JP5319588B2 - Base station evaluation apparatus and synchronization processing method thereof - Google Patents

Description

  The present invention relates to a technique for analyzing and evaluating a signal output from a base station apparatus of a mobile communication system such as a mobile phone, and in particular, a plurality of different from a multicarrier system that performs simultaneous communication in a plurality of different frequency bands. The present invention relates to a technique for enabling efficient evaluation of a base station apparatus compatible with a multi-standard method corresponding to a communication standard.

  In a mobile communication system such as a mobile phone, communication is performed by time-division multiplexing a plurality of user signals in a frequency band (carrier frequency) for communication between a base station and a terminal, but the number of users is large. Then, it becomes impossible to multiplex with one carrier frequency. For this reason, one communication company has increased the number of available users by using a plurality of carrier frequencies.

  Correspondingly, a so-called multi-carrier method is adopted in which the base station also performs communication simultaneously using a plurality of carrier frequencies.

  In addition, with the shift of the modulation method of terminals, etc., it is also required that one communication carrier communicates with different communication standards (for example, GSM and W-CDMA), and there are a plurality of base stations to cope with this. A so-called multi-standard method is employed in which signals are transmitted simultaneously using signals of different communication standards. In recent years, a base station apparatus compatible with multi-carrier and multi-standard is required.

  Therefore, a wireless standard for operating a plurality of systems in the same frequency band is defined as Multi-Standard Radio (MSR) Base Station (BS) in 3GPP TS 37.104. The frequency band is as shown in FIG.

  In FIG. 13, as an example of a multi-standard, among the frequency bands defined by the output (Downlink) of the base station, for example, in the frequency bands of 869 to 894 MHz and 925 to 960 MHz, MSR and E-UTRA (LTE) And three different systems are used: UTRA (W-CDMA) and GSM / EDGE.

  Therefore, in order to evaluate the base station apparatus that uses the carrier frequencies in the frequency bands of 869 to 894 MHz and 925 to 960 MHz for communication, it is necessary to measure each carrier frequency signal according to a different system. However, the conventional evaluation apparatus for mobile communication devices, for example, as described in the following Patent Document 1, selectively receives a signal of one carrier frequency (single carrier) and performs processing necessary for the evaluation. Therefore, when performing multicarrier measurement, a series of tests necessary for evaluation of one carrier frequency is performed, and then the next carrier frequency is transferred to perform the same test. There is a problem that it takes time and labor.

  In addition, due to the measurement principle, there is a problem that it is impossible to grasp the mutual influence between bands when a plurality of carrier frequencies are used simultaneously.

JP 2007-19741 A

  As a technique for solving the above problem, signal components of a plurality of carrier frequencies to be measured are collectively received by a heterodyne wideband receiver and converted into an intermediate frequency band, and the waveform of the signal in the intermediate frequency band A method is conceivable in which data is acquired and stored for a certain period of time, and signal components of individual carrier frequencies are extracted from the stored waveform data and analyzed.

  However, when actually configuring the evaluation device of the above method, if the measurement conditions can be arbitrarily set for each of a plurality of carrier frequencies to be measured and each frequency component, each signal component in the intermediate frequency band of the receiving unit Therefore, a technique for efficiently performing symbol synchronization processing and frame synchronization processing is required.

  The present invention solves this problem and, in an apparatus for evaluating a base station apparatus compatible with multi-carrier and multi-standard, according to a set carrier frequency and measurement conditions, a symbol for each signal component in an intermediate frequency band An object of the present invention is to provide a base station evaluation apparatus and a synchronization processing method capable of efficiently performing synchronization processing and frame synchronization processing.

In order to achieve the above object, a base station evaluation apparatus according to claim 1 of the present invention comprises:
Wideband reception that receives a signal including a plurality of different carrier frequencies used for communication by the base station apparatus to be evaluated, mixes the signal with a local signal, and converts the signal into an intermediate frequency band that covers the plurality of different carrier frequencies Section (22), an A / D converter (23) for sampling the signal output from the broadband receiving section and converting it into digital waveform data, and waveform data for storing the waveform data converted by the A / D converter A reception storage unit (21) having a memory (24) and acquiring waveform data of a signal output by the base station device at a predetermined time;
Analyzing the waveform data stored in the reception storage unit, detecting a signal inserted in a desired time slot in each frame of the plurality of different carrier frequencies, and a modulation scheme set in advance for the slot, An analysis unit (25) that performs measurement based on measurement items;
With respect to the analysis unit, set for setting information including the modulation scheme information for each slot in a frame of the plurality of different carrier frequencies, respectively, and each said carrier frequency, symbol rate information, the frame phase information and the measurement item information between the carrier A base station evaluation device comprising a unit (30),
The analysis unit
Reads waveform data stored in the reception storage unit, with respect to the read-out waveform data, performs a frequency conversion process by a local signal of a frequency corresponding to the signal component of the plurality of different carrier frequencies, the plurality of different Signal extraction means (26) for converting each signal component of the carrier frequency into a baseband,
Symbol synchronization processing means (27) for performing symbol synchronization processing on each signal component converted into a baseband by the signal extraction means based on the modulation scheme information and generating a data signal sequence;
Frame synchronization processing means (28) for performing frame synchronization processing on the data signal obtained by the symbol synchronization processing and determining the position of the frame and the position of each slot;
Furthermore, the symbol synchronization processing means and the frame synchronization processing means share the synchronization information obtained by the symbol synchronization processing and the frame synchronization processing for the signal component for one carrier transmitted from the base station apparatus to be evaluated for each carrier. And performing synchronization processing on signal components for other carriers based on the common synchronization information and the modulation scheme information, symbol rate information, and inter-carrier frame phase information for each carrier. To do.

In addition, the synchronization processing method of the base station evaluation apparatus of the present invention,
Wideband reception that receives a signal including a plurality of different carrier frequencies used for communication by the base station apparatus to be evaluated, mixes the signal with a local signal, and converts the signal into an intermediate frequency band that covers the plurality of different carrier frequencies Section (22), an A / D converter (23) for sampling the signal output from the broadband receiving section and converting it into digital waveform data, and waveform data for storing the waveform data converted by the A / D converter A reception storage unit (21) having a memory (24) and acquiring waveform data of a signal output by the base station device at a predetermined time;
The analyzes waveform data stored in the reception storage unit, performs the extraction processing of the base band components of a plurality of different carrier frequencies each signal, the symbol synchronization for the signal component of the base band and frame synchronization, the frame An analysis unit (25) that detects a data signal inserted in a desired time slot and performs measurement based on a modulation scheme and measurement items set in advance for the slot;
With respect to the analysis unit, to set the information including the modulation scheme information for each slot in a frame of the plurality of different carrier frequencies, respectively, and each said carrier frequency, symbol rate information, and a frame phase information and the measurement item information between the carrier A synchronization processing method in the analysis unit of the base station evaluation device comprising a setting unit (30),
Performing symbol synchronization processing on a signal component of one carrier and frame synchronization processing on a data signal sequence obtained by the symbol synchronization processing (S22, S32);
The synchronization information obtained by the symbol synchronization processing and the frame synchronization processing for the signal component for one carrier is set as the common synchronization information for each carrier, and the common synchronization information and the modulation scheme information and symbol rate information for each carrier. And a step (S24, S34) of performing symbol synchronization processing and frame synchronization processing on signal components for other carriers based on inter-carrier frame phase information.

  As described above, in the present invention, in consideration of the commonality of clocks used by the base station apparatus to be evaluated for symbol data generation, the symbol synchronization obtained for one carrier with respect to the signal component of each carrier extracted by the analysis unit. Information and frame synchronization information as common synchronization information, and symbols for signal components for other carriers based on this common synchronization information, modulation scheme information, symbol rate information, and inter-carrier frame phase information for each carrier Since the synchronization process and the frame synchronization process are performed, the synchronization process for the signal component of each carrier can be performed very efficiently.

Configuration diagram of an embodiment of the present invention The figure for demonstrating the operation | movement of the principal part of embodiment. The figure which shows the structure of the principal part of embodiment. The figure which shows the specific example of the frame phase information between carriers of embodiment The figure which shows the specific example of the frame phase information between carriers of embodiment The flowchart for demonstrating the operation | movement of the principal part of embodiment. The figure for demonstrating the operation | movement of the principal part of embodiment. The figure for demonstrating the operation | movement of the principal part of embodiment. The flowchart for demonstrating the operation | movement of the principal part of embodiment. The figure for demonstrating the operation | movement of the principal part of embodiment. The flowchart for demonstrating the operation | movement of the principal part of embodiment. The flowchart for demonstrating the operation | movement of the principal part of embodiment. The figure showing the relationship between the frequency band which a base station apparatus uses, and the system used for communication

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows the configuration of a base station evaluation apparatus 20 to which the present invention is applied.

  In FIG. 1, the reception storage unit 21 includes a wideband reception unit 22, an A / D converter 23, and a waveform data memory 24.

  The wideband receiving unit 22 has a wide reception band including a plurality of different carrier frequencies used for communication by the evaluation target base station apparatus 1 corresponding to multicarrier and multistandard (for example, 869 to 894 MHz, 925 to 960 MHz as described above). Frequency band), and the signal components of a plurality of carrier frequencies designated by the setting unit 30 described later are collectively received among the signals in the reception band.

Broadband receiving unit 22 includes a mixer 22a, includes a local signal generator 22b and the intermediate frequency filter 22c, and a local signal _{S LOC} output from the input signal _{S IN} and the local signal generator 22b to mix fed to the mixer 22a, One of the sum and difference components (here, the difference component) is extracted by the intermediate frequency filter 22c, and the band of the intermediate frequency filter 22c may be designated as a measurement target. It has a width W necessary to pass all the signal components of the carrier frequency.

  For example, when there is a possibility that the entire reception band of 925 to 960 MHz may be designated as a measurement target, a width of at least 960-925 = 35 MHz is required.

The frequency _{f LOC} of the local signal _{S LOC,} if the passing center frequency of the intermediate frequency filter 22c and _{f IF,} actually all _{f IF} ± signal components of the carrier frequency specified as the measurement object by setting section 30 Any value can be used as long as it is heterodyne converted into the intermediate frequency band of W / 2. | (925 + 960) / 2−f so that the signal components of the entire reception band of 925 to 960 MHz can be collectively converted into the intermediate frequency band. _{If LOC} | = f _IF , any carrier frequency within the reception band can be specified with a fixed local frequency f _LOC . Taking numerical examples, f _IF = 200 MHz and f _LOC = 742.5 MHz (or 1142.5 MHz).

  However, the carrier frequency (channel) to be measured is an item that is arbitrarily specified by the measurer. If the specified carrier is concentrated only on one end of the reception band, the frequency component of the signal component is converted to the intermediate frequency. This is concentrated on the edge of the pass band of the filter 22c, which is susceptible to the characteristics of the filter edge (amplitude and phase fluctuations) and is undesirable.

  In order to prevent this, it is possible to set the local frequency based on the carrier frequency specified by the measurer, but in addition to the above-mentioned carrier frequency, in addition to the slot designation and measurement item designation operation, If a local frequency setting operation is added, the operation becomes very complicated.

Therefore, in this base station evaluation apparatus 20, the reception frequency control means 50 automatically sets the frequency f _LOC (that is, the reception frequency) of the local signal output from the local signal generator 22b.

The reception frequency control means 50 obtains a minimum frequency range f1 to f2 necessary for measurement based on each carrier frequency set by the setting unit 30 and measurement item information, and a center frequency (f1 + f2) / f of the frequency range. The frequency f _{LOC of the} local signal is set so that 2 is converted to the passing center frequency f _IF in the intermediate frequency band.

That is, for easy understanding, if the lower heterodyne having a local frequency lower than the input signal frequency is used, the lower limit frequency f1 and the upper limit frequency f2 are determined according to the upper and lower limits of the carrier frequency arbitrarily specified by the measurer and the measurement item. Whereas
f _LOC = (f1 + f2) / 2−f _IF
Is obtained, and the frequency information is set in the local signal generator 22b to generate a local signal having the frequency f _LOC . For upper heterodyne,
f _LOC = (f1 + f2) / 2 + f _IF
Find and set the local frequency at which

  The lower limit frequency f1 and the upper limit frequency f2 are determined in consideration of the case where the measurement item of adjacent channel leakage is specified for the lower limit and the upper limit carrier frequency.

  As a result, for example, as shown in FIG. 2A, even when the carrier frequencies fc1 to fcn to be measured are biased toward the low frequency side of the entire reception band, the intermediate frequency as shown in FIG. The signals are gathered and output in the vicinity of the center of the band, and are not easily affected by fluctuations in the amplitude characteristics and phase characteristics of the filter edges. FIG. 2 shows the case of the lower heterodyne. However, in the case of the upper heterodyne, the arrangement of the signal components converted to the intermediate frequency band is inverted with respect to the case of FIG.

The signal S _IF converted to the intermediate frequency band is sampled by the A / D converter 23 at a predetermined frequency (more than twice the upper limit frequency of the intermediate frequency band), converted into a digital signal sequence D (k), and a waveform. It is stored in the data memory 24 for a certain time.

  The analysis unit 25 includes a signal extraction unit 26, a symbol synchronization unit 27, a frame synchronization unit 28, and an analysis unit 29. The analysis unit 25 analyzes the waveform data stored in the waveform data memory 24 of the reception storage unit 21, and each carrier Each frequency signal component is converted into a baseband band and extracted. The extracted baseband component is subjected to symbol synchronization processing, frame synchronization processing, and the like, and the symbol position and frame position are determined by the synchronization processing. A signal inserted in a desired time slot is detected from the signal, signal demodulation and measurement are performed based on a modulation method and measurement items set in advance for the slot, and the result is displayed on the display unit 40. Let

  The signal extraction unit 26 reads the waveform data stored in the reception storage unit 21, performs a frequency conversion process on the read waveform data using local signals having frequencies corresponding to signal components of a plurality of carrier frequencies, Each signal component of a plurality of carrier frequencies is converted into a baseband. This frequency conversion processing is performed using quadrature detection processing in order to obtain two quadrature baseband components. However, as will be described later, when the quadrature component is detected in advance in the reception storage unit 21, the signal extraction means 26 is simple. It can be composed of a simple single-phase frequency converter.

For example, as shown in FIG. 3, the signal extraction means 26 includes two sets of mixers (multipliers) 26a and 26b, a local signal generator 26c, a 90-degree phase shifter 26d, baseband filters 26e and 26f, and a baseband signal. The memory 26g and the local frequency switching means 26h are configured, and the local signals L ₀ and L ₉₀ having the frequency f _LL generated by the local signal generator 26c and the 90-degree phase shifter 26d are supplied to the mixers 26a and 26b. baseband filter 26e from the mixer output, converts the signal component having a center frequency _{f LL} signal Ii baseband (e.g. 0～6MHz), to Qi through 26f, and stores it in baseband signal memory 26g .

Further, the local frequency control unit 26h is configured to output a local signal to be output by the local signal generator 26c based on each carrier frequency to be measured designated by the setting unit 30 described later and the frequency of the local signal _{SLOC in} the reception storage unit 21. The frequency f _LL of the signal L ₀ is sequentially changed (note that the signal handled by the signal extraction means 26 is a digital data string, so the mixers 26a and 26b, the local signal generator 26c, the 90-degree phase shifter 26d, and the baseband Each component such as the filters 26e and 26f is realized by an arithmetic process equivalent to its function).

  The baseband components Ii and Qi for each carrier converted into the baseband band by the signal extraction unit 26 are sampled by the symbol synchronization unit 27 at a period corresponding to the modulation scheme information and symbol rate (or bit rate) information, and are subjected to symbol synchronization processing. Is made. The symbol synchronization process is a process for synchronizing the symbol clock on the base station apparatus 1 side and the symbol clock on the apparatus side, and the sampled signal component Iis for one carrier transmitted from the evaluation target base station apparatus. The phase shift processing is performed so that the position (symbol position) on the IQ orthogonal coordinates determined by Qis becomes the reference position determined by the modulation method.

  For example, when the modulation method is QPSK and a predetermined symbol rate, the positions of (1, 1), (1, −1), (−1, −1), and (−1, 1) on the IQ orthogonal coordinates are symbols. If the position is a reference and synchronization is established, the symbol position determined by each baseband signal component Iis, Qis transitions between these four reference positions at a time interval corresponding to the predetermined symbol rate. (Strictly speaking, it varies from the reference position due to the influence of noise, etc.).

  Therefore, for example, the baseband signal components I1 and Q1 obtained for the first carrier are sampled at intervals corresponding to the predetermined bit rate, and the error between the symbol position determined by the sampled signal components I1s and Q1s and the reference position is determined. Symbol synchronization is completed by determining the sampling timing for the baseband signal components I1 and Q1 (symbol clock recovery) so that the error is minimized. By this processing, symbol data corresponding to each symbol position can be correctly acquired. In the case of the modulation scheme QPSK, 2-bit symbol data (00), (01), (10 ) And (11).

  Actually, the sampling timing when acquiring the baseband component by the signal extraction processing is not always synchronized with the symbol timing of the baseband component, so the interpolation processing is performed on the signal, and the interpolation processing is performed. Sampling is performed on the signal obtained in step (1) to determine the best sampling timing with a small error.

  Then, considering that the symbol synchronization means 27 generates symbol data using a common clock on the base station apparatus 1 side, the synchronization information (symbol information required for the symbol synchronization processing obtained for the first carrier ( Sampling timing information) is used as common synchronization information for each carrier, and symbol synchronization processing is performed on signal components for other carriers based on the common synchronization information, modulation scheme information and symbol rate information for each carrier.

  That is, for example, when the modulation method of the second carrier is QPSK and the symbol rate is 1/4 of the first carrier, the symbol of the first carrier out of the baseband signal components I2 and Q2 obtained for the second carrier. Focusing on the signal components I2s and Q2s that are synchronized and finally sampled at the same timing as the signal components I1s and Q1s, the four samples are sampled in time series at a rate of one set, and the error from the reference position is the same as above. Ask for. Since one set is extracted from four sets, four types of signal sequences can be obtained. A signal sequence having the smallest error is obtained from them, and symbol data for the second carrier is acquired from the signal sequence.

  Further, for example, when the modulation scheme of the third carrier is 16QAM scheme having 16 reference symbol positions on the IQ plane and the symbol rate is, for example, twice that of the first carrier, the modulation scheme is 4 times and the symbol rate is 2 Therefore, the sampling rate is 8 times that of the first carrier.

  In this case, among the baseband signal components I3 and Q3 obtained for the third carrier, the signal components I3s and Q3s having the same timing as the signal components I1s and Q1s that are finally sampled in synchronization with the symbols of the first carrier, and The signal sequence consisting of the signal components I3s ′ and Q3s ′ at seven timings that divide the sampling interval into eight is sampled, and symbol data in units of 4 bits for the third carrier is obtained from the signal sequence.

  As described above, since the synchronization information obtained by the symbol synchronization processing for one carrier is commonly used for the symbol synchronization processing for other carriers, the symbol synchronization processing for each carrier is performed in a very short time. be able to.

  Note that the symbol data obtained by the above processing is output to the frame synchronization means 28 as a data signal sequence having a predetermined bit width (either one bit width or a plurality of bit widths), for example.

The frame synchronization processing means 28 performs frame synchronization processing on the data signal sequence obtained by the symbol synchronization processing, and determines the position of the frame (start position) and the position of each slot.
This frame synchronization processing is performed by finding a predetermined pilot pattern inserted at the head position of each frame from the data signal sequence. If the head position is specified, the position of each slot is determined from the known frame structure. Can also be identified.

  Similarly to the symbol synchronization means 27, the frame synchronization means 28 uses the frame synchronization information (timing information at the head position) obtained by the frame synchronization processing for the data signal sequence obtained for one carrier as common synchronization information. Frame synchronization processing for the data signal sequence of the carrier, inter-carrier frame phase information (evaluation device) for specifying the common synchronization information and a frame position shift between carriers output in parallel by the base station device 1 to be evaluated. On the other side).

Frame phase information between the carriers, for example, as in FIG. 4 (a), a certain metric each carrier each frame number Nf1~Nfn at the timing _{T 0} and symbol number Ns1～Nsn, shown in FIG. 4 (b) It becomes information like this. Further, for example, as shown in (a) of FIG. 5, in certain information such as in FIG. 5 (b) showing the time until the first frame of each carrier in each symbol number Cs1~Csn from the measurement reference timing T ₀ Good.

  If such inter-carrier frame phase information is known, if the start position can be specified by frame synchronization processing for one carrier, the start position of the frame for another carrier can be easily detected. Further, as described above, since the signal component for each carrier has a data signal sequence of a symbol clock composed of a common clock source, it is possible to express the frame shift in symbol units as described above. It is easy to specify timing.

  Note that the above information can also be used when the frame positions between carriers are the same. That is, in this case, in the information of FIG. 4, the frame number and the symbol number of each carrier are the same, and in the information of FIG. 5, the number of symbols representing the time to the first frame of each carrier is equal.

  In this way, the frame synchronization means 28 specifies the frame position and slot position for each carrier, and the information is sent to the analysis means 29 together with the data signal sequence.

  The analysis means 29 detects a signal inserted in a desired time slot in the frame for each carrier, performs measurement based on a modulation scheme and measurement items set in advance for the slot, and displays the result. Displayed on the unit 40.

  The setting unit 30 displays the information necessary for setting on the display unit 40 in accordance with the operation of the operation unit 45, while causing the analysis unit 25 to display modulation scheme information and symbol rate for each slot in the frame of each carrier frequency. This is for setting information, inter-carrier frame phase information, measurement item information, and the like.

  The information specified here includes the carrier frequency, the frame and slot of the signal component of the carrier frequency, the modulation method such as GMSK and 8PSK, the symbol rate (bit rate), Power, Modulation (modulation error), and ORFS (adjacent channel leakage). ) And the like, and the demodulation processing based on the specified modulation method is performed on the desired slot of the desired frame of the signal component of the designated carrier frequency, and the measurement of the designated item is performed on the result. Let it be done. Further, it is auxiliary information necessary for efficiently performing the symbol synchronization processing and frame synchronization processing described above.

  The analysis unit 25 refers to the information specified by the setting unit 30, and converts the signal components of the carrier frequencies fc1, fc2,... (Actually converted to the intermediate frequency band from the waveform data stored in the waveform data memory 24). Baseband components (I1, Q1), (I2, Q2),... Are extracted, data signal sequences are generated by symbol synchronization processing, and frame and slot positions are identified by frame synchronization processing. The signal inserted in the desired time slot in the frame for each carrier is detected by analysis processing, and various measurement processes are performed based on the modulation method and measurement items specified for that slot, and the results are displayed. Displayed on the unit 40.

  In addition, the reception frequency control means 50 described above determines the carrier frequencies fc1, fc2,... Specified by the setting unit 30, the modulation scheme (specifies the occupied bandwidth), and the presence / absence of adjacent channel leakage. Determine the reception frequency.

  FIG. 6 is a flowchart showing the processing procedure of the reception frequency control means 50. The reception frequency control process of the embodiment will be described below based on this flowchart.

  First, it is checked whether there is an adjacent channel leakage (ORFS or ACLR) item in the measurement item of the highest frequency among the carrier frequencies (channels) designated as the measurement object by the setting unit 30 (S1).

  When there is an adjacent channel leakage item, as shown in FIG. 7A, the upper limit frequency f2 ′ required for the measurement of the highest carrier frequency is set to the frequency width Wa required for the adjacent channel leakage measurement and a predetermined value. The upper limit frequency f2 is determined by adding the margin α (S2). If there is no adjacent channel leakage item, as shown in FIG. 7B, a predetermined margin β is added to the upper limit frequency f2 ′ required for the measurement of the highest carrier frequency, and the upper limit frequency is set. Let it be f2 (S3).

  Next, it is checked whether there is an adjacent channel leakage (ACLR or ORFS) item in the measurement item of the lowest frequency among the carrier frequencies (channels) designated as the measurement object by the setting unit 30 (S4).

  If there is an item of adjacent channel leakage, as shown in FIG. 8A, the frequency width Wa required for measurement of adjacent channel leakage from the lower limit frequency f1 ′ required for measurement of the minimum frequency of the carrier frequency. Then, the lower limit frequency f1 is determined by subtracting the value obtained by adding the predetermined margin α (S5). When there is no adjacent channel leakage item, as shown in FIG. 8B, a predetermined margin β is subtracted from the lower limit frequency f1 ′ necessary for measurement of the lowest carrier frequency to obtain the lower limit frequency f1. (S6).

Then, the center value fm = (f1 + f2) of the lower limit frequency f1 and an upper frequency limit f2 / 2 The calculated (S7), the local frequency _{f LOC} for the center value fm is converted to central pass frequency _{f IF} of the intermediate frequency band _Is calculated by f _LOC = fm−f _IF (or f _LOC = fm + f _IF ), and the frequency information is set in the local signal generator 22b (S8).

  As a result of the above processing, the waveform data memory 24 converts the signal including the signal component of the carrier frequency specified as the measurement target into the intermediate frequency band, and stores the waveform data of the signal for a predetermined time in the waveform data memory 24. .

  The waveform data stored in the waveform data memory 24 is subjected to signal extraction processing by the analysis unit 25 at a predetermined timing.

That is, assuming that the frequency of the carrier signal to be measured is fc1 to fcn and the lower heterodyne is used in the reception storage unit 21, each carrier frequency fc1 to fcn is a frequency (fc1−f) in the intermediate frequency band. _LOC ) to (fcn-f _LOC ).

Therefore, in the signal extraction process by the signal extraction means 26, as shown in FIG. 9, the variable i designating the carrier is initialized to 1 (S11), and the frequencies f _LL of the local signals L ₀ and L ₉₀ are set to (fci−f). _LOC ) is set (S12), and quadrature detection processing is performed on the waveform data stored in the waveform data memory 24.

Accordingly, as shown in FIG. 10A, the signal component centered on the frequency (fci−f _LOC ) in the intermediate frequency band is centered on the frequency 0 as shown in FIGS. 10B and 10C. Are converted into baseband components Ii and Qi, and the orthogonal baseband components Ii and Qi are stored at addresses corresponding to the corresponding variable i (S13).

  Then, the processes of S12 and S13 are repeated for the carrier frequency to be measured (S14 and S15), and baseband components (I1, Q1) to (In, Qn) for each carrier are obtained.

  The baseband signal component for each carrier thus obtained is subjected to symbol synchronization processing by the symbol synchronization means 27.

  FIG. 11 is a flowchart showing the procedure of this symbol synchronization process. Hereinafter, the procedure will be described.

  First, a variable i designating a carrier (channel) is initialized to 1, the above-described normal symbol synchronization processing (symbol clock recovery) is performed on the baseband components I1 and Q1 for the first carrier, and the baseband is obtained. The component is sampled at an optimal timing to generate a data signal sequence D1 (S21, S22).

  Next, i is incremented by 1, and the information of the optimum sampling timing (symbol clock phase) obtained by the first symbol synchronization processing is changed to the common synchronization information for the baseband components I2 and Q2 for the next carrier. As a result, an optimum sampling timing is obtained using information such as a modulation system and a symbol rate, and sampling is performed on the baseband components I2 and Q2 to generate a data signal sequence D2 (S23, S24).

  Thereafter, processing S23 and S24 are repeated, symbol clock synchronization processing is performed for all carriers, and data signal sequences D1 to Dn are generated (S25).

  The above example is for the case where the symbol timings of all the carriers are synchronized on the base station apparatus 1 to be evaluated (the symbol clock period is an integer multiple), but the communication standards are different. If there is a channel that does not have symbol timing synchronization, the common synchronization information is obtained for each communication standard, and the symbol synchronization process is performed by using the common synchronization information for the same communication standard. Increase efficiency.

Next, the frame synchronization processing shown in FIG.
That is, first, a variable i for specifying a carrier (channel) is initialized to 1, and the above-described normal frame synchronization processing (first detection by a pilot pattern) is performed on the data signal sequence D1 for the first carrier. Synchronization information indicating the frame head position is obtained (S31, S32).

  Next, i is incremented by 1, and the synchronization information indicating the frame head position of the data signal sequence D2 for the next carrier is replaced with the common synchronization information obtained by the processing of the data signal sequence D1 and the inter-carrier frame described above. It specifies using phase information (S33, S34).

  Thereafter, processing S33 and S34 are repeated, frame synchronization processing is performed for all carriers, and synchronization information indicating frame head positions for the respective data signal sequences D1 to Dn is generated (S35).

  The above example is a case where inter-carrier frame phase information for all carriers is given on the base station apparatus 1 to be evaluated, but includes a channel whose frame length varies and the phase cannot be specified. In this case, the normal frame synchronization processing is performed for the channel, but the pilot pattern detection processing is unnecessary for the channel for which the inter-carrier frame phase is specified, and the frame synchronization processing can be made more efficient.

In the above example,
(A) Processing for generating data signal sequence D1 by symbol synchronization processing for one carrier (b) Processing for generating data data signal sequences D2 to Dn for other carriers (c) Frame synchronization processing for data signal sequence D1 (d ) Processing was performed in the order of frame synchronization processing for the data signal sequences D2 to Dn.
(A) Processing for generating data signal sequence D1 by symbol synchronization processing for one carrier (b) Frame synchronization processing for data signal sequence D1 (c) Processing for generating data data signal sequences D2 to Dn for other carriers (d ) You may perform in order of the frame-synchronization process with respect to data signal sequence D2-Dn.

  The analysis means 29 measures the preset items for the frame data for each carrier obtained by the symbol synchronization process and the frame synchronization process, and displays the measurement results.

  In the above embodiment, the reception storage unit 21 controls the reception frequency so that the center of the upper limit frequency and the lower limit frequency necessary for the measurement coincides with the passing center frequency of the intermediate frequency band, but the upper limit frequency necessary for the measurement. To the lower limit frequency, the baseband component of each carrier can be extracted.

Further, in the above embodiment, the quadrature detection processing is used in the signal extraction means 26 in order to convert the signal component of each carrier into quadrature baseband, but the quadrature two-phase type frequency conversion processing is performed in the reception storage unit 21. The received signal may be converted into orthogonal components I _IF and Q _IF in the intermediate frequency band and stored in the waveform data memory 24. In this case, the signal extraction unit 26 stores the waveform in the waveform data memory 24. Read out the quadrature components I _IF and Q _IF , respectively, to make the signal input of each of the single-phase type frequency converters (for example, the mixers 26a and 26b in FIG. 3 independent), and to provide both mixers 26a and 26b with in-phase local signals The local frequency of the frequency converter is sequentially changed according to each carrier, and the signal component of each carrier is centered on the frequency 0. Baseband component (I1, Q1) ~ (In, Qn) may be sequentially converted to.

  DESCRIPTION OF SYMBOLS 20 ... Base station evaluation apparatus, 21 ... Reception storage part, 22 ... Broadband receiving part, 22a ... Mixer, 22b ... Local signal generator, 22c ... Intermediate frequency filter, 23 ... A / D converter , 24... Waveform data memory, 25... Analysis unit, 26... Signal extraction means, 27... Symbol synchronization means, 28. Display unit 45 .. operation unit 50 .. reception frequency control means

Claims (2)

Wideband reception that receives a signal including a plurality of different carrier frequencies used for communication by the base station apparatus to be evaluated, mixes the signal with a local signal, and converts the signal into an intermediate frequency band that covers the plurality of different carrier frequencies Section (22), an A / D converter (23) for sampling the signal output from the broadband receiving section and converting it into digital waveform data, and waveform data for storing the waveform data converted by the A / D converter A reception storage unit (21) having a memory (24) and acquiring waveform data of a signal output by the base station device at a predetermined time;
Analyzing the waveform data stored in the reception storage unit, detecting a signal inserted in a desired time slot in each frame of the plurality of different carrier frequencies, and a modulation scheme set in advance for the slot, An analysis unit (25) that performs measurement based on measurement items;
With respect to the analysis unit, set for setting information including the modulation scheme information for each slot in a frame of the plurality of different carrier frequencies, respectively, and each said carrier frequency, symbol rate information, the frame phase information and the measurement item information between the carrier A base station evaluation device comprising a unit (30),
The analysis unit
Reads waveform data stored in the reception storage unit, with respect to the read-out waveform data, performs a frequency conversion process by a local signal of a frequency corresponding to the signal component of the plurality of different carrier frequencies, the plurality of different Signal extraction means (26) for converting each signal component of the carrier frequency into a baseband,
Symbol synchronization processing means (27) for performing symbol synchronization processing on each signal component converted into a baseband by the signal extraction means based on the modulation scheme information and generating a data signal sequence;
Frame synchronization processing means (28) for performing frame synchronization processing on the data signal obtained by the symbol synchronization processing and determining the position of the frame and the position of each slot;
Furthermore, the symbol synchronization processing means and the frame synchronization processing means share the synchronization information obtained by the symbol synchronization processing and the frame synchronization processing for the signal component for one carrier transmitted from the base station apparatus to be evaluated for each carrier. And performing synchronization processing on signal components for other carriers based on the common synchronization information and the modulation scheme information, symbol rate information, and inter-carrier frame phase information for each carrier. Base station evaluation device. Wideband reception that receives a signal including a plurality of different carrier frequencies used for communication by the base station apparatus to be evaluated, mixes the signal with a local signal, and converts the signal into an intermediate frequency band that covers the plurality of different carrier frequencies Section (22), an A / D converter (23) for sampling the signal output from the broadband receiving section and converting it into digital waveform data, and waveform data for storing the waveform data converted by the A / D converter A reception storage unit (21) having a memory (24) and acquiring waveform data of a signal output by the base station device at a predetermined time;
The analyzes waveform data stored in the reception storage unit, performs the extraction processing of the base band components of a plurality of different carrier frequencies each signal, the symbol synchronization for the signal component of the base band and frame synchronization, the frame An analysis unit (25) that detects a data signal inserted in a desired time slot and performs measurement based on a modulation scheme and measurement items set in advance for the slot;
With respect to the analysis unit, to set the information including the modulation scheme information for each slot in a frame of the plurality of different carrier frequencies, respectively, and each said carrier frequency, symbol rate information, and a frame phase information and the measurement item information between the carrier A synchronization processing method in the analysis unit of the base station evaluation device comprising a setting unit (30),
Performing symbol synchronization processing on a signal component of one carrier and frame synchronization processing on a data signal sequence obtained by the symbol synchronization processing (S22, S32);
The synchronization information obtained by the symbol synchronization processing and the frame synchronization processing for the signal component for one carrier is set as the common synchronization information for each carrier, and the common synchronization information and the modulation scheme information and symbol rate information for each carrier. And a step (S24, S34) of performing symbol synchronization processing and frame synchronization processing on signal components for other carriers based on inter-carrier frame phase information (S24, S34). .

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