JPH11266230A - Radio receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correctly perform synchronous detection, even when an AFC error is large as well as to reduce cost. SOLUTION: This radio receiver is provided with a carrier phase rotation detection circuit 110 for taking out known data cyclically inserted in data and detecting the phase rotation amount of a carrier and an interpolation synchronization detection circuit 106 for reflecting the rotation amount of a carrier phase detected, corresponding to the data part on arithmetic interpolation using a pair of the known data and estimating the transmission line of the data. Thus, since the rotation amount of the carrier phase is reflected on the arithmetic interpolation, a synchronous detection operation can be performed correctly even when an AFC remainder is large without the use of a highly accurate crystal oscillator or a D/A converter for AFC voltage generation of a high resolution.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio receiving apparatus used for an automobile telephone, a portable telephone, and the like, and more particularly, to a spread spectrum type radio receiving apparatus.

[0002]

2. Description of the Related Art A conventional spread spectrum radio receiver will be described with reference to FIG. FIG. 4 is a block diagram showing an overall configuration of a conventional spread spectrum type mobile communication device.

A signal received by a receiving antenna 101 is amplified by a low-noise amplifier 102, quasi-synchronously detected by a quadrature detection circuit 103, and frequency-converted into a baseband signal. This frequency-converted signal is separated into Ich and Qch separately by A
The signal is converted into a digital signal by the / D conversion circuit 104, and the correlation with the spread code used at the time of transmission is obtained by the correlator 105. The signal for which the correlation has been obtained is synchronously detected by the interpolation interpolation synchronous detection circuit 106, and further the error correction code is decoded by the error correction code decoding circuit 107 to demodulate the received data. The operation timing of the data correlator 105 is as follows.
It is controlled by the correlator timing control circuit 108. The voltage controlled oscillator 109 changes the reception local frequency by changing the applied voltage.

On the other hand, the output of the correlator 105 is input to the carrier phase rotation detection circuit 110,
9, the speed of the carrier phase rotation due to the error of the reception local frequency generated by 9 is obtained. The averaging circuit 111
, And is converted to an analog control voltage by the D / A conversion circuit 112, and this analog signal is input to the control voltage input terminal of the voltage controlled oscillator 109. With this control mechanism, the oscillation frequency of the voltage controlled oscillator is controlled so that the carrier phase rotation speed at the correlator output becomes minimum. As described above, the function of automatically correcting the frequency of the local oscillator of the receiving device to an appropriate value for the partner transmitting device is provided by AFC (Automatic Frequency).
cy Control).

Next, the interpolation interpolation synchronous detection circuit 106 will be described. The “interpolation synchronous detection” is that the transmission path estimation is performed using periodically inserted pilot symbols, and the transmission path estimation values of the parts other than the pilot symbols are the transmission paths of pilot symbols before and after that. This is a synchronous detection method that substitutes a value obtained by interpolating an estimated value. "Transmission path estimation" refers to estimating the instantaneous carrier phase and amplitude using pilot symbols and the like to demodulate data by synchronous detection, and "interpolation" generally represents a sample value. It is to reproduce a continuous original wave from a pulse train. In addition, “primary interpolation” refers to calculating a primary interpolation line between a transmission path estimation value of a previous pilot symbol and a transmission path estimation value of a later pilot symbol, and In the zero-order interpolation, the average of the transmission path estimation values of the pilot symbols before and after is calculated, and is uniformly applied as the transmission path estimation value of the sandwiched portion.

FIG. 5 is a diagram showing a frame format of a received signal corresponding to interpolation and synchronous detection. As shown in the figure, known symbols are periodically inserted into a transmitted data sequence. In the interpolation detection of the interpolation in the primary interpolation operation, the carrier phase of the known symbol portion is obtained, and the carrier phase of the data portion sandwiched between the known symbols is obtained by applying a primary interpolation straight line to the carrier phases of the known symbols on both sides. Performs synchronous detection.

[0007]

However, in the conventional radio receiving apparatus, when the carrier phase is rotated by 180 degrees or more due to factors such as AFC residual during a certain known symbol and the time until the next known symbol. Has 1
There is a problem that the generation of the next straight line is not performed correctly and an error occurs in the synchronous detection output of the interposed data portion. That is, the carrier phase rotation amount detected by the carrier phase rotation detection circuit 110 is 1 per known symbol insertion cycle.
If the angle is less than 80 degrees, a correct primary interpolation straight line can be generated as shown in FIG. 6A. However, if the carrier phase rotation amount exceeds 180 degrees per known symbol insertion cycle, FIG. An erroneous primary interpolation straight line like the broken line shown in FIG. This is the interpolation interpolation synchronous detection circuit 1
This is because it is impossible to detect the carrier phase rotation of 180 degrees or more with the 06 alone.

In order to cope with such an error in the synchronous detection output, it is necessary to perform high-precision AFC. If a crystal oscillator having a high-precision voltage control function is not used as an oscillator for generating a carrier frequency, In addition, a high-resolution component must be used for the D / A conversion circuit for generating the AFC voltage. As a result, there is a problem that the cost of the apparatus is increased. The present invention has been made in view of the above problems, and has as its object to provide a radio receiving apparatus capable of correctly performing synchronous detection even when the AFC error is large and reducing the cost. And

[0009]

SUMMARY OF THE INVENTION The present inventor has determined that in a radio receiving apparatus, an interpolation and synchronous detection circuit cannot detect a carrier phase rotation of 180 degrees or more, while a carrier phase rotation detection circuit can. The present inventors have found that by inputting the carrier phase rotation speed information to the interpolation interpolation synchronous detection circuit, it is possible to generate a correct primary interpolation straight line, and have accomplished the present invention.

That is, according to the present invention, in a radio receiving apparatus, carrier phase rotation speed information detected by a carrier phase rotation detection circuit is input to an interpolation interpolation synchronous detection circuit, and a known symbol portion is determined in accordance with the carrier phase rotation speed information. It is characterized in that 180 degrees are added to the carrier phase.

Another feature is that a fixed frequency oscillator is provided instead of the voltage controlled oscillator.

Another feature is that either the 0th-order interpolation or the 1st-order interpolation is selected according to the magnitude of the carrier phase rotation speed.

Thus, even if the carrier phase rotation in the known symbol insertion cycle is 180 degrees or more, it is possible to correctly generate the primary interpolation straight line for synchronous detection.

That is, the inventor of the present invention has solved the above-mentioned problems, and has also made it possible to extend the life of the battery and reduce the power consumption of the receiving device, so that the receiving device can be operated for a long time.

[0015]

According to a first aspect of the present invention, there is provided a radio receiving apparatus comprising: carrier phase rotation detecting means for extracting known data periodically inserted into data to detect a phase rotation amount of a carrier; A transmission path estimating means for estimating a transmission path of the data by reflecting the rotation amount of the carrier phase detected corresponding to the portion in an interpolation operation using a pair of known data sandwiching the data is adopted. Also,
The wireless receiving method according to claim 8, wherein the known data periodically inserted into the data is taken out, the amount of phase rotation of the carrier is detected, and the amount of rotation of the carrier phase detected corresponding to the data portion is detected. Is reflected in an interpolation operation using a pair of known data sandwiching the data, and a transmission path of the data is estimated.

According to these configurations, the amount of rotation of the carrier phase can be reflected in the interpolation calculation. Therefore, the AFC residual can be obtained without using a high-precision crystal oscillator or a D / A converter for generating a high-resolution AFC voltage. , The synchronous detection operation can be performed correctly.

According to a second aspect of the present invention, there is provided the radio receiving apparatus according to the first aspect, wherein the interpolation is performed by using a transmission path estimation value of the known data and an interpolation line that can be changed according to the rotation amount of the carrier phase. Is adopted. Further, in the wireless receiving method according to the ninth aspect, a configuration is employed in which interpolation is performed using a transmission path estimation value of known data and an interpolation straight line that can be changed according to the rotation amount of the carrier phase.

With these configurations, when performing interpolation and synchronous detection, the range for generating the primary interpolation line of the carrier phase can be extended to a range exceeding 180 degrees per known symbol insertion cycle. Even when the difference is large, correct interpolation and synchronous detection can be performed.

According to a third aspect of the present invention, in the wireless receiving apparatus according to the first or second aspect, a configuration is employed in which an oscillation frequency of an oscillator for generating a carrier frequency is fixed.

With this configuration, the voltage control function of the oscillator for generating the carrier frequency becomes unnecessary, and the AFC
Since a D / A converter is not required, cost can be reduced.

According to a fourth aspect of the present invention, in the wireless receiving apparatus of the first or second aspect, there is provided a comparing means for comparing the detected carrier phase change information with a predetermined threshold value. The transmission path estimating means employs a configuration in which a transmission path is estimated using either a primary interpolation straight line or a zero-order interpolation straight line according to the comparison result. According to a tenth aspect of the present invention, in the wireless receiving method according to the ninth aspect, the detected carrier phase change information is compared with a predetermined threshold value, and a primary threshold is determined according to the comparison result. A configuration is employed in which the transmission path is estimated using either the interpolation straight line or the zero-order interpolation straight line.

With these configurations, when the carrier phase rotation speed is smaller than the threshold value, it is possible to reduce the power consumption of the receiving apparatus by using a zero-order interpolation line with a small amount of calculation, and to reduce the carrier phase rotation speed. Is larger than the threshold value, it is possible to follow a high-speed phase change using the primary interpolation straight line. By switching and reducing the power consumption of the receiving device, the life of the battery can be extended and the receiving device can be operated for a long time.

According to a fifth aspect of the present invention, there is provided a mobile station apparatus including the wireless receiving apparatus according to any one of the first to fourth aspects. According to a sixth aspect of the present invention, there is provided a base station apparatus including the wireless receiving apparatus according to any one of the first to fourth aspects.

According to these configurations, the amount of rotation of the carrier phase can be reflected in the interpolation calculation. Therefore, the AFC residual can be obtained without using a high-precision crystal oscillator or a D / A converter for generating a high-resolution AFC voltage. Is large, the synchronous detection operation can be performed correctly, and the cost of the apparatus can be reduced.

According to a seventh aspect of the present invention, there is provided the mobile station apparatus according to the fifth aspect and the base station apparatus according to the sixth aspect, wherein wireless communication is performed between the mobile station apparatus and the base station apparatus. Is adopted.

According to this configuration, in the receiving operation, since the rotation amount of the carrier phase can be reflected in the interpolation calculation, a high-precision crystal oscillator or a D / A converter for generating an AFC voltage with high resolution is used. Even when the AFC residual is large, the synchronous detection operation can be performed correctly.

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings. Parts having the same functions as those of the conventional technique shown in FIG. 4 are denoted by the same reference numerals.

(Embodiment 1) FIG. 1 is a block diagram showing an overall configuration of a radio receiving apparatus according to Embodiment 1 of the present invention. The radio receiving apparatus according to Embodiment 1 of the present invention includes:
A configuration in which carrier phase rotation speed information is transmitted from averaging circuit 111 to interpolation interpolation synchronous detection circuit 106 is employed.

The signal received by the receiving antenna 101 is amplified by the low noise amplifier 102, quasi-synchronously detected by the quadrature detection circuit 103, and frequency-converted into a baseband signal. This frequency-converted signal is separated into Ich and Qch separately by A
The signal is converted into a digital signal by the / D conversion circuit 104, and the correlation with the spread code used at the time of transmission is obtained by the correlator 105. The signal for which the correlation has been obtained is synchronously detected by the interpolation interpolation synchronous detection circuit 106, and further the error correction code is decoded by the error correction code decoding circuit 107 to demodulate the received data. The operation timing of the data correlator 105 is as follows.
It is controlled by the correlator timing control circuit 108. The voltage controlled oscillator 109 changes the reception local frequency by changing the applied voltage.

On the other hand, the output of the correlator 105 is input to the carrier phase rotation detection circuit 110,
9, the speed of the carrier phase rotation due to the error of the reception local frequency generated by 9 is obtained. The averaging circuit 111
, And is converted to an analog control voltage by the D / A conversion circuit 112, and this analog signal is input to the control voltage input terminal of the voltage controlled oscillator 109. With this control mechanism, the oscillation frequency of the voltage controlled oscillator is controlled so that the carrier phase rotation speed at the correlator output becomes minimum.

Next, the interpolation and synchronous detection circuit 106 will be described. FIG. 5 is a diagram showing a frame format of a received signal corresponding to interpolation and synchronous detection. As shown in the figure, known symbols are periodically inserted into a transmitted data sequence. In the interpolation detection of the interpolation in the primary interpolation operation, the carrier phase of the known symbol portion is obtained, and the carrier phase of the data portion sandwiched between the known symbols is obtained by applying a primary interpolation straight line to the carrier phases of the known symbols on both sides. Performs synchronous detection.

Here, the carrier phase rotation detection circuit 110
The carrier phase rotation speed information detected in step (1) is input to the interpolation and synchronous detection circuit 106. Accordingly, when performing interpolation and synchronous detection, the interpolation and synchronous detection circuit 106 performs an operation to extend the generation range of the primary interpolation line of the carrier phase to a range exceeding 180 degrees per known symbol insertion cycle. .

In the conventional radio receiving apparatus, the carrier phase rotation amount detected by the carrier phase rotation detection circuit 110 is
If it is less than 180 degrees per known symbol insertion cycle,
As shown in FIG. 6A, a correct primary interpolation straight line can be generated. However, when the carrier phase rotation amount exceeds 180 degrees per known symbol insertion cycle, the carrier phase detected by the carrier phase rotation detection circuit 110 can be generated. When the rotation speed information is not used, an erroneous primary interpolation line such as a broken line shown in FIG. 6B has been generated. This is because it is impossible to detect a carrier phase rotation of 180 degrees or more by the interpolation interpolation synchronous detection circuit 106 alone.

On the other hand, in the radio receiving apparatus according to the first embodiment of the present invention, the carrier phase rotation speed information detected by carrier phase rotation detection circuit 110 is input to interpolation interpolation synchronous detection circuit 106. If the amount of carrier phase rotation detected by the carrier phase rotation detection circuit 110 exceeds 180 degrees per known symbol insertion cycle, 180 degrees is added to the carrier phase of the known symbol portion calculated by the interpolation interpolation synchronous detection circuit 106 I do. This makes it possible to generate a correct primary interpolation straight line.

If the carrier phase rotation amount detected by the carrier phase rotation detection circuit 110 is n times 180 degrees per known symbol insertion cycle, the known symbol portion obtained by the interpolation interpolation synchronous detection circuit 106 is used. By adding n times 180 degrees to the carrier phase, it is possible to cope with a larger carrier phase rotation amount.

Next, the operation of the AFC will be described. In the carrier phase rotation detection circuit 110, the voltage controlled oscillator 1
The speed of the carrier phase rotation due to the error in the reception local frequency generated in step 09 is obtained. Further, a time average is obtained by the averaging circuit 111, and is converted into an analog control voltage by the D / A conversion circuit 112 and is input to the control voltage input terminal of the voltage controlled oscillator 109. With this control mechanism,
The oscillation frequency of the voltage controlled oscillator 109 is controlled so that the carrier phase rotation speed at the output of the correlator 105 becomes minimum.

Next, the operation of the carrier phase rotation detection circuit 110 will be described. When the data modulation method is the QPSK modulation, the quasi-coherently detected received signal is 9
Appears at four points separated by 0 degrees. These points are rotated at an angle that is an integral multiple of 90 degrees for each data symbol, and an operation is performed so that the points always have the same angle. By performing this operation, when the frequency of the received local signal is equal to the carrier frequency of the transmitter, the signal completely overlaps one point. However, when there is an error in the received local frequency, the carrier phase rotation for each symbol time is performed. They will overlap at an angle shifted by the minute. If the angle of this shift is smaller than the change in phase due to data modulation, the phase rotation angle per symbol can be determined from the angle of this shift, and the frequency error of the received local signal can be calculated.

As described above, according to the radio receiving apparatus according to Embodiment 1 of the present invention, even if the AFC residual is large, the amount of carrier phase rotation detected by carrier phase rotation detecting circuit 110 is small. , And 180 degrees are added to the carrier phase of the known symbol according to the amount of carrier phase rotation, so that the primary interpolation straight line is properly generated without performing high-precision AFC. Therefore, it is possible to prevent a situation in which an error occurs in the synchronous detection output of the data portion. Further, since the occurrence of errors can be prevented without requiring a crystal oscillator having a high-precision voltage control function or a high-resolution D / A converter, cost can be reduced.

(Embodiment 2) Next, a radio receiving apparatus according to Embodiment 2 of the present invention will be described with reference to FIG. FIG. 2 is a block diagram showing an overall configuration of the radio receiving apparatus according to Embodiment 2 of the present invention. As shown in the figure, in the second embodiment, the fixed frequency oscillator 2 is replaced with the voltage controlled oscillator 109 in the first embodiment shown in FIG.
01 was provided. The fixed frequency oscillator 201 oscillates only at a constant frequency.
Is applicable when the oscillation frequency accuracy of the fixed frequency oscillator 201 is relatively good and the carrier phase rotation amount is suppressed within a range that can be detected by the carrier phase rotation detection circuit 110. For example, when QPSK is used for information modulation, 0, 90, 18
Since the received signal appears at the points of 0 degrees and 270 degrees, the rotation amount of the carrier phase in one symbol time changes from -45 degrees to +45 degrees.
Detection up to 45 degrees is possible. The “range that can be detected by the carrier phase rotation detection circuit 110” refers to this range.

As described above, by performing the synchronous detection by estimating the carrier phase in units of one symbol, the variation of the carrier phase due to the frequency deviation of the reception local oscillator is canceled by the interpolation interpolation synchronous detection circuit 106. As a result, the same effect as that of performing AFC is obtained, and the voltage control function such as the D / A converter 112 for AFC and the voltage control oscillator 109 becomes unnecessary, and the cost is further reduced. be able to.

(Embodiment 3) Next, a radio reception apparatus according to Embodiment 3 of the present invention will be described with reference to FIG. FIG. 3 is a block diagram showing an overall configuration of a radio receiving apparatus according to Embodiment 3 of the present invention. As shown in FIG. 3, in the third embodiment, the carrier phase rotation speed information and the predetermined threshold value are provided between interpolation interpolation synchronous detection circuit 106 and averaging circuit 111 in the first embodiment shown in FIG. Is provided with a threshold value comparison circuit 301 for comparing Other configurations are the same as those of the first embodiment.

Next, the operation of the radio receiving apparatus according to Embodiment 3 of the present invention will be described. When performing the interpolation and synchronous detection, the carrier phase rotation speed information detected by the carrier phase rotation detection circuit 110 is input to the threshold value comparison circuit 301. When the carrier phase rotation speed is smaller than a predetermined threshold value, the threshold value comparison circuit 301 detects a signal to be subjected to zero-order interpolation, which requires a small amount of calculation, together with the carrier phase rotation speed information and interpolation interpolation synchronous detection. Output to the circuit 106. On the other hand, when the carrier phase rotation speed is higher than the predetermined threshold value, 1 is set to follow a fast phase change.
A signal to be subjected to the next interpolation is output to the interpolation synchronous detection circuit 106.

As described above, according to the radio receiving apparatus according to Embodiment 3 of the present invention, it is possible to select either zero-order interpolation or first-order interpolation according to the magnitude of the carrier phase rotation speed. Therefore, when the carrier phase rotation speed is low, by performing 0-order interpolation with a small amount of calculation,
By reducing the power consumption of the receiving device, it is possible to extend the life of the battery and prolong the operating time.

[0044]

As is apparent from the above description, according to the present invention, since the rotation amount of the carrier phase can be reflected in the interpolation calculation, a high-precision crystal oscillator or a high-resolution AFC voltage generating AFC voltage generator can be used. A without using a D / A converter
Even when the FC residual is large, the synchronous detection operation can be performed correctly.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an overall configuration of a radio receiving apparatus according to Embodiment 1 of the present invention.

FIG. 2 is a block diagram showing an overall configuration of a radio receiving apparatus according to Embodiment 2 of the present invention.

FIG. 3 is a block diagram showing an overall configuration of a radio receiving apparatus according to Embodiment 3 of the present invention.

FIG. 4 is a block diagram showing the overall configuration of a conventional radio receiving apparatus.

FIG. 5 is a diagram showing a frame format in interpolation and synchronous detection.

6A is a diagram showing a primary interpolation straight line in interpolation interpolation synchronous detection when the carrier phase rotation amount is less than 180 degrees. FIG. 6B is a diagram showing interpolation interpolation synchronous detection when the carrier phase rotation amount is 180 degrees or more. Figure showing the primary interpolation straight line in

[Explanation of symbols]

 Reference Signs List 101 reception antenna 102 low noise amplifier 103 quadrature detection circuit 104 A / D conversion circuit 105 correlator 106 interpolation interpolation synchronous detection circuit 107 error correction code decoding circuit 108 correlator timing control circuit 109 voltage controlled oscillator 110 carrier phase rotation detection circuit 111 Averaging circuit 112 D / A conversion circuit 201 Fixed frequency oscillator 301 Threshold value comparison circuit

Claims (10)

[Claims] 1. A carrier phase rotation detecting means for extracting known data periodically inserted into data and detecting a carrier phase rotation amount, and detecting a carrier phase rotation amount detected corresponding to the data portion. A wireless transmission apparatus comprising: a transmission path estimating unit configured to estimate a transmission path of the data by reflecting the result in an interpolation operation using a pair of known data sandwiching the data. 2. The radio receiving apparatus according to claim 1, wherein interpolation is performed using a transmission path estimation value of the known data and an interpolation straight line that can be changed according to the rotation amount of the carrier phase. 3. The radio receiving apparatus according to claim 1, wherein the oscillation frequency of the oscillator for generating the carrier frequency is fixed. 4. A comparison means for comparing the detected carrier phase change information with a predetermined threshold value, wherein the transmission path estimating means includes a primary interpolation straight line or a zero-order interpolation according to the comparison result. 3. The radio receiving apparatus according to claim 1, wherein the transmission path is estimated using one of the straight lines. 5. A mobile station device comprising the wireless receiving device according to claim 1. 6. A base station device comprising the wireless receiving device according to claim 1. 7. The mobile station device according to claim 5, and claim 6.
A mobile radio communication system, comprising: the base station device according to claim 1; and performing wireless communication between the mobile station device and the base station device. 8. A method for extracting known data periodically inserted into data, detecting a phase rotation amount of a carrier, and determining a rotation amount of a carrier phase detected corresponding to the data portion by using a pair of data that sandwiches the data. A wireless reception method, wherein a transmission path of the data is estimated by reflecting the result in an interpolation operation using known data. 9. The radio receiving method according to claim 8, wherein the interpolation is performed using a transmission path estimation value of the known data and an interpolation straight line that can be changed according to the rotation amount of the carrier phase. 10. The detected carrier phase change information is compared with a predetermined threshold value, and according to a result of the comparison, one of a first-order interpolation line and a zero-order interpolation line is used to determine a transmission path. The radio receiving method according to claim 9, wherein the estimation is performed.