JP2009088589A - Radio communication method, radio reception method, radio communication system and radio receiver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radio communication method capable of easily and sufficiently taking countermeasures against frequency selectivity fading without requiring complicated reception processing. <P>SOLUTION: When a regular image modulation signal having a regular image waveform A and a mirror image modulation signal having a mirror waveform B are transmitted from a terminal side and received by a terminal of a designated communication opposite party via a base station (not shown), the communication opposite party in the terminal executes, as reception processing, demodulation processing on the basis of any one of the waveforms (regular image waveform A and mirror image waveform B) of the regular image modulation signal and mirror image modulation signal which are sampled in sampling each of the modulation signals on the basis of a reference line including a sampling point (fs) existing at the linear symmetrical position of the regular image waveform A and the mirror image waveform B. In the demodulation processing, the sampled regular image modulation signal and the mirror image modulation signal are in-phase composited and superimposed (the mirror image waveform B is returned for the regular image waveform A), thereby recovering the regular image waveform A as an original waveform. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a wireless communication method, a wireless reception method, a wireless communication system, and a wireless reception device that can simplify and sufficiently take measures against frequency selective fading.

  Conventionally, a modulation signal having a spectrum component of a predetermined waveform that is generally generated in a wireless communication device, for example, when transmitted by a single carrier method, the signal level is steadily decreasing due to the influence of frequency selective fading. It is known that communication quality deteriorates.

  Therefore, in order to improve the resistance to such frequency selective fading, in recent years, multi-carrier transmission that disperses modulated wave information has been widely used. For example, cost reduction and downsizing can be achieved. For example, a wireless transmission / reception device (see Patent Document 1) having a loopback function (own loopback test function) at a radio frequency and an intermediate frequency is eliminated.

JP-A-6-152461

  In the case of the wireless transmission / reception apparatus according to Patent Document 1 described above, the multi-carrier transmission applied here has an advantage that it is generally resistant to frequency selective fading.

  However, a decrease in signal level due to frequency selective fading of a plurality of modulated signals under the condition that the information of the modulated wave is dispersed to widen the frequency band (noticeable with low frequency modulation signals, but higher frequency side) In order to avoid the original information itself can be restored to some extent by performing error correction and other processing after demodulation, the sampling point is maximized during demodulation during normal reception. Must be set to at least twice the operating frequency (higher sampling frequency). As a result, there is a problem that signal processing on the receiving side becomes complicated.

  That is, the local station loopback test function at the radio frequency and the intermediate frequency proposed in the radio transmission / reception apparatus according to Patent Document 1 requires complicated reception processing (demodulation) of the superheterodyne method. There is a problem that it is difficult to implement.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide a radio communication method and a radio reception method that do not require a complicated reception process and that can easily achieve a frequency-selective fading countermeasure. Another object is to provide a wireless communication system and a wireless reception device.

To achieve the above object, a wireless communication method according to the present invention is a wireless communication method for performing wireless communication between terminals via a base station.
On the terminal side, a positive image modulation signal having a predetermined waveform in a predetermined frequency band, and a mirror image modulation signal generated so as to become a mirror image waveform by inverting the phase of the predetermined waveform in a frequency band higher than the normal image modulation signal. Send
On the base station side, when the normal image modulation signal and the mirror image modulation signal are received, the communication partner side of the terminal is determined and then the normal image modulation signal and the mirror image modulation signal are transmitted by communication control.
On the communication counterpart side in the terminal, as a reception process when the normal image modulation signal and the mirror image modulation signal are received, the predetermined waveform that exists in a position that is line-symmetric with respect to the predetermined waveform and the mirror image waveform on the frequency axis. Sampling is performed based on a reference line including the sampling points.
If the communication partner side of the terminal is the own station, the own station loopback test function similar to the case of Patent Document 1 is constructed. However, according to the above method, the reception processing here is performed on the frequency axis regardless of the communication partner side. Since each modulation signal is sampled on the basis of a reference line including a predetermined sampling point that exists at a line-symmetrical position of each modulation signal waveform, signal processing on the reception side is simplified.

In the wireless communication method according to the present invention, the communication counterpart in the terminal performs demodulation based on the waveform of either the sampled normal image modulation signal or the mirror image modulation signal as the reception process. Including processing.
According to the above method, even if either the normal image component or the mirror image component of the modulation signal is suppressed by frequency selective fading, it is possible to accurately perform demodulation after sampling based on the one having less influence of frequency selective fading. it can.

In the radio communication method according to the present invention, in the demodulation process, the sampled normal image modulation signal and the mirror image modulation signal are in-phase synthesized and superimposed to restore the predetermined waveform as an original waveform. Features.
According to the above method, even if any one of the normal image component or the mirror image component of the modulation signal is suppressed by frequency selective fading, the original information can be easily restored by synthesizing the waveform of each modulation signal.

In addition, the radio reception method according to the present invention is configured so that a positive image modulation signal having a predetermined waveform in a predetermined frequency band and a phase of the predetermined waveform in a frequency band higher than the normal image modulation signal are inverted to form a mirror image waveform. When receiving the mirror image modulation signal generated in the step S1, a reception process is performed in which sampling is performed based on a reference line including a predetermined sampling point existing in a line-symmetric position between the predetermined waveform and the mirror image waveform on the frequency axis. It is characterized by that.
Assuming that a modulated signal having a normal image component and a mirror image component of a waveform transmitted as wireless communication is received by the above-described method, the reception processing includes a predetermined waveform and a mirror image waveform on the frequency axis. Since the modulation signal is sampled based on a reference line including a predetermined sampling point that exists at a line-symmetrical position, signal processing on the reception side is simplified.

The radio reception method according to the present invention is characterized in that the reception process includes a demodulation process for performing demodulation based on one of the sampled waveforms of the normal image modulation signal and the mirror image modulation signal.
By the above method, it is possible to accurately perform demodulation after sampling based on the one having less influence of frequency selective fading.

In the radio reception method according to the present invention, in the demodulation process, the sampled normal image modulation signal and the mirror image modulation signal are in-phase synthesized and superimposed to restore the predetermined waveform as an original waveform. Features.
By the above method, the original information can be easily restored by synthesizing the waveforms of the modulated signals.

In addition, a wireless communication system according to the present invention performs communication control for determining a communication partner between a plurality of terminals capable of wireless communication with each other in a predetermined frequency band and performing the wireless communication. A wireless communication system comprising:
The plurality of terminals are:
A signal generation transmission processing function for transmitting a normal image modulation signal having a predetermined waveform and a mirror image modulation signal generated so as to be a mirror image waveform by inverting the phase of the predetermined waveform in a frequency band higher than the normal image modulation signal;
When the normal image modulation signal and the mirror image modulation signal are received from the communication partner determined by the base station, as a reception process, a predetermined signal existing in a line-symmetric position between the predetermined waveform and the mirror image waveform on the frequency axis A reception processing function for performing sampling based on a reference line including a sampling point;
The base station, when receiving the normal image modulation signal and the mirror image modulation signal from an arbitrary one of the plurality of terminals, determines a communication partner and transmits the normal image modulation signal and the mirror image modulation signal by communication control. It has a control function.
If the communication partner of the terminal is its own station, the own station loopback test function similar to that in the case of Patent Document 1 is constructed. However, in the above wireless communication system, as the reception process, the frequency axis is used regardless of the communication partner side. Since each signal is sampled on the basis of a reference line including a predetermined sampling point that exists at a position where line symmetry of each signal waveform is formed, the configuration for performing reception processing is simplified.

In the wireless communication system according to the present invention, the reception processing function in the plurality of terminals may perform demodulation based on the waveform of either the sampled normal image modulation signal or the mirror image modulation signal as the reception processing. It includes a demodulation process to be performed.
Even if either the normal image component or the mirror image component of the modulation signal is suppressed by frequency selective fading by the above wireless communication system, it is accurate based on the one that has less influence of frequency selective fading after sampling with a simple configuration. Can be demodulated.

In the radio communication system according to the present invention, in the demodulation process, the sampled normal image modulation signal and the mirror image modulation signal are in-phase synthesized and superimposed to restore the predetermined waveform as an original waveform. Features.
Even if one of the above-mentioned normal image component or mirror image component of the modulation signal is suppressed by frequency selective fading by the above wireless communication system, the original information can be easily obtained by synthesizing the waveform of each modulation signal with a simple configuration. Can be restored.

The wireless communication system according to the present invention is characterized in that the plurality of terminals are PHS terminals that perform the wireless communication by a multicarrier system.
With the above wireless communication system, the reception processing function of the PHS terminal has a simple configuration that can sufficiently take measures against frequency selective fading without requiring complicated reception processing, and the entire system can be provided at low cost.

In addition, the wireless reception device according to the present invention reverses the phase of the predetermined waveform in a predetermined waveform in a predetermined frequency band and in a higher frequency band than the normal image modulation signal to obtain a mirror image waveform. Receiving processing function for performing sampling based on a reference line including a predetermined sampling point existing in a line-symmetrical position between the predetermined waveform and the mirror image waveform on the frequency axis when receiving the mirror image modulation signal generated It is characterized by having.
With the above configuration, it is assumed that a modulated signal having a normal image component and a mirror image component whose waveforms transmitted by wireless communication are axisymmetric, and the reception process is the same as that of the wireless communication system (invention 7). Since sampling is performed by processing, similarly, signal processing on the receiving side can be performed with a simple configuration.

The radio reception apparatus according to the present invention is characterized in that the reception processing function includes a demodulation process for performing demodulation based on the sampled waveform of the normal image modulation signal or the mirror image modulation signal. .
With the above configuration, it is possible to perform accurate demodulation based on the one with less influence of frequency selective fading after sampling with a simple configuration.

In the demodulation process, the radio receiving apparatus according to the present invention restores the predetermined waveform as an original waveform by performing in-phase synthesis of the sampled normal image modulation signal and the mirror image modulation signal and superimposing them. Features.
With the above configuration, the original information can be easily restored by synthesizing the waveforms of the modulated signals with a simple configuration.

  According to the radio communication method and radio reception method of the present invention, signal processing at the time of transmission by the single carrier method while maintaining the frequency selective fading characteristics at the time of transmission by the multicarrier method without requiring complicated reception processing and Reception processing can be performed by an equivalent simple method. Further, even in a wireless communication system and a wireless reception device to which these wireless communication methods and wireless reception methods are applied, signal generation transmission processing functions responsible for similar transmission processing and reception processing functions responsible for reception processing, respectively, have a simple configuration. Can be built.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a schematic diagram showing the frequency arrangement of a modulated signal to be transmitted in the radio communication method according to the embodiment of the present invention in relation to the signal level.

  In FIG. 1, when transmitting a modulation signal from the terminal side, a normal image modulation signal having a normal image waveform A on the low frequency band side and a mirror image waveform B in which the phase arranged on the higher frequency band side is inverted are displayed. It shows how the mirror image modulation signal is transmitted (both are shown as a single carrier spectrum). The intermediate point between the normal image waveform A and the mirror image waveform B on the frequency axis is a line symmetry point fx indicating the line symmetry position of these waveforms.

FIG. 2 is a schematic diagram showing the arrangement of modulated signals received and processed in the wireless communication method according to the best mode of the present invention in relation to the signal level with respect to the frequency.
In FIG. 2, during reception processing on the communication partner side in the terminal, the terminal exists at a position that is line symmetric with respect to the normal image waveform A of the normal image modulation signal corresponding to the previous line symmetry point fx and the mirror image waveform B of the mirror image modulation signal. A mode in which each modulation signal is sampled based on a reference line including the sampling point fs is shown.

  On the communication partner side in the terminal, as a reception process, a demodulation process is performed in which demodulation is performed based on any waveform of the sampled normal image modulation signal and mirror image modulation signal (that is, either the normal image waveform A or the mirror image waveform B). Execute.

  In this demodulating process, the sampled normal image modulation signal and mirror image modulation signal are in-phase synthesized and superimposed to restore the normal image waveform A as the original waveform. Here, the mirror image waveform B is folded and overlapped with the normal image waveform A so as to be the normal image waveform A + mirror image waveform B. However, the demodulation process itself involves the normal image waveform A with respect to the mirror image waveform B. Folded and overlapped, or one of normal image waveform A and mirror image waveform B, which is less affected by frequency selective fading and has a lower signal level drop (which corresponds to a mirror image modulation signal having a higher normal frequency band) Based on this, the original waveform may be restored.

  Incidentally, in order to generate a normal image modulation signal and a mirror image modulation signal based on a reference line including a sampling point (sampling frequency) fs, it is used for frequency band filtering such as an FIR filter, and the falling edge of the normal image waveform A It is effective to use an anti-aliasing filter C having a filtering characteristic that can specify the rising start frequency of the mirror image waveform B with respect to the terminal frequency.

  According to such a wireless communication method, if the communication partner side of the terminal is the own station, the own station loopback test function similar to the case of Patent Document 1 is constructed. Regardless, since each modulation signal is sampled based on a reference line including the sampling point fs, signal processing on the reception side is simplified.

  In addition, even if either the normal image component or the mirror image component of the modulation signal is suppressed by frequency selective fading, it becomes possible to perform demodulation based on the one with less influence of frequency selective fading after sampling, Further, in the demodulation processing, the normal image waveform A is restored as the original waveform by in-phase synthesis of the components and superimposing them, so that the signal processing on the receiving side is simpler than in the case of Patent Document 1.

  As a result, it is possible to perform reception processing using a simple method equivalent to signal processing during transmission using the single carrier method while maintaining the frequency-selective fading characteristics during transmission using the multicarrier method without requiring complex reception processing (diversity). Therefore, the frequency selective fading countermeasure can be simplified and sufficiently achieved.

  By the way, the same reception processing is performed also in the wireless reception method of the present invention based on the premise that a modulated signal having a normal image component and a mirror image component in which the waveform transmitted by wireless communication is axisymmetric is received. .

  That is, when the normal image modulation signal of the normal image waveform A and the mirror image modulation signal of the mirror image waveform B in which the phase of the higher frequency band is inverted are received based on the reference line including the sampling point fs on the frequency axis. When performing demodulation processing that performs sampling based on the waveform of one of the positive image modulation signal and mirror image modulation signal sampled in the reception processing, the normal image modulation signal and mirror image modulation signal are in-phase synthesized. Since the original waveform is restored by superimposing, the same effect can be obtained.

  In addition, in the wireless communication system to which the above-described wireless communication method of the present invention is applied, a plurality of terminals capable of performing wireless communication with each other in a predetermined frequency band and a communication partner between the terminals are determined and wireless communication is performed. The basic configuration is provided with a base station that performs communication control.

  By taking this basic configuration, for each terminal, the above-described signal generation and transmission processing function for transmitting the normal image modulation signal and the mirror image modulation signal and the normal image modulation signal and the mirror image modulation signal from the communication partner determined by the base station are received. When receiving, the reception processing has a reception processing function for performing sampling based on a reference line including the sampling point fs on the frequency axis.

  The base station has a communication control function for determining the communication partner and transmitting the normal image modulation signal and the mirror image modulation signal by communication control when receiving the normal image modulation signal and the mirror image modulation signal from any one of the terminals. It will be a thing.

  However, the signal generation and transmission processing function in each terminal here specifies the communication partner in advance, and the communication control function in the base station performs communication control after authenticating the specified communication partner. is there.

  The reception processing function in each terminal in this wireless communication system includes a demodulation process for performing demodulation based on the waveform of either the sampled normal image modulation signal or mirror image modulation signal as the reception process. Then, the sampled normal image modulation signal and mirror image modulation signal are in-phase synthesized and superimposed to restore a predetermined waveform as an original waveform.

  Even in the case of this wireless communication system, a simple technique equivalent to signal processing during transmission using the single carrier method while maintaining the frequency-selective fading characteristics during transmission using the multicarrier method without requiring complex reception processing. Therefore, the frequency selective fading countermeasure can be sufficiently achieved with a simple configuration.

  In particular, in a communication system in which each terminal is a PHS terminal that performs wireless communication by a multicarrier system, the reception processing function of the PHS terminal can easily take measures against frequency selective fading without requiring complicated reception processing. The entire system can be simplified.

  In addition, even in the case of a wireless reception device to which the above-described wireless reception method of the present invention is applied, it is assumed that the waveform transmitted by wireless communication receives a modulated signal having a normal image component and a mirror image component that are axisymmetric. A similar reception process is performed.

  That is, when the normal image modulation signal of the normal image waveform A and the mirror image modulation signal of the mirror image waveform B in which the phase of the higher frequency band is inverted are received based on the reference line including the sampling point fs on the frequency axis. It has a reception processing function for performing sampling processing for sampling, and as a reception processing of the reception processing function, in the demodulation processing for demodulating based on the waveform of one of the sampled normal image modulation signal and mirror image modulation signal, Since the modulation signal and the mirror image modulation signal are combined in phase and superimposed to restore the original waveform, the same effect can be obtained with an equivalently simple configuration.

  In the following, the wireless communication system and the wireless receiving device of the present invention will be described in detail with reference to the drawings, with specific examples.

  FIG. 3 is a block diagram illustrating a basic configuration of a wireless transmission device provided in a PHS terminal applied to the wireless communication system according to the embodiment of the present invention, including signal waveforms of main parts.

  In the case of this wireless transmission device, a digital signal of a predetermined level is generated from a signal generator 11 in a predetermined radio frequency band, and this digital signal is digital / analog converted by a digital / analog converter (DAC) 12 as a result. A baseband generation signal by a level rectangular wave is output.

  This baseband generation signal is subjected to frequency mixing processing with a local oscillator 14 having a frequency f (Lo1) in a mixer (mixer) 13 having a multiplication function. A normal image signal and a mirror image signal based on a reference line including the frequency f (Lo1) as a line symmetry point, a normal image signal and a mirror image signal based on a reference line including the frequency f2 (Lo1) twice as a line symmetry, and a triple thereof A normal image signal and a mirror image signal are output based on a reference line including the frequency f3 (Lo1) as a line symmetry point.

  When each of these signals is filtered by a band-pass filter (BPF) 15, only a normal image signal and a mirror image signal based on a reference line including the frequency f (Lo 1) as a line symmetry point are output, which are output in the intermediate frequency band ( After being amplified by an amplifier (IFA) 16 for IF), it is sent to a mixer (mixer) 17 having a multiplication function.

  In the mixer (mixer) 17, the input signal is subjected to frequency mixing processing with the local oscillator 18 having the frequency f (Lo2) and then sent to the bandpass filter (BPF) 19. As a result, the filtered signal is illustrated. Thus, the frequency f (Lo1) + f (Lo2) obtained by adding the frequency f (Lo2) to the frequency f (Lo1) is a line symmetry point f (tx) [ie, f (tx) = f (Lo1) + f (Lo2)] The normal image signal and the mirror image signal based on the reference line included as follows are amplified by the radio frequency band (RF) amplifier (RFA) 16, and then the positive image modulation based on the reference line including the line symmetry point f (tx) The signal and the mirror image modulation signal are wirelessly transmitted by the multicarrier system via the transmission antenna 21.

As described above, in this wireless transmission device, a signal generation transmission processing function for transmitting a normal image modulation signal and a mirror image modulation signal based on the reference line including the line symmetry point f (tx) is constructed.
In addition, in the signal generation and transmission processing function of the wireless transmission device mounted on such a PHS terminal, the communication partner can be designated in advance, so that the base station (not shown) to which each modulated signal is transmitted After authenticating the communication partner designated by the communication control function, communication control is performed, and a normal image modulation signal and a mirror image modulation signal based on a reference line including a line symmetry point f (rx) described later are transmitted to the communication partner.

  FIG. 4 is a block diagram illustrating a basic configuration of a wireless reception device provided in a PHS terminal applied to a PHS system (wireless communication system) according to an embodiment of the present invention, including signal processing waveforms of main parts.

  In the case of this radio receiving apparatus, when a normal image modulation signal and a mirror image modulation signal based on a reference line including a line symmetry point f (rx) are received by a multicarrier system via a receiving antenna 22 as shown in the figure. After being filtered by the bandpass filter (BPF) 23, it is amplified by the low noise amplifier (LNA) 24 and then sent to the mixer (mixer) 25.

  The mixer (mixer) 25 performs frequency mixing processing on the input signal with the local oscillator 26 having a predetermined frequency, and outputs a signal having a frequency f (rx) ± f (Local) component. This frequency f (rx) ± f (Local) component signal is branched and transmitted and filtered by a signal bandpass filter (BPF) 27, and the frequency f (rx) −f ( Local) is output as a normal image modulation signal and a mirror image modulation signal based on a reference line including a line symmetry point f (IF) [ie, f (IF) = f (rx) −f (Local)].

  On the other hand, with respect to what has been filtered by the bandpass filter (BPF) 28 such as the anti-aliasing filter for the lowest resonance frequency, the mirror image waveform from the trailing end frequency of the normal image waveform as shown by the dotted line in the figure. A positive image signal based on a reference line including a sampling frequency f (IF) as an intermediate position (line symmetric position) between the normal image waveform and the mirror image waveform based on the filtered (BPF) characteristic of the convex waveform reaching the rising start frequency of It is output as a mirror image signal and sent to the phase comparator 29.

  The phase comparator 29 compares the phases of the positive image waveform and the mirror image waveform in the normal image signal and the mirror image signal based on the reference line including the sampling frequency f (IF), and outputs a phase difference signal indicating the phase difference to the frequency variable oscillator ( VCO) 30. The variable frequency oscillator (VCO) 30 compensates the phase difference by varying the frequency to convert a sampling frequency signal indicating an intermediate frequency (sampling point on the frequency axis) between the normal image waveform and the mirror image waveform to an analog / digital converter ( ADC) 31. Since a part of the sampling frequency signal is fed back to the phase comparator 29, the phase difference compensation in the phase comparator 29 is always performed optimally.

  In an analog / digital converter (ADC) 31, a positive image modulation signal based on a reference line including a sampling frequency signal from a frequency variable oscillator (VCO) 30 and a line symmetry point f (IF) from a bandpass filter (BPF) 27. Then, the mirror image modulation signal is analog / digital converted and sent to the demodulation processor 32. In the demodulation processor 32, the mirror image modulation signal is in-phase synthesized with the normal image modulation signal based on the sampling frequency f (IF) indicating the sampling point fs indicated in the digitized sampling frequency signal and superimposed (mirror image). The waveform is folded back to a normal image waveform), and demodulation processing is performed by restoring the original waveform of the normal image modulation signal.

  As described above, in the radio reception apparatus provided in the PHS terminal, when a normal image modulation signal and a mirror image modulation signal are received from a communication partner determined by the base station, as a reception process, the reference line including the sampling point fs on the frequency axis is used. A reception processing function for performing sampling is constructed based on this, and the reception processing of the reception processing function includes a demodulation process for performing demodulation based on one of the waveform of the sampled normal image modulation signal and mirror image modulation signal. In the processing, a function of restoring the original waveform by in-phase synthesis of the normal image modulation signal and the mirror image modulation signal and superimposing them is obtained.

  In the demodulator 32 in the wireless receiver of the embodiment, the mirror image modulation signal is in-phase synthesized with the normal image modulation signal and superimposed to restore the original waveform of the normal image modulation signal. The demodulation process itself is made by synthesizing and synthesizing the normal image modulation signal with the mirror image modulation signal and superimposing them (the normal image waveform is folded back into the mirror image waveform), restoring the original waveform, or selecting the frequency The original waveform may be restored on the basis of the lowering of the signal level of either the normal image modulation signal or the mirror image modulation signal, which is less affected by sex fading, and is not limited to the disclosed form. .

  The above-described radio reception apparatus provided in the PHS terminal applied to the radio communication system according to the embodiment is not a PHS terminal, but a normal image component and a mirror image component in which waveforms transmitted by general radio communication are line symmetric. The present invention can also be applied to applications that assume the reception of modulated signals having

  That is, the configuration shown in FIG. 4 can be applied to a radio receiving apparatus other than the PHS terminal as it is, and the same reception processing function (including a sampling point fs on the frequency axis when a normal image modulation signal and a mirror image modulation signal are received). A reception process for sampling based on the reference line is performed, and the reception process includes a demodulation process for performing demodulation based on the waveform of either the sampled normal image modulation signal or mirror image modulation signal. And the mirror image modulation signal are in-phase synthesized and superimposed to restore the original waveform), so that the same effect can be obtained with an equivalently simple configuration.

It is the schematic diagram which showed the arrangement | positioning of the modulation signal transmitted in the radio | wireless communication method which concerns on embodiment of this invention by the relationship of the signal level with respect to a frequency. It is the schematic diagram which showed the arrangement | positioning of the modulation signal received and processed in the radio | wireless communication method which concerns on embodiment of this invention with the relationship of the signal level with respect to a frequency. It is the block diagram which illustrated the basic composition of the radio transmitter with which the PHS terminal applied to the radio communications system concerning the example of the present invention is included including the signal processing waveform of the principal part. It is the block diagram which illustrated the basic composition of the radio receiver provided in the PHS terminal applied to the radio communications system concerning the example of the present invention including the signal processing waveform of the principal part.

Explanation of symbols

11 Signal Generator 12 Digital / Analog Converter (DAC)
13, 17, 25 Mixer
14, 18, 26 Local oscillator 15, 19, 23, 27, 28 Bandpass filter (BPF)
16, 20, 24 Amplifier 21, 22 Antenna 29 Phase comparator 30 Variable frequency oscillator (VCO)
31 Analog / Digital Converter (ADC)
32 Demodulator A Normal image waveform B Mirror image waveform fs Sampling point fx Line symmetry point

Claims (13)

In a wireless communication method for performing wireless communication between terminals via a base station,
On the terminal side, a positive image modulation signal having a predetermined waveform in a predetermined frequency band, and a mirror image modulation signal generated so as to become a mirror image waveform by inverting the phase of the predetermined waveform in a frequency band higher than the normal image modulation signal. Send
On the base station side, when the normal image modulation signal and the mirror image modulation signal are received, the communication partner side of the terminal is determined and then the normal image modulation signal and the mirror image modulation signal are transmitted by communication control.
On the communication counterpart side in the terminal, as a reception process when the normal image modulation signal and the mirror image modulation signal are received, the predetermined waveform that exists in a position that is line-symmetric with respect to the predetermined waveform and the mirror image waveform on the frequency axis. Sampling is performed based on a reference line including the sampling points.   2. The communication partner side in the terminal includes, as the reception process, a demodulation process in which demodulation is performed based on one of the sampled waveforms of the normal image modulation signal and the mirror image modulation signal. The wireless communication method described.   3. The radio communication method according to claim 2, wherein, in the demodulation process, the predetermined waveform is restored as an original waveform by in-phase synthesis of the sampled normal image modulation signal and the mirror image modulation signal and superimposing them. .   When a normal image modulation signal having a predetermined waveform in a predetermined frequency band and a mirror image modulation signal generated so as to become a mirror image waveform by inverting the phase of the predetermined waveform in a frequency band higher than the normal image modulation signal are received. A radio reception method comprising: performing a reception process of sampling based on a reference line including a predetermined sampling point existing in a line-symmetric position between the predetermined waveform and the mirror image waveform on the frequency axis.   5. The radio reception method according to claim 4, wherein the reception process includes a demodulation process for performing demodulation based on a waveform of either the sampled normal image modulation signal or the mirror image modulation signal.   6. The radio reception method according to claim 5, wherein, in the demodulation process, the predetermined waveform is restored as an original waveform by in-phase synthesis of the sampled normal image modulation signal and the mirror image modulation signal and superimposing them. . A wireless communication system comprising: a plurality of terminals capable of wireless communication with each other in a predetermined frequency band; and a base station that performs communication control for determining a communication partner between the plurality of terminals and performing the wireless communication. In
The plurality of terminals are:
A signal generation transmission processing function for transmitting a normal image modulation signal having a predetermined waveform and a mirror image modulation signal generated so as to be a mirror image waveform by inverting the phase of the predetermined waveform in a frequency band higher than the normal image modulation signal;
When the normal image modulation signal and the mirror image modulation signal are received from the communication partner determined by the base station, as a reception process, a predetermined signal existing in a line-symmetric position between the predetermined waveform and the mirror image waveform on the frequency axis A reception processing function for performing sampling based on a reference line including a sampling point;
The base station, when receiving the normal image modulation signal and the mirror image modulation signal from an arbitrary one of the plurality of terminals, determines a communication partner and transmits the normal image modulation signal and the mirror image modulation signal by communication control. A wireless communication system having a control function.   The reception processing function in the plurality of terminals includes, as the reception processing, demodulation processing that performs demodulation based on any waveform of the sampled normal image modulation signal and the mirror image modulation signal. Item 8. The wireless communication system according to Item 7.   9. The radio communication system according to claim 8, wherein, in the demodulation process, the predetermined waveform is restored as an original waveform by in-phase synthesis of the sampled normal image modulation signal and the mirror image modulation signal and superimposing them. .   The wireless communication system according to claim 7, wherein the plurality of terminals are PHS terminals that perform the wireless communication by a multicarrier method.   When a normal image modulation signal having a predetermined waveform in a predetermined frequency band and a mirror image modulation signal generated so as to become a mirror image waveform by inverting the phase of the predetermined waveform in a frequency band higher than the normal image modulation signal are received. A radio receiving apparatus having a reception processing function of performing sampling based on a reference line including a predetermined sampling point existing at a position in line symmetry between the predetermined waveform and the mirror image waveform on the frequency axis.   The radio reception apparatus according to claim 11, wherein the reception processing function includes a demodulation process for performing demodulation based on a waveform of either the sampled normal image modulation signal or the mirror image modulation signal.   13. The radio receiving apparatus according to claim 12, wherein, in the demodulation process, the predetermined waveform is restored as an original waveform by in-phase synthesis of the sampled normal image modulation signal and the mirror image modulation signal and superimposing them. .

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