JP5752063B2 - Signal generating apparatus, test system, and signal generating method - Google Patents

Description

  The present invention relates to a signal generator for inserting test signal data into each physical channel of a signal having a format in which one frame is composed of a plurality of physical channels and outputting various signal insertion patterns for the physical channels. Further, the present invention relates to a technique for enabling easy correspondence with a small memory capacity configuration and changing a signal to be inserted into a specific physical channel during signal transmission.

  In recent years, in mobile terminals represented by mobile phones and smartphones, in addition to conventional communication methods such as CDMA, GSM (registered trademark), and PHS that realize a telephone function and a mail transmission / reception function in order to enhance the convenience, GPS satellites In order to test the baseband communication according to the protocols defined by these many communication methods, including the radio wave reception function of Bluetooth, the function of performing communication with many different communication methods, including Bluetooth Is required for a predetermined number of frames in order from the lower layer, and is orthogonally modulated to be converted into a high-frequency signal in the frequency band assigned to the communication method and output.

  However, in a configuration in which a signal for a plurality of frames is constructed in real time in order from the lower layer according to a protocol dedicated to the communication method, and then converted into a high-frequency signal and output, high-speed signal construction processing is possible for each communication method. A system is required, and the apparatus configuration is expensive and large.

  As a technique for solving this problem, signal data that can be inserted into each physical channel (called a slot depending on the communication method) constituting a frame of each communication method is generated in advance and stored in a memory, and the specified communication method In accordance with the transmission timing of the physical channel used in the frame, signal data designated in advance for the physical channel is read from the memory and inserted, and a signal comprising one frame with a plurality of physical channels is output. There is a technique for outputting a high-frequency modulated signal obtained by orthogonally modulating a signal.

  A technique for outputting a signal configured by reading out signal data stored in a memory as described above from the beginning in synchronization with an external trigger is disclosed in, for example, the following Patent Document 1.

JP 2003-196580 A

  With respect to the signal reading technique of the signal generator configured as described above, if the insertion pattern of the signal data for each physical channel of one frame is the same for each frame and the frame is simply transmitted repeatedly for a plurality of frames, it corresponds to one frame. It is sufficient to store signal data in a time series and read them out in order and cyclically, but in order to simulate a more realistic communication environment, each slot or multiple frame interval is used for each slot. The signal data insertion pattern is also required to be varied. In this case, the signal pattern repetition period is inevitably long, and a huge amount of memory is required to store signal data for one period.

  As a technique for solving this problem and adapting to various transmission patterns, a table (sequence table) in which read addresses of signal data to be inserted into each physical channel for the entire transmission signal are sequentially written is used. There is a way.

  In a simple example, as shown in FIG. 4, a signal in which one physical frame is composed of three physical channels, signal data A is inserted into the first physical channel among the physical channels, and the second physical channel is inserted. Three different types of signal data B1 to B3 are sequentially inserted into the channel, and two different types of signal data C1 and C2 are alternately inserted into the third physical channel in a pattern of 6 frames (18 physical channels). It is necessary to prepare a table in which read addresses for the minute are written and read them sequentially and cyclically. In an actual example, when a signal composed of 20 slots in one frame is divided into patterns for each slot and transmitted for 100 frames as in the LTE system, it is necessary to write 2000 read addresses, Complicated work is required.

  Further, in the pattern fixed as described above, it is impossible in principle to change the signal data of a specific physical channel to another signal data while transmitting a series of signals. The insertion value of the slot into which the TPC signal for changing the transmission output of the test target terminal cannot be switched based on the analysis result of the signal transmitted from the test target terminal.

  The present invention solves the above-mentioned problems, and can easily cope with various insertion patterns of signals for each physical channel constituting a frame with a small memory capacity configuration, and a signal to be inserted into a specific physical channel during signal transmission. It is an object of the present invention to provide a signal generation device and a signal generation method that can change the signal.

In order to achieve the above object, a signal generator according to claim 1 of the present invention comprises:
A transmission target signal format setting means (21) for setting format information of a transmission target signal in a first memory (22) among signals having a format in which a frame is constituted by a plurality of physical channels;
In accordance with the format information set in the first memory, a signal to be written in the second memory (24) by associating the baseband signal data to be inserted into the physical channel of each frame of the transmission target signal with the physical channel to be inserted Data writing means (23);
Based on the format information set in the first memory, the signal data written in the second memory is read in accordance with the transmission timing of the physical channel to be inserted, and the transmission target signal in the set format is output. And a signal data reading means (25) for generating a high frequency signal by orthogonally modulating the transmission target signal in the set format ,
By the transmission target signal format setting means, the physical channel number of the physical channels constituting one frame m, the number of samples _S2 1 ~S2 m insertable signal data for each physical channel, _i-th (i = 1 to m) When format information including k _i types of signal data that can be inserted into is set,
When the signal data writing means stores k _i types of signal data that can be inserted into the i-th physical channel in the second memory, the storage start address S1 _i for the physical channel , sample of the signal data, the number S2 _i, using the sample count value C of the remainder value Q1～Qk _i and the signal data of the frame number indicating the transmission order obtained by dividing the number of types k _i of the signal data of the frame, the k _i kind of signal data, respectively ,
S1 _i + S2 _i × Q1 + C
S1 _i + S2 _i × Q2 + C
......
S1 _i + S2 _i × Qk _i + C
Each of which is stored in the address area of the second memory indicated by
The signal data reading means counts the order of frames to be sent out by a counter (26), and a divider (27) outputs a signal for the jth (j = 1 to m) physical channel into which signal data is to be inserted. The count result is divided by the number of data types k _j to obtain the remainder value Q ′, and the read start address calculation means (29) inserts the storage head address S1 _j for the j-th physical channel and the physical channel. and sample number S2 _j of signal data, with the remainder value Q ', using said sample count C,
S1 _j + S2 _j × Q ′ + C
Are sequentially calculated, designated as a read address for the second memory, and signal data to be inserted into the jth physical channel is read .
A signal generator according to claim 2 of the present invention is the signal generator according to claim 1,
The signal data writing means, the second memory, and the signal data reading means are connected to the frequency in order to generate a signal for testing an LTE device that performs communication using a plurality of different frequency bands. A plurality of sets are provided according to the number of bands, and signal data for each frequency band is written to the second memory in an address area determined by the calculation using the remainder value, and the calculation using the remainder value is performed. Thus, signal data for each frequency band is read from each second memory in synchronization, and the transmission data for each read frequency band is added and synthesized and output.

A signal generator according to claim 3 of the present invention is the signal generator according to claim 1 or 2 ,
A switch (28) provided between the divider of the data reading means and the read address calculating means can specify a value in place of the remainder value to the read address calculating means .
Moreover, the test system according to claim 4 of the present invention comprises:
A signal generator according to claim 3;
A means for receiving a signal transmitted from the mobile terminal that has received the output signal of the signal generator and obtaining its strength;
In the signal generator, a plurality of signal data is set for a physical channel for transmission power control,
Instead of the remainder value, a numerical value that changes according to the intensity of the signal transmitted from the portable terminal is given to the read address calculation means via the switch and inserted into the transmission power control physical channel. The signal data is changed to change the transmission power of the mobile terminal.

The signal generation method according to claim 5 of the present invention includes:
Setting the format information of the transmission target signal in the first memory (22) among the signals having a format in which a frame is configured by a plurality of physical channels;
In accordance with the format information set in the first memory, writing baseband signal data to be inserted into the physical channel of each frame of the transmission target signal to the second memory (24) in association with the physical channel to be inserted When,
Based on the format information set in the first memory, the signal data written in the second memory is read in accordance with the transmission timing of the physical channel to be inserted, and the transmission target signal in the set format is output. and the step of,
A signal generation method comprising: orthogonally modulating a transmission target signal of the set format to generate and output a high-frequency signal ;
As the format information of the delivery target signal, the physical channel number of the physical channels constituting one frame m, the number of samples _S2 1 ~S2 m insertable signal data for each physical channel, _i-th (i = 1 to m) When format information including k _i types of signal data that can be inserted into is set,
The step of writing the signal data into the second memory includes storing a storage head address S1 _i for the physical channel when storing k _i types of signal data that can be inserted into the i-th physical channel in the second memory. , the number of samples S2 i of signal _data, by using the sample count value C of the remainder value Q1～Qk _i and the signal data of the frame number indicating the transmission order obtained by dividing the number of types k _i of the signal data of the frame, k _i type Each of the signal data
S1 _i + S2 _i × Q1 + C
S1 _i + S2 _i × Q2 + C
......
S1 _i + S2 _i × Qk _i + C
Each stored in the address area of the second memory indicated by
In the step of reading out the signal data, the order of the frames to be transmitted is counted, and the count result is expressed by the number of signal data types k _j for the jth (j = 1 to m) physical channel into which the signal data is to be inserted. The remainder value Q ′ is obtained by division, the storage start address S1 _j for the _jth physical channel, the number of signal data samples S2 _j to be inserted into the physical channel, the remainder value Q ′, and the sample count Using the number C,
S1 _j + S2 _j × Q ′ + C
Are sequentially calculated, designated as a read address for the second memory, and signal data to be inserted into the jth physical channel is read .

Thus, in the present invention, the number of physical channels m constituting one frame, the physical channel of each sample number of physical channels to be inserted signal data _S2 1 _~S2 m, i-th (i = 1 to m) When format information including k _i types of signal data that can be inserted is set, k _i types of signal data that can be inserted into the i th physical channel are stored in the second memory. using storage head address S1 _i, the number of samples S2 i of signal _data, the sample count value C of the remainder value Q1～Qk _i and signal data by dividing the frame number by the number of kinds k _i of the signal data indicating the transmission order of the frame , K _i types of signal data,
S1 _i + S2 _i × Q1 + C
S1 _i + S2 _i × Q2 + C
......
S1 _i + S2 _i × Qk _i + C
Is stored in the address area of the second memory indicated by (2), the order of frames to be transmitted is counted, and the signal data of the jth (j = 1 to m) physical channel into which the signal data is to be inserted is stored. The remainder result Q ′ is obtained by dividing the count result by the number of types k _j , the storage head address S1 _j for the _jth physical channel, the number S2 _{j of} signal data samples to be inserted into the physical channel, and the remainder value Using Q ′ and the sample count number C,
S1 _j + S2 _j × Q ′ + C
Are sequentially calculated, designated as a read address for the second memory, and signal data to be inserted into the jth physical channel is read.
For this reason, a signal to be inserted into a specific physical channel in real time without the complicated work of sequentially writing the read address of the signal data to be inserted into each physical channel for the entire transmission signal into the table as in the past. The data read address can be changed.

In addition, since the switch can specify a value in place of the above-described remainder value, in addition to the mode in which signal data to be inserted into the physical channel is sequentially switched depending on the frame number, for example, TPC bits cannot be predicted. The signal data of the specific physical channel can be changed at the timing, or the change of the signal data to be inserted into the specific physical channel can be regulated, and various test conditions can be handled.
Further, as in the test system of claim 4, the signal generator has means for receiving the signal transmitted from the portable terminal that has received the output signal of the signal generator and determining its strength, In the device, a plurality of signal data are set for the physical channel for transmission power control, and a numerical value that changes according to the intensity of the signal transmitted from the portable terminal is read via a switch instead of the remainder value. By giving to the address calculation means, it becomes possible to change the signal data inserted into the physical channel for transmission power control and change the transmission power of the portable terminal.

Configuration diagram of an embodiment of the present invention Signal format diagram for a system that communicates in multiple different frequency bands 2 is a diagram showing a part of the configuration corresponding to the signal format Diagram showing a simple example of signal format

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

  The signal generator 20 includes a transmission target signal format setting unit 21, a first memory 22, a signal data writing unit 23, a second memory 24, and a signal data reading unit 25.

  The transmission target signal format setting means 21 sets the format information of the transmission target signal desired by the user in the first memory 22 among signals having a format in which a frame is composed of a plurality of physical channels.

  The format information includes the number of transmission frames, the number of physical channels constituting the frame, the data amount of each physical channel, the channel in which the signal data to be inserted is unchanged (the constant channel), and the signal data are changed. It includes the type of channel (change channel), the change factor of signal data for the change channel, the type and order of signal data to be changed, and the like.

  Here, for easy understanding, as shown in FIG. 4 above, the signal is composed of three physical channels as one frame, and the signal data A is shared by using the first physical channel as an invariant channel among the physical channels. Three different types of signal data B1 to B3 are inserted in order using the second physical channel as a change channel, and two different types of signal data C1 and C2 are inserted alternately using the third physical channel as a change channel. Format information is set.

  In accordance with the format information set in the first memory 22, the signal data writing means 23 associates the signal data to be inserted into the physical channel of each frame of the transmission target signal with the physical channel to be inserted, respectively, in the second memory 24. Write to.

  As described above, this signal data writing means 23 is inserted into the specific physical channel when the format for changing the signal data to be inserted into the specific physical channel (second and third physical channels) in the frame is set. A plurality of types of scheduled signal data are stored in each address area of the second memory 24 calculated by a predetermined calculation using a predetermined change factor value as a variable.

  More specifically, assuming that the number of samples of the signal data A to be inserted into the first physical channel is S2a, the signal data A is stored in an area from address Ad1 to S2a in the second memory 24.

  If the number of samples of the signal data B1 to B3 to be inserted into the second physical channel is S2b, the signal data B1 is stored in the area from address Ad2 to S2b of the second memory 24, and the signal data B2 is It is stored in the subsequent area of S2b, and the signal data B3 is further stored in the subsequent area of S2b.

  If the number of samples of the signal data C1 and C2 to be inserted into the third physical channel is S2c, the signal data C1 is stored in the wide area from the address Ad3 to S2c of the second memory 24, and the signal data C2 is stored in it. It is stored in the subsequent area of S2c.

That is, in general terms, the storage head address corresponding to one physical channel is S1 (= Ad1, Ad2, Ad3), the number of sampled signal data is S2, the change factor value depending on the frame number is Index, When the count value of the sample is (Count), the write address of the signal data is expressed by the following arithmetic expression:
S1 + (S2) × (Index) + (Count)
Is calculated by

  Here, regarding the signal data A that does not change, it is only necessary to write one sample at an address that increases for each count value in the state of the change factor value 0.

  As for the signal data B1 to B3, it is only necessary to write one sample at an address that increases for each count value in the state of change factor values 0, 1, and 2, respectively.

  Further, with regard to the signal data C1 and C2, it is only necessary to write one sample at an address that increases for each count value in the state of the change factor values 0 and 1, respectively.

  Here, when the change factor is a frame number as in the above format example, the target signal data can be read by using the remainder value obtained by dividing the frame number by the number of types of signal data to be inserted as the change factor value. it can.

  The signal data reading means 25 switches the read addresses of a plurality of types of signal data stored in the second memory 24 by performing the calculation on the designated change factor value.

  Here, the signal data reading means 25 is a signal for inserting the counter 26 for counting the number of frames from the transmission start timing of the transmission target signal and the frame number Nf output from the counter 26 into the physical channel to be transmitted. A divider (remainder counter) 27 that divides by the number of data types and outputs the remainder value Q as a change factor value; a remainder value output by the divider 27; an input value V that changes at an arbitrary timing; and a fixed value Fix And a read address calculating means 29 for calculating a read address for the second memory 24 based on the arithmetic expression using the value selected by the switch 28 as a change factor value. . It is assumed that the signal data reading means 25 internally generates the switching timing of frames and physical channels and the insertion timing of signal samples for the physical channels according to the format information. It is assumed that the value selected by the switch 28 can be specified by the user.

  Here, if the switch 28 selects the remainder value Q, the signal data to be inserted into the first physical channel is one type of A, so the frame number Nf (initial value 0) is divided by the number of types 1. The remainder value (Index) at this time is 0, and from the above formula, the sample count value (Count) is calculated from the leading address Ad1 (= S1) of the signal data A at the transmission timing of the first physical channel in any frame. With the increase, reading of the sample value of the signal data A is started.

  Further, since there are three types of signal data B1 to B3 to be inserted into the second physical channel, the remainder value (Index) when the frame number Nf is divided by the number of types 3 is 0 → 1 → 2.

  Therefore, the remainder value Q (Index) of the transmission timing of the second physical channel is 0 in each frame of the frame number Nf = 0, 3, 6, 9,..., And the leading address of the signal data B1 that can be inserted into the second physical channel. Reading of the sample value of the signal data B1 is started as the sample count value Count increases from Ad2 (= S1).

  In each frame of frame number Nf = 1, 4, 7, 10..., The remainder value Q (Index) of the transmission timing of the second physical channel is 1, and the leading address of the signal data that can be inserted into the second physical channel Reading of the sample value of the signal data B2 is started from the address value obtained by adding the area S2 of the signal data B1 that has already been transmitted to Ad2 (S1) as the sample count value (Count) increases.

  Further, in each frame of frame number Nf = 2, 5, 8, 11,..., The remainder value Q (Index) of the transmission timing of the second physical channel is 2, and the leading address of the signal data that can be inserted into the second physical channel Reading of the sample value of the signal data B3 is started from the address value obtained by adding the area S2 × 2 of the signal data B1 and B2 already transmitted to Ad2 (S1) as the sample count value (Count) increases. Become.

  Further, since there are two types of signal data to be inserted into the third physical channel, C1 and C2, the remainder value Q (Index) when the frame number Nf is divided by the number of types 2 is 0 → 1.

  Therefore, the remainder value (Index) of the transmission timing of the third physical channel is 0 in each frame of the frame number Nf = 0, 2, 4, 6..., And the leading address Ad3 of the signal data C1 that can be inserted into the third physical channel. Reading of the sample value of the signal data C1 is started as the sample count value Count increases from (= S1).

  In each frame of the frame number Nf = 1, 3, 5, 7,..., The remainder value Q (Index) of the transmission timing of the third physical channel is 1, and the leading address of the signal data C1 that can be inserted into the third physical channel From the address value obtained by adding the area S2 of the signal data C1 that has already been transmitted to Ad3 (= S1), reading of the sample value of the signal data C2 is started as the sample count value Count increases.

  As described above, the signal data A to be inserted into the first physical channel is previously written in the area starting from the address Ad1 of the memory 24, and the three types of signal data B1 to B3 to be inserted into the second physical channel are written into the area starting from the address Ad2. By successively writing two types of signal data C1 and C2 to be inserted into the third physical channel into the area starting from the address Ad3, any one of the above formulas using the change factor value as a variable Compared to the method of inserting the signal into the physical channel of the frame in a pre-specified format and writing the address of the signal data stored in the memory at random to the sequence memory for the entire transmission signal and then reading it out, A signal of a desired format can be generated remarkably easily.

  In the above example, when multiple types of signal data are periodically switched and inserted for a specific physical channel in a frame, the remainder value obtained by dividing the frame number by the number of signal data types is used for signal type switching. However, if the input value V that changes at an arbitrary timing is selected instead of the remainder value Q as described above, the change factor value (Index) that switches when a certain condition is satisfied is selected. ) Can change the signal data of a specific physical channel to another. This is based on the reception strength when a transmission signal from a test target is received for a physical channel into which bit information of transmission power control (TPC) used as control in the case of an LTE or WCDMA portable terminal is inserted. It can be used as a mode for changing the change factor value and changing the signal inserted into the physical channel.

  Further, when a fixed value is selected as the change factor value (Index), even if there are a plurality of types of signal data to be inserted into each physical channel, the Index is fixed. Will be output repeatedly.

  In this way, not only a mode in which the type of signal data to be inserted into the physical channel is changed based on a change in the frame number, but also a mode in which the value changes when a predetermined condition is satisfied, The fixed mode that restricts the change of signal data type can be selected, which is convenient for the user.

  In the above description, a signal in which baseband signal data is inserted into a physical channel and a frame is formed is transmitted. However, signals actually handled are baseband I and Q signal data, and the above processing is performed. Is performed for two systems of I and Q. In a system that actually tests a portable terminal or the like, a high-frequency signal obtained by orthogonally modulating signals generated for the two systems I and Q in the above system is generated and given to a test object.

  Further, in the above example, the case where the signal sequence to be transmitted is one system (including I and Q) is shown. However, as shown in FIG. 2, communication is performed using a plurality of (three in the figure) frequency bands in combination. 1 is performed, the configuration of the embodiment shown in FIG. 1 is provided for the number of frequency bands (three sets) and operated in parallel so as to be synchronized in units of frames. 3, the signal data written in the second memories 24 </ b> A to 24 </ b> C of each frequency band is read according to the format information for each frequency band, and the transmission target signals Sout <b> 1 to Sout <b> 3 for each frequency band are added by the adder 30. (Addition of I components and Q components) may be performed, and the addition result Sout may be output.

  DESCRIPTION OF SYMBOLS 20 ... Signal generator, 21 ... Sending target signal format setting means, 22 ... First memory, 23 ... Signal data writing means, 24 ... Second memory, 25 ... Signal data reading means, 26 ... ... Counter, 27 ... Divider, 28 ... Switch, 29 ... Read address calculation means

Claims (5)

A transmission target signal format setting means (21) for setting format information of a transmission target signal in a first memory (22) among signals having a format in which a frame is constituted by a plurality of physical channels;
In accordance with the format information set in the first memory, a signal to be written in the second memory (24) by associating the baseband signal data to be inserted into the physical channel of each frame of the transmission target signal with the physical channel to be inserted Data writing means (23);
Based on the format information set in the first memory, the signal data written in the second memory is read in accordance with the transmission timing of the physical channel to be inserted, and the transmission target signal in the set format is output. And a signal data reading means (25) for generating a high frequency signal by orthogonally modulating the transmission target signal in the set format ,
By the transmission target signal format setting means, the physical channel number of the physical channels constituting one frame m, the number of samples _S2 1 ~S2 m insertable signal data for each physical channel, _i-th (i = 1 to m) When format information including k _i types of signal data that can be inserted into is set,
When the signal data writing means stores k _i types of signal data that can be inserted into the i-th physical channel in the second memory, the storage start address S1 _i for the physical channel , sample of the signal data, the number S2 _i, using the sample count value C of the remainder value Q1～Qk _i and the signal data of the frame number indicating the transmission order obtained by dividing the number of types k _i of the signal data of the frame, the k _i kind of signal data, respectively ,
S1 _i + S2 _i × Q1 + C
S1 _i + S2 _i × Q2 + C
......
S1 _i + S2 _i × Qk _i + C
Each of which is stored in the address area of the second memory indicated by
The signal data reading means counts the order of frames to be sent out by a counter (26), and a divider (27) outputs a signal for the jth (j = 1 to m) physical channel into which signal data is to be inserted. The count result is divided by the number of data types k _j to obtain the remainder value Q ′, and the read start address calculation means (29) inserts the storage head address S1 _j for the j-th physical channel and the physical channel. and sample number S2 _j of signal data, with the remainder value Q ', using said sample count C,
S1 _j + S2 _j × Q ′ + C
Are sequentially calculated, designated as a read address for the second memory, and signal data to be inserted into the jth physical channel is read . The signal data writing means, the second memory, and the signal data reading means are connected to the frequency in order to generate a signal for testing an LTE device that performs communication using a plurality of different frequency bands. A plurality of sets are provided according to the number of bands, and signal data for each frequency band is written to the second memory in an address area determined by the calculation using the remainder value, and the calculation using the remainder value is performed. The signal generator according to claim 1 , wherein the signal data for each frequency band is read from each second memory in synchronization with each other, and the transmission data for each read frequency band is added and synthesized and output . The switch (28) provided between said divider and said read address calculating means of said data reading means, wherein, characterized in that a value in place of the remainder value to be specified in the read address calculating means The signal generator of Claim 1 or Claim 2 . A signal generator according to claim 3;
A means for receiving a signal transmitted from the mobile terminal that has received the output signal of the signal generator and obtaining its strength;
In the signal generator, a plurality of signal data is set for a physical channel for transmission power control,
Instead of the remainder value, a numerical value that changes according to the intensity of the signal transmitted from the portable terminal is given to the read address calculation means via the switch and inserted into the transmission power control physical channel. A test system characterized by changing signal data and changing the transmission power of a portable terminal . Setting the format information of the transmission target signal in the first memory (22) among the signals having a format in which a frame is configured by a plurality of physical channels;
In accordance with the format information set in the first memory, writing baseband signal data to be inserted into the physical channel of each frame of the transmission target signal to the second memory (24) in association with the physical channel to be inserted When,
Based on the format information set in the first memory, the signal data written in the second memory is read in accordance with the transmission timing of the physical channel to be inserted, and the transmission target signal in the set format is output. And the stage of
A signal generation method comprising: orthogonally modulating a transmission target signal of the set format to generate and output a high-frequency signal;
As the format information of the transmission target signal, the number m of physical channels constituting one frame and the number S2 of signal data samples that can be inserted into each physical channel ₁ ~ S2 _m , K that can be inserted into the i th (i = 1 to m) physical channel _i When format information including the type of signal data is set,
The step of writing the signal data into the second memory includes inserting k into the i th physical channel. _i When storing the type of signal data in the second memory, the storage head address S1 for the physical channel _i , Number of samples of signal data S2 _i , The frame number indicating the frame transmission order is the number of signal data types k _i Remainder values Q1 to Qk divided by _i And the sample count value C of the signal data, k _i Each type of signal data
S1 _i + S2 _i × Q1 + C
S1 _i + S2 _i × Q2 + C
......
S1 _i + S2 _i × Qk _i + C
Each stored in the address area of the second memory indicated by
In the step of reading out the signal data, the order of the frames to be transmitted is counted, and the number k of types of signal data for the jth (j = 1 to m) physical channel into which the signal data is to be inserted. _j To divide the counting result to obtain the remainder value Q ', and the storage start address S1 for the jth physical channel _j And the number S2 of signal data samples to be inserted into the physical channel _j And the remainder value Q ′ and the sample count number C,
S1 _j + S2 _j × Q '+ C
The signal generation method is characterized in that the address indicated by is sequentially calculated, designated as a read address for the second memory, and signal data to be inserted into the jth physical channel is read.

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