication device of the present invention.

FIG. 8 is an explanatory diagram showing a configuration of a wireless communication system to which the present invention is applied.

[Explanation of symbols]

10 antennas 12 Voltage controlled oscillator 14 Multiplier 16 A / D converter 18 Quadrature demodulator 20 Frequency synchronization control means 22 Oversampling phase difference detector 24 Phase difference averaging unit 26 Frequency / voltage converter 28 D / A converter 30 Phase compensation control means 32 transversal filter 34 Phase detector 36 Subtractor 38 Adaptive control algorithm arithmetic processing unit

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Motoki Ishikawa             1-297 Kitabukuro-cho, Saitama City, Saitama Prefecture             Mitsubishi Materials Corporation Research Institute F term (reference) 5K004 AA05 AA08 FG02 FJ03 FJ16                       JG01 JJ02

Claims (12)

[Claims] 1. Using digital phase modulation (PSK),
In a wireless communication device that performs frequency synchronization based on phase difference data of a received signal in a time interval shorter than a symbol interval, frequency synchronization is performed using an average value over a time period in which several symbols or more or two symbols or more of the phase difference data are input. Frequency synchronization control means for correcting the frequency of the reference signal for performing, and as a result of the frequency correction of the reference signal, a frequency error for detecting whether or not the frequency error of the received signal with respect to the reference signal is within a predetermined range. A detection unit, the frequency synchronization control unit adaptively controls the sampling number of the phase difference data that is the target of the average value calculation and the increase or decrease of the sampling time according to the magnitude of the frequency error, and When the frequency error detecting means detects a state in which the frequency error is within a predetermined range, the frequency at that time is detected. Radio communication apparatus characterized by initiating a communication to the transmitting side based on. 2. A radio communication device using differential phase modulation (DPSK) for frequency synchronization based on phase difference data of a received signal in a time interval shorter than a symbol interval, wherein the phase difference data is several symbols or more or 2 or more. Frequency synchronization control means for correcting the frequency of the reference signal for frequency synchronization using the average value over the time when more than symbols are input, and the frequency correction of the reference signal, the frequency of the received signal with respect to the reference signal A frequency error detecting means for detecting whether or not an error is within a predetermined range, and the frequency synchronization control means increases or decreases the sampling number and sampling time of the phase difference data to be the target of the average value calculation. The frequency error is controlled adaptively according to the magnitude of the frequency error, and the frequency error is within a predetermined range by the frequency error detecting means. The wireless communication device starts communication to the transmitting side based on the frequency at that time when the state in 1 is detected. 3. A radio communication apparatus using quadrature amplitude modulation (QAM) to perform frequency synchronization based on phase difference data of a received signal in a time interval shorter than a symbol interval, wherein the phase difference data is several symbols or more or 2 symbols. Frequency synchronization control means for correcting the frequency of the reference signal for frequency synchronization using the average value over the time when the above is input, and the frequency error of the received signal with respect to the reference signal as a result of the frequency correction of the reference signal. Has a frequency error detection means for detecting whether or not it is within a predetermined range, the frequency synchronization control means, the number of sampling of the phase difference data subject to average value calculation and increase or decrease of the sampling time the frequency The frequency error is controlled adaptively according to the magnitude of the error, and the frequency error is kept within a predetermined range by the frequency error detecting means. A wireless communication device, which starts communication to a transmitting side based on a frequency at that time when a certain state is detected. 4. When the frequency error detecting means detects a state where the frequency error is within a predetermined range, the receiving operation is performed, the receiving operation is stopped once, and then the receiving operation is started again, at that time point. Using the frequency of the reference signal in, the frequency synchronization control means performs frequency synchronization control so that the frequency error of the received signal with respect to the reference signal falls within a predetermined range, and then stops reception and then starts reception again. The radio communication apparatus according to claim 1, wherein the frequency of the reference signal used in the previous reception operation is used in the current reception operation. 5. The control data for controlling the frequency of the reference signal corresponding to the frequency correction amount for frequency synchronization obtained by the frequency correction control by the frequency synchronization control means is controlled by the adaptive phase control by the phase compensation control means. 4. The communication to the transmitting side is started after correcting with a correction value according to the obtained phase compensation amount and setting the frequency of the reference signal by the corrected control data. The wireless communication device according to any one of 1. 6. The control data for controlling the frequency of the reference signal corresponding to the frequency correction amount for frequency synchronization obtained by the frequency correction control by the frequency synchronization control means is controlled by the adaptive phase control by the phase compensation control means. The radio communication device according to claim 5, wherein the frequency is corrected by a correction value according to the obtained phase compensation amount, and the frequency of the reference signal set by the corrected control data is used at the next reception. . 7. Using digital phase modulation (PSK),
In a wireless communication device that performs frequency synchronization based on phase difference data of a received signal in a time interval shorter than a symbol interval, frequency synchronization is performed using an average value over a time period in which several symbols or more or two symbols or more of the phase difference data are input. Frequency synchronization control means for correcting the frequency of the reference signal for performing, and as a result of the frequency correction of the reference signal, a frequency error for detecting whether or not the frequency error of the received signal with respect to the reference signal is within a predetermined range. A detection unit, the frequency synchronization control unit adaptively controls the sampling number of the phase difference data that is the target of the average value calculation and the increase or decrease of the sampling time according to the magnitude of the frequency error, and When the frequency error detecting means detects a state in which the frequency error is within a predetermined range, the frequency at that time is detected. A computer-readable recording medium a program for realizing the functions of the radio communication apparatus characterized by initiating a communication to the transmitting side based on. 8. A wireless communication apparatus which uses differential phase modulation (DPSK) and performs frequency synchronization based on phase difference data of a received signal in a time interval shorter than a symbol interval. Frequency synchronization control means for correcting the frequency of the reference signal for frequency synchronization using the average value over the time when more than symbols are input, and the frequency correction of the reference signal, the frequency of the received signal with respect to the reference signal A frequency error detecting means for detecting whether or not an error is within a predetermined range, and the frequency synchronization control means increases or decreases the sampling number and sampling time of the phase difference data to be the target of the average value calculation. The frequency error is controlled adaptively according to the magnitude of the frequency error, and the frequency error is within a predetermined range by the frequency error detecting means. When a state is detected, the computer-readable recording medium recording the program for realizing the function of the wireless communication device, which starts communication to the transmitting side based on the frequency at that time. . 9. A radio communication apparatus using quadrature amplitude modulation (QAM) to perform frequency synchronization based on phase difference data of a received signal in a time interval shorter than a symbol interval, in which several symbols or more or two symbols of the phase difference data are used. Frequency synchronization control means for correcting the frequency of the reference signal for frequency synchronization using the average value over the time when the above is input, and the frequency error of the received signal with respect to the reference signal as a result of the frequency correction of the reference signal. Has a frequency error detection means for detecting whether or not it is within a predetermined range, the frequency synchronization control means, the number of sampling of the phase difference data subject to average value calculation and increase or decrease of the sampling time the frequency The frequency error is controlled adaptively according to the magnitude of the error, and the frequency error is kept within a predetermined range by the frequency error detecting means. A computer-readable recording medium recording a program for realizing a function of a wireless communication device, which starts communication to a transmitting side based on a frequency at that time when a certain state is detected. 10. A computer-readable recording medium in which a program for realizing the functions of the wireless communication device according to claim 4 is recorded. 11. A computer-readable recording medium in which a program for realizing the function of the wireless communication device according to claim 5 is recorded. 12. A computer-readable recording medium in which a program for realizing the function of the wireless communication device according to claim 6 is recorded.