JP2007028436A - Wireless communication apparatus and communication quality estimation method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wireless communication apparatus capable of estimating the communication quality of a wireless communication system which is different from a wireless communication system under communication, in a short time by a simple configuration. <P>SOLUTION: A signal resulting from applying the baseband processing of a wireless communication system different from the original baseband processing of the wireless communication system to a known signal is stored as a reference signal in a reference signal library 7. Only a multimode wireless section 3 is set to a function corresponding to a wireless communication system to be estimated differently from a wireless communication system under communication, and in this state, a correlation is determined between a signal obtained by reception processing by the multimode wireless section 3 and a multimode baseband processing section 6 of the wireless communication system to be estimated and the reference signal. Based on a value of the correlation, the communication quality of a signal is estimated for the wireless communication system to be estimated differently from the wireless communication system under communication. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a wireless communication apparatus and a communication quality estimation method, for example, a wireless communication apparatus capable of communicating with a plurality of wireless communication systems using a single wireless apparatus, such as a software wireless apparatus or a multimode wireless apparatus, and such a wireless apparatus. The present invention relates to a communication quality estimation method used as a reference for switching between wireless communication systems in a communication apparatus.

  Currently, wireless communication systems include PDC (Personal Digital Cellular), GSM (Global System for Mobile Communications), W-CDMA (Wideband Code Division Multiple Access), and other wireless LANs, IEEE802.11a, b, g, and more. Various types such as PHS (Personal Handyphone System), Bluetooth, etc. are prevalent. In many cases, base stations of different types of wireless communication systems are installed in adjacent areas.

  FIG. 6 shows a case where the base station A of the wireless communication system A and the base station B of the wireless communication system B are installed in the same area. The radio communication systems A and B provide independent services, and the radio communication systems A and B are not compatible. Therefore, even if the terminal A of the wireless communication system A exists in an area where the service areas A and B of each wireless communication system overlap, the terminal A cannot use the service of the wireless communication system B. . In order for a user to use both services of the wireless communication systems A and B, the user must have a wireless terminal corresponding to each communication service.

  In order to eliminate such complexity, it is desirable that one wireless terminal can support a plurality of wireless communication systems. Therefore, a radio called a software defined radio corresponding to a plurality of radio communication systems is loaded by reading a program into digital signal processing hardware such as a DSP (Digital Signal Processor) or FPGA (Field Programmable Gate Array). A terminal has been researched and developed (for example, see Patent Document 1).

  FIG. 7 shows a configuration of a conventional software defined radio described in Patent Document 1. The software defined radio 10 includes an antenna 11, a duplexer 12, a radio unit (so-called multimode radio unit) 13, a signal processing unit (so-called multimode baseband processing unit) 14, an automatic line control unit 15, an overall control unit 16, communication A system storage unit 17 is provided. The wireless unit 13 includes a reception amplifier 13_1, a reception RF circuit 13_2, a transmission amplifier 13_3, and a transmission RF circuit 13_4.

  The overall control unit 16 sets the reception RF circuit 13_2 and the transmission RF circuit 13_4 to be compatible with the wireless communication system that receives the carrier frequency, and also communicates with the signal processing unit 14 and corresponds to the wireless communication system. Supply. In addition, the overall control unit 16 sends an instruction to the automatic line control unit 15 to evaluate the line quality.

  The radio unit 13 inputs a signal received by the antenna 11 through the duplexer 12, and amplifies the signal by the reception amplifier 13_1. The amplified signal is subjected to frequency conversion based on the carrier frequency set by the overall control unit 16 in the reception RF circuit 13_2 and supplied to the signal processing unit. The transmission RF circuit 13_4 obtains an RF signal by frequency-converting the baseband signal input from the signal processing unit 14 based on the carrier frequency set by the overall control unit 16, and supplies this to the transmission amplifier 13_3. To do. The RF signal amplified by the transmission amplifier 13_3 is transmitted from the antenna 11 via the duplexer 12.

  The signal processing unit 14 performs baseband processing such as demodulation processing of the signal acquired from the reception RF circuit 13_2 and modulation processing of the signal supplied to the transmission RF circuit 13_4 based on the communication control program acquired from the overall control unit 16. Do. The automatic line control unit 15 adds data for communication quality evaluation to the signal transmitted by the wireless unit 13 while changing the carrier frequency of the wireless unit 13 and the processing function of the signal processing unit 14 in cooperation with the overall control unit 16. To do. In addition, the automatic line control unit 15 evaluates the communication quality in a plurality of wireless communication systems based on the signal to which the communication quality evaluation data received from the outside is received by the wireless unit 13, and wireless communication with good communication quality. The system is selected, and the functions of the wireless unit 13 and the signal processing unit 14 are set to those corresponding to the selected wireless communication system.

Using such a software defined radio makes it possible not only to use both services of the wireless communication systems A and B, but also to switch the function to a wireless communication system with good communication quality according to the surrounding communication environment. Wireless communication can be performed with good communication quality.
Japanese Patent Laying-Open No. 2004-208098 (Section 3-6, FIG. 2)

  By the way, in the software defined radio 10 described in Patent Document 1, when the communication quality of a plurality of wireless communication systems is estimated by the automatic line control unit 15, the carrier frequency in the wireless unit 13 and the baseband processing function in the signal processing unit 14 The communication quality of a plurality of wireless communication systems is estimated while changing according to the wireless communication system to be estimated. For this reason, there has been a drawback that it takes time to estimate the communication quality of a plurality of wireless communication systems.

  In particular, when the function of the signal processing unit 14 is changed according to each wireless communication system, it is necessary to rewrite the configuration of the signal processing unit 14 based on the communication control program acquired from the overall control unit 16. The rewriting time of the unit 14 occurs. As a result, it takes time to estimate the communication quality, and there is a problem that the estimation of the communication quality is not in time for the change in the propagation path condition. This problem becomes more prominent as the propagation path condition changes faster.

  The present invention has been made in view of the above points, and a wireless communication apparatus and communication capable of estimating communication quality of a wireless communication system different from the wireless communication system in communication in a short time with a simple configuration An object is to provide a quality estimation method.

  In order to solve such a problem, a wireless communication apparatus of the present invention is a wireless communication apparatus that can communicate with a plurality of wireless communication systems, a multimode wireless unit that performs wireless processing corresponding to the plurality of wireless communication systems, and a plurality of wireless communication apparatuses A multimode baseband processing unit that performs baseband processing corresponding to a wireless communication system, and another wireless communication system that is different from the baseband processing of the corresponding wireless communication system for a baseband known signal for each wireless communication system A multi-mode radio unit in a state in which a signal obtained when the baseband processing is performed is stored in advance as a reference signal, and the multi-mode baseband processing unit is set to a function corresponding to the wireless communication system in communication Is set to a function corresponding to the estimation target wireless communication system different from the wireless communication system in communication. Based on the correlation result between the reference signal and the signal of the estimation target wireless communication system obtained by the reception processing by the multimode wireless unit and the multimode baseband processing unit set by the control unit. And a communication quality estimation unit that estimates a communication quality of a signal of a radio communication system to be estimated that is different from the radio communication system.

  According to this configuration, for example, during communication in the wireless communication system A, the multimode wireless unit and the multimode baseband processing unit are set to functions for the wireless communication system A. When estimating the communication quality of the wireless communication system B, the control unit causes the multimode baseband processing unit to remain the function for the wireless communication system A and the multimode wireless unit to function for the wireless communication system B. Set to Then, the received signal of the wireless communication system B converted into the baseband signal by the multimode wireless unit is subjected to the original baseband processing (that is, baseband processing corresponding to the wireless communication system B) by the multimode baseband processing unit. The baseband processing of the wireless communication system A that is currently communicating, which is different from FIG. As described above, the signal subjected to the baseband processing different from the original baseband processing is stored in the correlation calculation unit in advance in the storage unit, and other radio signals different from the baseband processing of the original wireless communication system are stored. Correlation with a signal obtained when baseband processing of a communication system is performed is obtained. That is, the correlation value between the ideal waveform (reference signal) stored in the storage unit and the actual waveform of the received signal is obtained by the correlation calculation unit. As a result, the closer the actual received waveform is to the ideal waveform, the higher the correlation value. The higher the correlation value, the better the communication quality estimation unit determines the communication quality.

  Thus, when estimating the communication quality of another wireless communication system different from the wireless communication system during communication in a certain wireless communication system, the function of the multimode baseband processing unit corresponds to the wireless communication system to be estimated. Even if it is not switched to the communication system, that is, it is possible to estimate the communication quality in the wireless communication system different from the wireless communication system in communication without changing the communication system. As a result, communication quality can be estimated in a short time.

  As described above, according to the present invention, it is possible to realize a wireless communication apparatus and a communication quality estimation method capable of estimating the communication quality of a wireless communication system different from the wireless communication system in communication with a simple configuration in a short time.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows a configuration of a wireless communication apparatus according to an embodiment of the present invention. In FIG. 1, the portions related to the present invention are mainly shown.

  The wireless communication apparatus 1 includes a control unit 2, a multimode wireless unit 3, a multimode baseband processing unit 6, a reference signal library 7, a program memory 8, and a communication quality estimation unit 9. .

  The multimode radio unit 3 includes radio units 3_1 to 3_3 and antennas 3_4 to 3_6 corresponding to each of a plurality of radio communication systems, and a selection switch 3_7 for switching the radio units 3_1 to 3_3 used in the multimode radio unit 3. ing.

  FIG. 1 shows an example in which a wireless unit and an antenna corresponding to each of the three types of wireless communication systems A, B, and C are provided. That is, the radio unit 3_1 and the antenna 3_4 correspond to the radio communication system A, the radio unit 3_2 and the antenna 3_5 correspond to the radio communication system B, and the radio unit 3_3 and the antenna 3_6 correspond to the radio communication system C. It corresponds. Here, it is assumed that the wireless communication systems A, B, and C conform to different wireless communication standards. Examples of different wireless communication standards include PDC (Personal Digital Cellular), GSM (Global System for Mobile Communications), IEEE 802.11a, b, g, Bluetooth, and PHS (Personal Handy-phone System).

  The multi-mode baseband processing unit 6 is configured by hardware, and performs predetermined digital baseband signal processing on the digital baseband signal. The multimode baseband processing unit 6 includes a transmission processing unit 6_1, a reception processing unit 6_2, a digital / analog converter (D / A) 6_3, an analog / digital converter (A / D) 6_4, and a clock source (CLK). 6_5. The reception processing unit 6_2 includes a low-pass filter (LPF) 6_2_1, a synchronization processing unit 6_2_2, and a demodulation processing unit 6_2_3.

  The control unit 2 sets the functions of the multimode radio unit 3 and the multimode baseband processing unit 6 to those corresponding to a desired radio communication system. The output of the communication quality estimation unit 9 is connected to the control unit 2.

  The output of the program memory 8 is connected to the inputs of the transmission processing unit 6_1 and the reception processing unit 6_2. The program memory 8 stores a program necessary for the wireless communication apparatus 1 to communicate with a plurality of wireless communication systems. In FIG. 1, programs A, B, and C corresponding to each of the three types of wireless communication systems A, B, and C are stored in the program memory 8. The wireless communication apparatus 1 executes a plurality of wireless communication systems A, B, and C by executing programs A, B, and C corresponding to the wireless communication systems A, B, and C in the transmission processing unit 6_1 and the reception processing unit 6_2. Realize communication with. Note that the content of the program is not particularly limited, and examples thereof include hardware resource configuration information of the transmission processing unit 6_1 and the reception processing unit 6_2, information indicating the content of baseband signal processing, and the like.

  The output of the reference signal library 7 is connected to the input of the synchronization processing unit 6_2_2. The reference signal library 7 stores a plurality of reference signals in advance. Here, the reference signal is obtained by performing baseband processing of another wireless communication system different from the baseband processing of the corresponding wireless communication system on the baseband known signals for the wireless communication systems A, B, and C. Signal obtained in some cases. Details of this reference signal will be described later.

  In practice, the reception signals converted into baseband signals by the radio units 3_1 to 3_3 are sequentially processed by the selection switch 3_7, the analog-digital converter 6_4, the low-pass filter 6_2_1, the synchronization processing unit 6_2_2, and the demodulation processing unit 6_2_3 to be received data. It is said. The transmission data subjected to baseband processing by the transmission processing unit 6_1 is sequentially input to the digital-analog converter 6_3 and the selection switch 3_7, and then output to one of the radio units 3_1 to 3_3 selected by the selection switch 3_7. Transmitted from the antennas 3_4 to 3_6 corresponding to the selected radio units 3_1 to 3_3.

  Next, a detailed configuration of each part will be described.

  The control unit 2 controls the functions of the multimode wireless unit 3 and the multimode baseband processing unit 6 so as to correspond to the wireless communication system used by the wireless communication device 1. Further, based on the communication quality estimation result input from the communication quality estimation unit 9, it is determined whether or not to switch the wireless communication system used for communication.

  The selection switch 3_7 of the multimode wireless unit 3 selects which wireless unit 3_1 to 3_3 is to send the output signal to the analog-to-digital converter 6_4 according to the control signal from the control unit 2, and the digital-to-analog converter 6_3. To which of the wireless units 3_1 to 3_3 the output from is sent. For example, when the control signal instructs the reception operation of the wireless communication system A, the selection switch 3_7 selects the output from the wireless unit 3_1 and sends it to the analog / digital converter 6_4. When the control signal instructs to perform the transmission operation of the wireless communication system A, the selection switch 3_7 sends the output signal from the digital / analog converter 6_3 to the wireless unit 3_1. Here, although not shown in FIG. 1, a transmission / reception duplexer is actually provided between the antennas 3_4 to 3_6 and the radio units 3_1 to 3_3. Note that the multimode wireless unit 3 may be configured such that all the wireless units 3_1 to 3_3 always operate during the above-described transmission / reception operation, or the power of the wireless units 3_1 to 3_3 that are not selected by the selection switch 3_7. The power consumption may be reduced by reducing the power consumption.

  The clock source (CLK) 6_5 can generate an operation clock corresponding to each of the plurality of wireless communication systems, and the operation clock corresponding to the wireless communication system specified by the control signal from the control unit 2 can be used. It is generated and supplied to the digital / analog converter 6_3 and the analog / digital converter 6_4.

  The analog-digital converter 6_4 converts the reception analog signal from the radio units 3_1 to 3_3 selected by the selection switch 3_7 into a reception digital signal by sampling at a predetermined rate supplied from the clock source 6_5. The digital-analog converter 6_3 converts the transmission digital signal generated by the transmission processing unit 6_1 into a transmission analog signal at a predetermined rate supplied from the clock source 6_5.

  The multi-mode baseband processing unit 6 performs baseband signal processing on transmission / reception signals. Specifically, the multimode baseband processing unit 6 reads a program corresponding to the wireless communication system indicated by the control signal input from the control unit 2 from the program memory 8, and the transmission processing unit 6_1 and the reception processing unit 6_2 Signal processing corresponding to each wireless communication system is executed by rewriting the configuration.

  That is, the transmission processing unit 6_1 is configured to be able to flexibly change the processing contents in accordance with the read program, and for the transmission data, a predetermined correspondence corresponding to the wireless communication system described in the program Performs baseband transmission processing. Here, the predetermined baseband transmission processing is processing such as error correction coding, interleaving, puncturing, primary modulation, secondary modulation, and the like. In the present invention, the detailed configuration is not particularly limited.

  Further, the reception processing unit 6_2 is configured to be able to flexibly change the processing contents according to the read program, and the reception digital signal input from the analog-digital converter 6_4 is described in the program. A predetermined baseband reception process corresponding to the wireless communication system is performed. Here, the predetermined baseband reception processing refers to processing such as filtering, time synchronization compensation, frequency synchronization compensation, error correction decoding, deinterleaving, depuncture, primary modulation, demodulation corresponding to secondary modulation, and the like. is there. In FIG. 1, only the low-pass filter 6_2_1, the synchronization processing unit 6_2_2, and the demodulation processing unit 6_2_3 are shown. However, this is shown mainly on the portion related to the present invention, and does not limit the present invention. .

  In addition to this, the reception processing unit 6_2 is instructed by the control signal input from the control unit 2 to estimate the communication quality of another wireless communication system different from the currently communicating wireless communication system. Reads the reference signal from the reference signal library 7 and inputs it to the synchronization processing unit 6_2_2.

  The low-pass filter 6_2_1 attenuates a signal component equal to or higher than the cutoff frequency among the components of the received digital signal input from the analog-digital converter 6_4. For example, the tap length can be changed according to the program read from the program memory 8, thereby enabling the filter processing corresponding to the signals of a plurality of wireless communication systems.

  When performing normal reception processing, the synchronization processing unit 6_2_2 performs synchronization processing for detecting the optimum timing for performing the reception processing on the reception signal of the wireless communication system in communication. In general, the synchronization process holds in advance a signal of a known fixed pattern in the wireless communication system in communication, performs a correlation operation between this known signal and the corresponding known signal portion of the received signal, This is realized by detecting a position where a peak appears in a certain correlation characteristic as an optimum timing.

  As described above, the synchronization processing unit 6_2_2 detects the timing of performing the reception processing on the received signal. In the present embodiment, the synchronization processing unit 6_2_2 is different from the wireless communication system in communication. It is also used to estimate the communication quality of the system. Specifically, when estimating the communication quality of a wireless communication system different from the wireless communication system in communication, the correlation between the reference signal stored in the reference signal library 7 and the received digital signal is performed, and the calculation result Are sent to the communication quality estimation unit 9. The contents of the reference signal stored in the reference signal library 7 will be described later.

  Based on the correlation value output from the synchronization processing unit 6_2_2, the communication quality estimation unit 9 determines whether or not good communication is possible when switching to the estimation target wireless communication system and performing communication. For example, as shown in FIG. 4, the peak value Cm of the correlation value is compared with a predetermined threshold value T, and the communication quality is estimated from the magnitude relationship.

  The reference signal library 7 holds a reference signal used for correlation calculation when the synchronization processing unit 6_2_2 estimates the communication quality of a wireless communication system different from the currently communicating wireless communication system.

  FIG. 2 shows an example of the contents of the reference signal library 7. In FIG. 2, the leftmost column represents a wireless communication system that can be handled by the reception processing unit 6_2, and the uppermost row represents a wireless communication system that can communicate with the multimode wireless unit 3.

  For example, the reference signal AB is a baseband known signal of the wireless communication system B that is analog-digital converted at a sampling rate corresponding to the wireless communication system A by the analog-digital converter 6_4, and then the low-pass filter 6_2_1. It shows the state of the signal when filtering with the filter characteristic corresponding to.

  Similarly, for example, the reference signal B-C is a baseband known signal of the wireless communication system C that is analog-to-digital converted at a sampling rate corresponding to the wireless communication system B by the analog-digital converter 6_4 and then wirelessly transmitted by the low-pass filter 6_2_1. It shows the state of a signal when it is filtered with a filter characteristic corresponding to the communication system B.

  Incidentally, the known signal stored as the reference signal may be a known fixed pattern portion of each wireless communication system, for example, a signal portion for synchronization processing prepared for each wireless communication system.

  That is, the reference signal library 7 includes, for the baseband known signal of each wireless communication system, analog-digital conversion processing of a wireless communication system different from the original analog-digital conversion processing and low-pass filter processing for each wireless communication system. An ideal signal waveform when low-pass filter processing is performed is stored.

  Next, the operation | movement at the time of communication quality estimation of the radio | wireless communication apparatus 1 is demonstrated using FIG. Here, as an example, a case where the communication quality of the wireless communication system B is estimated when the wireless communication apparatus 1 performs communication using the wireless communication system A will be described.

  First, the wireless communication device 1 performs communication using the wireless communication system A (step ST1). At this time, the selection switch 3_7 is connected to the radio unit A3_1, a clock corresponding to the radio communication system A is generated from the clock source 6_5, and the multimode baseband processing unit 6 operates based on the program A.

  Next, the control unit 2 outputs a control signal that instructs the multimode radio unit 3 and the multimode baseband processing unit 6 to estimate the communication quality of the radio communication system B (step ST2).

  The multi-mode wireless unit 3 that has received this control signal switches the selection switch 3_7 from the wireless unit A3_1 to the wireless unit B3_2 according to the control signal, thereby switching to a configuration capable of receiving the signal of the wireless communication system B (step ST3).

  The multimode wireless unit 3 receives the signal of the wireless communication system B by the wireless unit B3_2, and outputs the received analog signal to the analog / digital converter 6_4 via the wireless selection switch 3_7 (step ST4).

  The analog-digital converter 6_4 converts the received analog signal (that is, the signal of the radio communication system B) into a digital signal at a sampling rate corresponding to the radio communication system A, and outputs the received digital signal obtained thereby to the low-pass filter 6_2_1. (Step ST5).

  The low-pass filter 6_2_1 filters the received digital signal of the wireless communication system B with a filter characteristic corresponding to the wireless communication system A, and outputs the filtered received digital signal to the synchronization processing unit 6_2_2 (step ST6).

  The multimode baseband processing unit 6 reads the reference signal AB from the reference signal library 7 and inputs it to the synchronization processing unit 6_2_2 (step ST7).

  FIG. 3 shows a waveform of a known signal portion obtained by performing analog-digital conversion processing and low-pass filter processing of the wireless communication system A on a baseband known signal for the wireless communication system B extracted from the received signal, and a reference signal A- The superposition of the waveform of B is shown. As shown in FIG. 3, since a noise component or the like is superimposed on the received signal, it does not match the waveform of the reference signal.

  The synchronization processing unit 6_2_2 performs a correlation calculation between the known signal extracted from the received digital signal and the reference signal AB, detects a correlation peak value of the calculation result, and outputs the correlation peak value to the communication quality estimation unit 9. Output (step ST8). An example of correlation characteristics between the received digital signal and the reference signal AB is shown in FIG. In FIG. 4, a correlation peak appears at the position m. The synchronization processing unit 6_2_2 sets the correlation peak value as Cm and outputs the correlation peak value to the communication quality estimation unit 9.

  The communication quality estimation unit 9 compares the correlation peak value Cm with a predetermined threshold value T (see FIG. 4A) (step ST9).

  When the correlation peak value Cm is larger than the threshold value T (in the case of yes determination in step ST9), when communication is performed using the wireless communication system B, good communication quality is obtained. Judgment is made (step ST10). Conversely, when correlation peak value Cm is equal to or smaller than threshold value T (in the case of no determination in step ST9), it is determined that good communication quality cannot be obtained when communication is performed using radio communication system B. (Step ST11).

  Next, in step ST12, the communication quality estimation process in the case where communication is performed using the wireless communication system B is terminated.

  As a method for estimating communication quality by the communication quality estimation unit 9, as shown in FIG. 4B, a correlation peak value Cm and a correlation value of noise level (for example, an average value of other correlation values excluding the correlation peak value) and When the correlation peak value Cm is larger than the noise level by a predetermined value (for example, xdB or more (x is an arbitrary numerical value)), good communication quality is obtained when communication is performed using the wireless communication system B. You may judge that it is obtained. In this case, if the noise level is Cnoise, it may be determined whether or not 10log (Cm-Cnoise)> T is satisfied in step ST9.

  For example, when the radio wave propagation environment is a multipath environment and a plurality of correlation value peaks occur, the delay spread of the propagation path is calculated based on the correlation characteristics in step ST8, and the calculation result is predetermined in step ST9. The communication quality may be determined by determining whether it is smaller than the threshold value.

  As described above, in the wireless communication device 1 according to the present embodiment, for example, when the communication quality of the wireless communication system B is estimated during communication using the signal of the wireless communication system A, the function for the wireless communication system A is set. Of the multimode radio unit 3 and the multimode baseband processing unit 6, only the multimode radio unit 3 is switched to the function for the radio communication system B.

  The multimode baseband processing unit 6 applies the original baseband processing (that is, the baseband corresponding to the radio communication system B) to the signal of the radio communication system B converted into the baseband signal by the multimode radio unit 3. The baseband processing of the wireless communication system A different from the processing is performed. As described above, the signal subjected to the baseband processing different from the original baseband processing is the baseband processing of the corresponding wireless communication system B stored in advance in the reference signal library 7 in the synchronization processing unit 6_2_2. Correlation with a signal (reference signal AB) obtained when baseband processing of another different wireless communication system A is performed is obtained. That is, the correlation value between the ideal waveform (reference signal) stored in the reference signal library 7 and the waveform of the actual received signal is obtained by the synchronization processing unit 6_2_2. As a result, the closer the actual received waveform is to the ideal waveform, the higher the correlation value. The higher the correlation value, the better the communication quality estimation unit 9 determines the communication quality.

  Thus, during the communication with a signal of a certain wireless communication system, in estimating the communication quality of a signal of another wireless communication system different from the wireless communication system, the function of the multi-mode baseband processing unit 6 is set as the estimation target wireless communication. Even without switching to the one corresponding to the system, that is, the communication quality of the signal of the radio communication system different from the signal of the radio communication system in communication can be estimated without changing the one corresponding to the radio communication system in communication. Therefore, communication quality can be estimated in a short time.

  As described above, according to the present embodiment, when baseband processing of another wireless communication system different from the baseband processing of the corresponding wireless communication system is performed on the baseband known signal for each wireless communication system Is provided with a storage unit (reference signal library 7) for preliminarily storing a signal obtained as a reference signal, and the multimode baseband processing unit 6 is set to a function corresponding to the wireless communication system in communication, and the multimode is maintained. The wireless unit 3 is set to a function corresponding to a wireless communication system to be estimated that is different from the wireless communication system in communication, and the reception is performed by the multimode wireless unit 3 and the multimode baseband processing unit 6 in this state. The correlation between the signal of the target wireless communication system to be estimated and the reference signal is obtained, and the wireless communication system during communication is determined based on the correlation value. Wireless communication capable of estimating the communication quality of a wireless communication system different from the wireless communication system in communication in a short time by estimating the signal communication quality of the wireless communication system to be estimated different from The device 1 can be realized.

  Note that, in the above-described embodiment, the correlation calculation unit that obtains the correlation between the signal of the estimation target wireless communication system obtained by the reception processing by the multimode radio unit 3 and the multimode baseband processing unit 6 and the reference signal As described above, the case where the synchronization processing unit 6_2_2 originally provided in the reception processing unit 6_2 is used is described. However, the present invention is not limited to this, and a correlation calculation unit is provided separately from the synchronization processing unit 6_2_2. May be requested.

  In the above-described embodiment, the case where the communication quality is estimated based on the correlation value of the signal after the analog-digital conversion process and the low-pass filter process is described. However, the present invention is not limited to this, and the analog-digital conversion process is performed. The communication quality may be estimated based on the correlation value of the later signal, the correlation value of the signal after the synchronization process, or the correlation value of the signal after the demodulation process. In this case, as a matter of course, the reference signal stored in the reference signal library 7 is also made corresponding thereto. For example, when the communication quality is estimated based on the correlation value of the signal after the analog-digital conversion processing, for example, as the reference signal AB, the baseband known signal of the wireless communication system B is wirelessly transmitted by the analog-digital converter 6_4. What is necessary is just to memorize | store what shows the state of the signal when analog-digital conversion is performed at the sampling rate corresponding to the communication system A. That is, in the reference signal library 7, a signal obtained when analog-digital conversion is performed on a known signal for each wireless communication system at a sampling rate of another wireless communication system different from the original sampling rate in the analog-digital conversion unit, It may be stored as a reference signal.

  The wireless communication device and the communication quality estimation method of the present invention do not require a special circuit in the estimation of the communication quality of the switching destination wireless communication system, and do not require rewriting of digital signal processing hardware. It has an effect of being able to estimate the communication quality in a short time with a simple configuration, and is useful when applied to a software defined radio that switches a wireless communication system to be used according to the communication environment.

The block diagram which shows the structure of the radio | wireless communication apparatus which concerns on embodiment of this invention Diagram showing the contents of the reference signal library Diagram showing reference signal and received signal waveforms FIG. 5 is a diagram for explaining how to determine correlation characteristics and communication quality between a reference signal and a received signal. Flow chart showing communication quality estimation operation The figure which shows the structure of the conventional radio | wireless communications system Block diagram showing the configuration of a conventional software defined radio

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Radio | wireless communication apparatus 2 Control part 3 Multimode radio | wireless part 6 Multimode baseband process part 6_2_1 Low-pass filter (LPF)
6_2_2 Synchronization processing section 6_4 Analog to digital converter (A / D)
7 Reference signal library 9 Communication quality estimator

Claims (5)

A wireless communication device capable of communicating with a plurality of wireless communication systems,
A multi-mode wireless unit that performs wireless processing corresponding to the plurality of wireless communication systems;
A multi-mode baseband processing unit for performing baseband processing corresponding to the plurality of wireless communication systems;
A signal obtained when baseband processing of another wireless communication system different from the baseband processing of the corresponding wireless communication system is performed on the baseband known signal for each wireless communication system in advance as a reference signal. A storage unit;
A function corresponding to an estimation target radio communication system different from the radio communication system in communication with the multi mode radio unit in a state in which the multi mode baseband processing unit is set to a function corresponding to the radio communication system in communication. A control unit to be set to
Correlation calculation unit for obtaining a correlation between the reference signal and a signal of the estimation target wireless communication system obtained by reception processing by the multimode radio unit and the multimode baseband processing unit set by the control unit When,
A wireless communication apparatus comprising: a communication quality estimation unit configured to estimate a communication quality of a signal of an estimation target wireless communication system different from the wireless communication system in communication based on a correlation result obtained by the correlation calculation unit. The multi-mode baseband processing unit includes an analog-digital converter whose sampling rate is variable according to the plurality of wireless communication systems,
In the storage unit, a signal obtained when analog-digital conversion is performed on a known signal for each wireless communication system at a sampling rate of another wireless communication system different from an original sampling rate in the analog-digital conversion unit, The wireless communication apparatus according to claim 1, stored as a reference signal. The multi-mode baseband processing unit includes a low-pass filter whose filter characteristics are variable according to the plurality of wireless communication systems,
In the storage unit, a signal obtained when a low-pass filter process is performed on a known signal for each wireless communication system with a filter characteristic of another wireless communication system different from the original filter characteristic with the low-pass filter is the reference signal. The wireless communication device according to claim 1, stored as: Using the synchronization processing unit provided in the multimode baseband processing unit, the signal of the estimation target radio communication system obtained by receiving processing by the multimode radio unit and the multimode baseband processing unit, and the Find the correlation value with the reference signal,
The wireless communication apparatus according to claim 1, wherein the communication quality estimation unit estimates the communication quality based on a correlation result obtained by the synchronization processing unit. A communication quality estimation method for estimating communication quality when communication is performed in a second wireless communication system different from the first wireless communication system during communication in the first wireless communication system,
Function setting for setting the multimode radio unit to a function corresponding to the second radio communication system in a state where the multimode baseband processing unit is set to a function corresponding to the first radio communication system in communication Steps,
The reference signal obtained by performing baseband processing corresponding to the first wireless communication system on the known signal of the second wireless communication system stored in advance, and the function set in the function setting step Communication quality for estimating the communication quality of the second radio communication system based on the signal of the second radio communication system obtained by receiving processing in the multimode radio unit and the multimode baseband processing unit A communication quality estimation method comprising: an estimation step.

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