JP2001274759A - Wireless receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wireless receiver that receives a plurality of wireless frequency signals, occupying different frequency bands and arriving in parallel and flexibly compensates for level the differences caused among the individual wireless frequency signals. SOLUTION: The wireless receiver is provided with a collective demodulation means 11, that receives a wave consisting of a plurality (N) of synthesized wireless frequency signals occupying different bands, demodulates the wave while keeping the level of the received wave to a prescribed level in batch, and outputs a synthesized demodulation signal generated by synthesizing a plurality (N) of demodulation signals corresponding to the respective wireless frequency signals and each distributed in different frequency bands, with a plurality (N) of frequency conversion means 12-1 to 12-N, that output a plurality (N) of the demodulation signals included in the synthesized demodulation signal as signals each distributed to a common frequency band, and is further provided with a plurality (N) of level correction means 13-1 to 13-N, that keep the power of the signals to prescribed values with desired accuracy in parallel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit for receiving a reception wave in which a plurality of radio frequency signals arriving in different bands and arriving in parallel are synthesized and individually performing predetermined processing on these radio frequency signals. And a radio receiver for distributing in parallel.

[0002]

2. Description of the Related Art In recent years, mobile communication systems have rapidly spread due to market liberalization and competition among a plurality of telecommunications companies. Not only are e-mail and other data communication services provided.

[0003] Conventionally, in many mobile communication systems, the TDMA system has been often applied as a multiple access system. However, for next generation mobile communication systems,
A CDMA system that can provide various communication services and effectively use radio frequencies and has high confidentiality has been actively applied, and various technologies related to its practical use have been developed.

In particular, in a wideband CDMA mobile communication system, a plurality of (following, for simplicity, it is assumed to be "4") wide frequency bands allocated to individual communication carriers are used in parallel. Thus, various wireless channels are formed. Therefore, in the radio base station of such a mobile communication system, for the purpose of inexpensively and accurately realizing the reception processing related to each radio channel, at the top of the tower where the antenna is installed, the above-mentioned plurality of frequency bands are used. A process is performed to collectively implement frequency conversion, level fluctuation compensation, and demodulation on received waves received in parallel via the CDMA system.

FIG. 8 is a diagram showing a configuration example of a radio receiver adapted to the wideband CDMA system. In the figure,
A low-noise amplifier 82, a frequency converter 83, an intermediate frequency filter 84,
The GC unit 85 and the quadrature demodulator 86 are connected. The output of the quadrature demodulator 86 is connected in parallel to the inputs of the carrier extractors 87-1 to 87-4 individually corresponding to the occupied bands of a plurality (= 4) of radio frequency signals that can arrive in parallel as received waves. Connected. A local oscillator 8 is applied to the local oscillator input of the frequency converter 83.
8 are connected, and the components of the received wave individually extracted from the occupied band described above are obtained at the outputs of the carrier extraction units 87-1 to 87-4, and these components are used for signal determination, error correction, It is provided to a circuit (not shown) at a subsequent stage for performing RAKE reception and other processes.

The AGC unit 85 includes a cascaded variable gain amplifier 89 and an A / D converter (A / D) 90.
From the output of the A / D converter 90 to the variable gain amplifier 8
Gain control section 9 forming a negative feedback path across the control terminals 9
And 1. Further, the carrier extraction unit 87-1
Is composed of a cascade-connected frequency shift section 92-1 and a digital filter 93-1.

Since the configuration of the carrier extraction units 87-2 to 87-4 is the same as the configuration of the carrier extraction unit 87-1, the corresponding components are assigned "2" instead of the subscript number "1". The same reference numerals to which “−4” is added are given, and the description is omitted here. In the conventional example having such a configuration, as shown in FIG. 9 (a), a reception wave composed of four radio frequency signals which are arranged adjacent to each other at an interval of 5 MHz and individually modulated, as shown in FIG. Comes.

In the following, it is assumed that these four radio frequency signals come from one or a plurality of terminal devices used by a subscriber of a mobile communication system to which the above-described wideband CDMA system is applied. The low-noise amplifier 82 amplifies the received wave and supplies it to the frequency converter 83. The frequency converter 83 and the intermediate frequency filter 84
As shown in FIG. 9 (b), of the components given as the product of the received wave and the local oscillation signal generated by the local oscillator 88, the nominal frequency is equal to the difference f _IF between the two frequencies, and An intermediate frequency signal obtained by shifting the four occupied bands while being preserved on the frequency axis is output.

In the AGC unit 85, the variable gain amplifier 89 and the A / D converter 90 link the gain control unit 91 forming the negative feedback path as described above to keep the level of the intermediate frequency signal constant. keep. The quadrature demodulation unit 86
By orthogonally demodulating the intermediate frequency signals of which the level is kept constant in this way, two orthogonal signals are obtained.
Demodulated signals corresponding to the two channels I and Q are generated.

The frequency shift units 92-1 to 92-4 and the digital filters 93-1 to 93-4 provided in the carrier extraction units 87-1 to 87-4 respectively correspond to those shown in FIGS. as shown in (4), relatively with the corresponding radio-frequency signals on the frequency axis _{(-f IF + 7.5MHz), (} - f IF + 2.5MH
z), (−f _IF −2.5 MHz), (−f _IF −7.5 MHz), and only the components in the ± 2.5 MHz band around the origin of the frequency axis in parallel. By extracting, four baseband signals individually corresponding to these radio frequency signals are generated.

[0011] These baseband signals are respectively arranged at the subsequent stage of the carrier extraction sections 87-1 to 87-4, and have the above-described signal determination processing, error correction processing, RA processing, and the like.
It is provided in parallel to a circuit that performs KE reception processing and other processing. As described above, in the conventional example illustrated in FIG. 8, suppression of level fluctuation, quadrature demodulation, and conversion to a baseband signal of a received wave including the above-described four radio frequency signals are collectively performed near the feeding end of the antenna 81. It is done.

That is, even when the number of radio channels formed based on the CDMA system in parallel with these radio frequency signals increases or decreases over a wide range, the antenna system of the radio base station has a feed line with extremely low loss. Is surely realized without being applied.

Therefore, restrictions on the physical or geographical environment in which the radio base station is to be installed are surely alleviated, and the construction of a wideband CDMA mobile communication system can be achieved at low cost.

[0014]

By the way, in the above-mentioned conventional example, the level of each baseband signal obtained at the output of the carrier extraction units 87-1 to 87-4 (digital filters 93-1 to 93-4) Is calculated according to the number of radio channels formed in parallel based on the CDMA system and the amount of transmission information to be transmitted via the radio channel.
It increases or decreases significantly depending on the traffic or traffic distribution.

That is, the carrier extraction units 87-1 to 87-4
In the subsequent stages of signal determination, error correction, RAKE reception, and other processing performed as digital processing,
Due to such an increase or decrease in the level of the radio frequency signal, the effective dynamic range has not always been kept uniform in the digital domain. Therefore, in the conventional example, in particular, the larger the difference between the above-mentioned traffic volume and traffic between the bands of the individual radio frequency signals, the larger the traffic volume and the traffic described above, and the above-described processing to be performed on the radio frequency signal. Unnecessary rounding errors occurred in the process, and there was a high possibility that transmission quality and service quality would deteriorate.

[0016] Further, such a difference in traffic or traffic can occur in response to an accident or other event that occurs only in a specific area, regardless of how the channel arrangement or zone configuration is optimized. And it was difficult to predict and deal with. The present invention flexibly adapts to the wide range of level differences that can occur between individual RF signals without significant changes in configuration, and separates these RF signals individually and accurately in baseband into the digital domain. It is an object of the present invention to provide a wireless receiver that can convert the signal into a signal.

[0017]

FIG. 1 is a block diagram showing the configuration of a first embodiment of the present invention;
It is a principle block diagram of the invention of 5 described. The invention according to claim 1 receives a reception wave obtained by synthesizing a plurality of N radio frequency signals having different occupied bands, and demodulates them collectively while maintaining the level of the reception wave at a predetermined value. A collective demodulation means 11 for outputting a combined demodulated signal obtained by combining a plurality of N demodulated signals distributed in different bands individually corresponding to the radio frequency signal, and a plurality of demodulated signals included in the combined demodulated signal output by the collective demodulation means 1 In a radio receiver including a plurality of N frequency conversion units 12-1 to 12-N that individually output N demodulated signals as signals distributed in a common band, a plurality of N frequency conversion units 12-1 to 12-N A plurality of N level correcting means 13-1 to 13-N for keeping the power of signals individually output by -N at a prescribed value in parallel with desired accuracy are provided.

FIG. 2 is a block diagram showing the principle of the present invention. According to a second aspect of the present invention, a received wave obtained by combining a plurality of N radio frequency signals having different occupied bands is received, and the received waves are collectively demodulated while keeping the level of the received wave at a predetermined value. A collective demodulation means 11 for outputting a combined demodulated signal obtained by combining a plurality of N demodulated signals distributed in different bands individually corresponding to the radio frequency signal, and a plurality of demodulated signals included in the combined demodulated signal output by the collective demodulation means 11 N number of frequency converting means 12-1 to 12 for outputting N demodulated signals individually as signals distributed in a common band
-N, the monitoring means 21 for determining the deviation of the power distributed in the individual occupied bands of the plurality N of demodulated signals, and the monitoring means 21 for the individual occupied bands of the plurality N of demodulated signals. Captures the deviation of the power
A plurality of N level correcting means 22 for correcting these deviations in parallel at a subsequent stage of the plurality of N frequency converting means 12-1 to 12-N.
-1 to 22-N.

According to a third aspect of the present invention, in the wireless receiver according to the first aspect, the collective demodulation means 11 orthogonally demodulates the received wave and combines the demodulated signals corresponding to two mutually orthogonal channels. And the N number of frequency conversion means 12-1 to 12-N output a signal distributed in a common band as two signals corresponding to two channels orthogonal to each other, respectively. Means 13-1 ~
13-N denotes a plurality N of frequency conversion units 1 as symbolic sums or instantaneous sums of squares or averages of instantaneous values of two signals corresponding to two mutually orthogonal channels, respectively.
It is characterized in that the powers of the individually output signals are identified by 2-1 to 12-N.

According to a fourth aspect of the present invention, in the wireless receiver according to the second aspect, the monitoring means 21 controls the power of a single or a plurality of frequency components distributed in an occupied band of a plurality of N demodulated signals. It is characterized in that a deviation of power distributed in these bandwidths is obtained by performing FFT obtained by frequency thinning. According to a fifth aspect of the present invention, in the wireless receiver according to the first aspect, the plurality of N level correction units 13-1 to 13-N are configured to convert the plurality of N demodulated signals into a plurality of N frequency conversion units 12-1. 12-N to vary the coefficients to be applied to the filtering performed in the digital domain, so that the powers of the signals output individually by these frequency conversion means 12-1 to 12-N are set to a specified value. It is characterized by keeping.

According to a sixth aspect of the present invention, in the radio receiver according to the second aspect, a plurality of N level correction means 22-1 are provided.
.About.22-N is obtained by varying the absolute value of a complex coefficient to be applied to the frequency conversion processing performed in the digital domain by the plurality N of frequency conversion means 12-1 to 12-N on the plurality N of demodulated signals. The power deviations obtained by the monitoring means 21 for these demodulated signals are corrected in parallel.

In the radio receiver according to the first aspect of the present invention, the collective demodulation means 11 comprises a plurality of N demodulators having different occupied bands.
Receiving the reception wave obtained by synthesizing the radio frequency signals, demodulating them collectively while maintaining the level of the reception wave at a predetermined value, and distributing the reception waves in different bands individually corresponding to these radio frequency signals. A combined demodulated signal obtained by combining the N demodulated signals is output. A plurality N of frequency conversion means 12-1 to
12-N outputs a plurality of N demodulated signals included in the synthesized demodulated signal individually as signals distributed in a common band.
The plurality of N level correcting means 13-1 to 13-N keep the power of the signals individually output by these frequency converting means 12-1 to 12-N at a predetermined value in parallel with desired accuracy.

That is, fluctuations in the transmission characteristics of the wireless transmission path,
Due to the increase / decrease in the number of transmitting stations transmitting in parallel, the applied channel control scheme, the zone configuration, the channel arrangement, the frequency arrangement, and the like, the levels of the plurality of N radio frequency signals arriving as the above-described received waves are increased. Even when individually increasing and decreasing, the difference between these levels is stably absorbed. Therefore, the provision of the batch demodulation means 11 reduces the configuration of the antenna system, and stably maintains the transmission characteristics of the radio channels formed in the bands of the individual radio frequency signals.

In the radio receiver according to the second aspect of the present invention, the collective demodulation means 11 comprises a plurality of N different occupied bands.
Receiving the reception wave obtained by synthesizing the radio frequency signals, demodulating them collectively while maintaining the level of the reception wave at a predetermined value, and distributing the reception waves in different bands individually corresponding to these radio frequency signals. A combined demodulated signal obtained by combining the N demodulated signals is output. A plurality N of frequency conversion means 12-1 to
12-N outputs a plurality of N demodulated signals included in the synthesized demodulated signal individually as signals distributed in a common band.

Further, the monitoring means 21 calculates a deviation of the power distributed in each occupied band of the plurality of N demodulated signals. The plurality of N level correction units 22-1 to 22-N capture the power deviations obtained by the monitoring unit 21 for the individual occupied bands of these demodulated signals, and the plurality of N frequency conversion units 12-1 to 12-N. These deviations are corrected in parallel after N.

That is, fluctuations in the transmission characteristics of the radio transmission path,
Due to the increase / decrease in the number of transmitting stations transmitting in parallel, the applied channel control scheme, the zone configuration, the channel arrangement, the frequency arrangement, and the like, the levels of the plurality of N radio frequency signals arriving as the above-described received waves are increased. Even when individually increasing and decreasing, the difference between these levels is stably absorbed. Accordingly, the provision of the collective demodulation means 11 reduces the configuration of the antenna system, while maintaining the transmission characteristics of the radio channels formed in the bands of the individual radio frequency signals stably high.

In the wireless receiver according to the third aspect of the present invention, in the wireless receiver according to the first aspect, the collective demodulating means 11 orthogonally demodulates the received wave to correspond to two mutually orthogonal channels. And outputs a combined demodulated signal. The plurality N of frequency conversion means 12-1 to 12-N output signals distributed in a common band as two signals corresponding to these two channels, respectively. The plurality of N level correcting means 13-1 to 13-N are individually output by the frequency converting means 12-1 to 12-N as the sum of squares or the average of the sum of the symbol values or instantaneous values of these two signals. The power of the applied signal.

That is, a plurality of N given as received waves
The level of the radio frequency signal is reliably obtained by performing a simple arithmetic operation on the signals of the two channels given as a result of the quadrature demodulation performed by the collective demodulation means 11. Therefore, the hardware configuration can be simplified as long as the above-mentioned radio frequency signal is a signal generated based on some quadrature modulation method.

In the radio receiver according to the fourth aspect of the present invention, in the radio receiver according to the second aspect, the monitoring means 21 comprises a single or a plurality of frequencies distributed in an occupied band of a plurality N of demodulated signals. By performing FFT for obtaining the power of the component by frequency thinning, the deviation of the power distributed in these bands is obtained. That is, the levels of a plurality N of radio frequency signals arriving as received waves are collectively obtained with a desired accuracy under a simple FFT.

Therefore, the radio receiver according to the present invention can be realized without deteriorating its performance by actively applying digital signal processing. According to a fifth aspect of the present invention, in the wireless receiver according to the first aspect, a plurality of N level correcting means 13-1 are provided.
To 13-N are obtained by varying coefficients applied to filtering processing to be performed in the digital domain by the plurality of N frequency conversion means 12-1 to 12-N on the plurality N of demodulated signals.
The power of the signals individually output by these frequency conversion means 12-1 to 12-N is kept at a specified value.

That is, the difference between the levels of a plurality of N radio frequency signals arriving as received waves is determined in parallel during the filtering process to be performed in order to obtain these radio frequency signals in parallel as desired baseband signals. Absorbed. Therefore, compared to a case where such a difference in level is compressed by means provided individually, the scale of hardware is reduced and the configuration is simplified.

According to a sixth aspect of the present invention, in the wireless receiver according to the second aspect, a plurality of N
The level correction means 22-1 to 22-N of the complex coefficients to be applied to the frequency conversion processing performed in the digital domain by the plurality of N frequency conversion means 12-1 to 12-N on the plurality N of demodulated signals. By varying the absolute value, the power deviation obtained by the monitoring means 21 for these demodulated signals is corrected in parallel.

That is, the difference between the levels of the plurality of N radio frequency signals arriving as received waves is determined in parallel during the frequency conversion process to be performed to obtain these radio frequency signals in parallel as desired baseband signals. Is absorbed.
Therefore, compared to a case where such a difference in level is compressed by means provided individually, the scale of hardware is reduced and the configuration is simplified.

[0034]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 3 is a diagram showing a first embodiment of the present invention. In the figure, components having the same functions and configurations as those shown in FIG. 8 are denoted by the same reference numerals, and description thereof is omitted here.

The difference between the present embodiment and the conventional example shown in FIG. 8 lies in the structure of the carrier extracting units 31-1 to 31-4 provided in place of the carrier extracting units 87-1 to 87-4. is there. The difference between the carrier extracting unit 31-1 and the carrier extracting unit 87-1 is that the multiplier 32-11 corresponding to the two mutually orthogonal channels I and Q is provided after the digital filter 93-1. , 32-12, and these multipliers 32-1
1, a power measuring unit 33-1 cascaded to the output of 32-12,
Averaging section 34-1, comparator 35-1 having an output connected to one input and a predetermined threshold given to the other input, and comparator 35-1 And a gain controller 36-1 having an input directly connected to the output of the multiplier 32-11 and an output connected to the multiplier input of the multipliers 32-11 and 32-12.

Note that the configuration of the carrier extraction units 31-2 to 31-4 is the same as the configuration of the carrier extraction unit 31-1, and therefore, in the following, the corresponding components are assigned the subscript "1".
Are assigned the same reference numbers with “2” to “4” added thereto, and the description thereof is omitted here. Hereinafter, the operation of the present embodiment will be described.

First, the carrier extraction units 31-1 to 31-4
It is arranged in parallel after the quadrature demodulator 86 and performs the same processing in parallel. Therefore, in the following, for matters common to these carrier extraction units 31-1 to 31-4,
Instead of the suffix numbers “1” to “4”, the description will be made using a code with “C” added, which can correspond to any of these suffix numbers.

In the carrier extraction section 31-C, the gain control section 3
6-C gives the same multiplier preset as an initial value (here, it is assumed to be "1" for simplicity) to the multipliers 32-C1 and 32-C2 at the time of starting. On the other hand, these multipliers 32-C1 and 32-C2 multiply the baseband signal provided by the digital filter 93-C by the multiplier, regardless of such a multiplier, to thereby generate the baseband signal. Adjust the level.

Power measuring section 33-C includes two channels I and Q included in the baseband signal and orthogonal to each other.
(Here, for simplicity, it is assumed that they are symbol values.) By performing an arithmetic operation represented by the equation of P = i ² + q ^{2 on} i and q, the power of the baseband signal is obtained. Measure P.

The averaging section 34-C obtains the average power of the baseband signal by performing a smoothing process on the power P. The comparator 35-C is given a threshold value indicating the standard value of the average power of the baseband signal to be obtained in the state where the multiplier is “1”, and the threshold value is obtained by the averaging unit 34-C. The difference between the average power and this threshold is determined.

As described above, the gain control unit 36-1 appropriately updates the common multiplier to be given to the multipliers 32-C1 and 32-C2 in a direction in which the difference becomes "0". That is, the difference between the levels of the four radio frequency signals included in the demodulated signals provided in parallel to the carrier extraction units 31-1 to 31-4 by the quadrature demodulator 86 is determined by the multipliers 32-C1, 32-C2, Under the above-described feedback control performed by the measurement unit 33-C, the averaging unit 34-C, the comparator 35-C, and the gain control unit 36-C, compression is performed with high accuracy.

Therefore, according to the present embodiment, these four radio frequency signals are collectively orthogonally demodulated at the top of the tower to reduce the cost of the antenna system and to reduce the transmission quality that has occurred in the conventional example. And degradation of service quality is greatly or accurately reduced. In the present embodiment, in the carrier extraction units 31-1 to 31-4, the deviation of the level of each radio frequency signal is compressed based on feedback control.

However, the present invention is not limited to such a configuration. For example, deviations in the levels of individual radio frequency signals may be compressed based on feedforward control. In the present embodiment, the power measurement unit 33-C calculates the power P of the baseband signal by performing the arithmetic operation shown in the above equation. However, such power P is
For example, as shown by hatching in FIG. 4, absolute value acquisition units 41-C1 and 41-C2 individually corresponding to two channels I and Q orthogonal to each other, and these absolute value acquisition units 41-C1 and 41-C2. C
By providing an adder 42-C for taking the sum at the output end of 1, 41-C2 instead of the power measuring unit 33-C described above, the adder 42-C is calculated as an approximate value as shown by the equation of P ≒ i + q. You may.

FIG. 5 is a diagram showing a second embodiment of the present invention. In the drawing, the difference from the embodiment shown in FIG. 3 is that carrier extracting units 51-1 to 51-4 are provided instead of carrier extracting units 31-1 to 31-4, and quadrature demodulator 8
6 are connected in series to the output of
The point is that a power monitoring unit 52 having four outputs individually connected to the gain control inputs 1-1 to 51-4 is provided.

Carrier extractor 51-1 and carrier extractor 3
The difference from the configuration 1-1 is that the power measurement unit 33-1, the averaging unit 34-1, the comparator 35-1, and the gain control unit 36-1 are not provided, and the multipliers 32-11 and 32-1 are not provided. The -12 multiplier input is connected to the corresponding output of the power monitor 52 as the gain control input described above. The power monitoring unit 52 is connected to a frequency analysis unit (FFT) 53 arranged at the first stage, an averaging unit 54 arranged at a stage subsequent to the frequency analysis unit 53, and one input is connected to an output of the averaging unit 54. A comparator 55 in which a predetermined threshold value is given as a constant to the other input, and carrier extraction units 51-1 to 51-1 at a stage subsequent to the comparator 55
And a gain control unit 56 for giving in parallel four multipliers to a gain control input of -4.

The operation of this embodiment will be described below. First, the carrier extraction units 51-1 to 51-4 are provided with a quadrature demodulator 86.
And the same processing is performed in parallel at the subsequent stage. Therefore, in the following, these carrier extraction units 5
For items common to 1-1 to 51-4, subscript "1"
The description will be made using a code with “C” added thereto, which can correspond to any of these additional numbers, instead of “−4”.

The power monitoring unit 52 includes a frequency analysis unit 53
Generates a scalar demodulated signal by taking the vector sum of the above-described two channel I and Q signals among the components of the demodulated signal given by the quadrature demodulator 86, and fast Fourier transforms the scalar demodulated signal. By,
The power in the occupied band of the four radio frequency signals described above is obtained as a frequency spectrum.

The averaging unit 54 performs a predetermined smoothing process on these powers to obtain an average power of the four radio frequency signals described above. The comparator 55 calculates the difference between these four average powers and the specified threshold value in parallel, and the gain control unit 56 determines whether the carrier extraction unit 51-C (multipliers 32-C1, 3-2
2-C2) is given in parallel the multiplier of the value by which these differences are compressed.

That is, the powers of the components included in the demodulated signal corresponding to the four radio frequency signals are collectively and simply obtained under the fast Fourier transform performed by the frequency analysis unit 53, and the feedforward method is used. , The deviation of these powers is compressed with high accuracy. Therefore, in the radio base station to which the present embodiment is applied, as long as a regular frequency arrangement adapted to such a fast Fourier transform is applied, the number of carrier extraction units to be mounted and the allocated radio frequency Can be flexibly adapted to the combination of hardware, and hardware standardization and simplification can be achieved.

FIG. 6 is a diagram showing a third embodiment of the present invention. In the figure, the configuration differs from the embodiment shown in FIG. 3 in that carrier extraction units 61-1 to 61-4 are provided instead of the carrier extraction units 31-1 to 31-4. Also,
The difference between the carrier extractor 61-1 and the carrier extractor 31-1 is that the digital filters 63-1 and 32-12 are not provided and the digital filter 63-1 is used instead of the digital filter 93-1.
2-1 is provided, and the output of the gain control unit 36-1 is connected to the control terminal of the digital filter 62-1.

Since the configuration of the carrier extraction units 61-2 to 61-4 is the same as the configuration of the carrier extraction unit 61-1, the corresponding components will be replaced with the subscript "1" in the following. The same reference numerals to which the suffix numbers “2” to “4” are added are given, and the description thereof is omitted here. The digital filter 62-1 is
The delay elements 63-11 and 63-12 of a predetermined number n of stages respectively corresponding to the two channels I and Q described above, the input terminals of these delay devices 63-11 and 63-12 and the output of each stage are One input is individually connected to the other, and the gain control unit 36 is connected to the other input.
Multipliers 64-111 to 64-11 (n + 1), 64-121 to 64-12 to which predetermined coefficients K-11 and K-12 are given in parallel by -1
(n + 1), multipliers 64-111 to 64-11 (n + 1), and multiplier 64-
Adders 65-11 arranged individually as the final stage, taking the sum of the values obtained in the outputs 121 to 64-12 (n + 1),
65-12.

The digital filters 62-2 to 62-4
Is the same as the configuration of the digital filter 62-1. In the following, the same numbers are assigned to the corresponding components with the addition of the additional numbers "2" to "4" instead of the additional number "1". The description is omitted here. Hereinafter, the operation of the present embodiment will be described.

First, the power measuring unit 33-C and the averaging unit 34-C
The processing performed by the comparator 35-C in coordination is the same as in the first embodiment described above, and a description thereof will not be repeated.

At the time of starting, the gain control unit 36-C has the above-mentioned multipliers 64-C11 to 64-C1 (n + 1), 64-C21 to 64-C2.
To (n + 1), prescribed coefficients K-C1 and K-C2 that give the filtering characteristics that the digital filter 62-C should originally have are given. When the gain control unit 36-C finds the multiplier in the same manner as in the first embodiment, the multipliers 64-C11 to 64-C1 (n +
1), 2-C21 to 64-C2 (n + 1) are given two coefficients which are respectively equal to the product of the multiplier and the above-mentioned specified coefficients K-C1 and K-C2.

In the digital filter 62-C, delay elements 63-C1, 63-C2, multipliers 64-C11 to 64-C1 (n + 1), 6
4-C21 to 64-C2 (n + 1) and adders 65-C1, 65-C2
Operates as a transversal type filter based on these two coefficients, thereby achieving
The gain proportional to the two coefficients is maintained as a transfer characteristic, and a predetermined filtering process is continuously performed on the demodulated signals corresponding to the two channels I and Q described above.

Therefore, according to this embodiment, the coefficients of the existing digital filter are appropriately multiplied by the coefficients which are real numbers, thereby providing the multipliers 32-C1, 32-C provided in the above-described first embodiment. The adjustment of the gain made for the individual radio frequency signals is likewise realized by C2. In the present embodiment, the processing for realizing gain adjustment in place of the multipliers 32-C1 and 32-C2 is performed by the carrier extraction unit 61-C
This is realized by multiplying a coefficient that gives the filtering characteristic of the digital filter 62-C provided in the above by a multiplier that is a real number.

However, the present invention is not limited to such a configuration. For example, as shown in FIG. 7, the following configuration may be applied. A complex coefficient exp (-j2πft) (= cos2πft) to be multiplied by the demodulated signal provided by the quadrature demodulator 86 to shift the demodulated signal on a frequency axis over a desired frequency f.
In the process of generating (+ jsin2πft), a trigonometric function table 71 for providing a real part (sin2πft) and an imaginary part (sin2πft) of the complex coefficient is provided (may be configured as a ROM or the like).

The trigonometric function table 71 stores in advance all the possible values of the multipliers described above and the product of the real part and the imaginary part. Further, the trigonometric function table 71 stores the gain control unit 36
-C reads the values of the real part and the imaginary part corresponding to the multiplier given, and symbol values i and q individually given via two mutually orthogonal channels I and Q for giving a demodulated signal, and these real parts and Multiplier 72-C1c, 72 for calculating the product sum with the imaginary part
-C1s, 72-C2c, 72-C2s are given as multipliers.

In each of the above embodiments, the present invention is applied to a mobile communication system to which the wideband CDMA system is applied. However, the present invention is not limited to such a mobile communication system. In a radio station where a reception wave composed of a sum of a plurality of individually modulated radio frequency signals can arrive in parallel, the vicinity of the feeding end of the antenna If it is required that demodulation processing be applied to the received wave in a lump, the same applies to a wireless transmission system to which any modulation method, multiple access method, zone configuration, channel arrangement and frequency arrangement are applied. Is possible.

[0060]

As described above, according to the first and second aspects of the present invention, the transmission characteristics of the radio channels formed in the bands of the individual radio frequency signals are stable while the cost of the antenna system is reduced. To be kept high. According to the third aspect of the present invention, the hardware configuration can be simplified as long as each of the plurality of radio frequency signals arriving as the received wave is a signal generated based on the quadrature modulation method. .

Further, the invention described in claim 4 is realized by actively applying digital signal processing without deteriorating performance. According to the fifth and sixth aspects of the present invention, the difference between the levels of a plurality of radio frequency signals arriving as received waves is reduced as compared with the case where individual means provided corresponding to these radio frequency signals are compressed. hand,
The scale of the hardware is reduced and the configuration is simplified.

Therefore, in the radio transmission system to which these inventions are applied, it is possible to flexibly adapt to a desired multiple access system, modulation system, zone configuration, channel allocation and frequency allocation, and furthermore to achieve high transmission quality and high service quality. Is achieved with high accuracy and at low cost.

[Brief description of the drawings]

FIG. 1 is a principle block diagram of the invention according to claims 1, 3 and 5;

FIG. 2 is a principle block diagram of the invention according to claims 2, 4, and 6;

FIG. 3 is a diagram showing a first embodiment of the present invention.

FIG. 4 is a diagram illustrating another configuration of the carrier extraction unit.

FIG. 5 is a diagram showing a second embodiment of the present invention.

FIG. 6 is a diagram showing a third embodiment of the present invention.

FIG. 7 is a diagram showing another configuration that enables gain adjustment.

FIG. 8 is a diagram illustrating a configuration example of a wireless receiver adapted to a wideband CDMA scheme.

FIG. 9 is a diagram illustrating the operation of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Batch demodulation means 12 Frequency conversion means 13, 22 Level correction means 21 Monitoring means 31, 51, 61, 87 Carrier extraction part 32, 64, 72 Multiplier 33 Power measurement part 34, 54 Averaging part 35, 55 Comparator 36 , 56, 91 Gain control unit 41 Absolute value acquisition unit 42, 73 Adder 52 Power monitoring unit 53 Frequency analysis unit (FFT) 62, 93 Digital filter 63 Delay element 65 Adder 71 Trigonometric function table 81 Antenna 82 Low noise amplifier 83 Frequency converter 84 Intermediate frequency filter 85 AGC unit 86 Quadrature demodulator 88 Local oscillator 89 Variable gain amplifier 90 A / D converter (A / D) 92 Frequency shift unit

Continued on the front page (72) Inventor Tokuro Kubo 4-1-1, Kamidadanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture Inside Fujitsu Limited (72) Inventor Takayoshi Oide 4-1-1, Kamiodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture No. Fujitsu Limited (72) Inventor Kazuo Hase 4-1-1 Kamikadanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture Fujitsu Limited (72) Inventor Hiroyoshi Ishikawa 4-1-1, Kamiodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture No. Fujitsu Limited F term (reference) 5K022 EE01 EE31 5K061 AA11 BB12 CC11 CC23 CC52 CD04

Claims (6)

[Claims] 1. A reception wave obtained by synthesizing a plurality of N radio frequency signals having different occupied bands is received, and demodulated collectively while maintaining the level of the reception wave at a predetermined value. Collective demodulation means for outputting a combined demodulated signal obtained by combining a plurality of N demodulated signals distributed in different bands corresponding to each other; and a plurality of N demodulated signals included in the combined demodulated signal output by the collective demodulation means. A radio receiver comprising a plurality of N frequency conversion means for individually outputting as signals distributed in a common band, wherein the power of the signals individually output by the plurality of N frequency conversion means is simultaneously adjusted to a desired accuracy. 2. A radio receiver comprising a plurality of N level correcting means for maintaining a predetermined value. 2. A reception wave obtained by combining a plurality of N radio frequency signals having different occupied bands is received, demodulated collectively while maintaining the level of the reception wave at a predetermined value, and Collective demodulation means for outputting a combined demodulated signal obtained by combining a plurality of N demodulated signals distributed in different bands corresponding to each other; and a plurality of N demodulated signals included in the combined demodulated signal output by the collective demodulation means. In a wireless receiver including a plurality of N frequency conversion units that individually output as signals distributed in a common band, a monitoring unit that calculates a deviation of power distributed in each occupied band of the plurality of N demodulated signals, The power deviations obtained by the monitoring means for the respective occupied bands of the plurality N of demodulated signals are fetched, and these deviations are corrected in parallel at the subsequent stage of the plurality N of frequency conversion means. A radio receiver comprising a plurality of N level correction means. 3. The radio receiver according to claim 1, wherein the collective demodulating means quadrature demodulates the received wave and outputs a composite demodulated signal corresponding to each of two mutually orthogonal channels. The conversion means outputs signals distributed in a common band as two signals respectively corresponding to the two orthogonal channels, and the plurality N of level correction means 13-1 to 13-N output the signals orthogonal to each other. The power of the signals individually output by the plurality of N frequency conversion means is identified as the sum of squares of the symbol values or instantaneous values of two signals respectively corresponding to the two channels or the average value of the sum. Radio receiver. 4. The radio receiver according to claim 2, wherein the monitoring means determines the power of a single or a plurality of frequency components distributed in an occupied band of the plurality of N demodulated signals by frequency thinning.
A wireless receiver for determining a deviation of power distributed in these bandwidths by performing T. 5. The radio receiver according to claim 1, wherein the plurality N of level correcting means are applied to a filtering process performed on the plurality N of demodulated signals in the digital domain by the plurality N of frequency converting means. A radio receiver characterized by maintaining the power of signals individually output by these frequency conversion means at a specified value by changing coefficients. 6. The radio receiver according to claim 2, wherein the plurality of N level correction means are applied to a frequency conversion process performed on the plurality of N demodulated signals in the digital domain by the plurality of N frequency conversion means. A radio receiver which corrects in parallel the power deviation obtained by the monitoring means for these demodulated signals by varying the absolute value of a power complex coefficient.