JP2003229789A - Radio data transmitter and radio data receiver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radio data transmitter and receiver which can prevent burst data errors caused by switching of radio modulation frequency. <P>SOLUTION: In the radio data transmitter and receiver for performing radio transmission using frequency hopping method, the radio data transmitter divides input transmission data into a plurality of data slots, includes the same data slots in a plurality of frames, and transmits the plurality of frames at transmission timings different from the frequency switching interval in the frequency hopping scheme. A radio data receiver extracts the same data slots from a plurality of received frames, compares the received states of the plurality of same data slots, selects one of the plurality of identical data slots having the best received state, and outputs the selected data slot as received data. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless data transmitting apparatus and a wireless data receiving apparatus that perform wireless transmission using a frequency hopping method, and more particularly to a burst data error caused by switching of a wireless modulation frequency in the frequency hopping method. The present invention relates to a wireless data transmitting device and a wireless data receiving device for preventing the same.

[0002]

2. Description of the Related Art In recent years, wireless data transmitters and wireless data receivers that perform wireless transmission using a frequency hopping system have become widespread. The frequency hopping method is to perform radio transmission by switching the radio modulation frequency by a frequency synthesizer at a period sufficiently longer than the symbol period.

On the other hand, in the case of performing digital modulation / demodulation in the wireless data transmitting apparatus and the wireless data receiving apparatus, the wireless data transmitting apparatus divides the input transmission data into a certain length and performs frame generation for data transmission. To do. Usually, a UW (unique word) known by the wireless data transmitting device and the wireless data receiving device is added to the head of the frame generated by the wireless data transmitting device, and the wireless data receiving device uses the UW to perform synchronization processing and Performs waveform equalization processing.

Here, a conventional wireless data transmitting apparatus and wireless data receiving apparatus that perform wireless transmission using the frequency hopping method will be described with reference to FIG. First, a conventional wireless data transmission device will be described with reference to FIG. As shown in FIG. 4A, this wireless data transmission device includes a transmission frame generation unit 11, a UW addition unit 12, a modulation signal generation unit 13, a quadrature modulation unit 14, a transmission high frequency unit 15, and a transmission unit. The antenna 16 is used.

First, the transmission data is transmitted frame generation unit 1
Input to 1. The transmission frame generation unit 11 generates transmission frame data having a fixed data length using the transmission data, adds the UW stored in the UW addition unit 12 to the beginning of each transmission frame data, and generates a transmission frame. ,
It outputs to the modulation signal generation unit 13. FIG. 5 is a diagram showing an example of the configuration of a transmission frame generated by the conventional wireless data transmission device. As shown in FIG. 5, the transmission data is divided into transmission frame data (data 1, data 2, ...) Having a fixed data length, and each transmission frame data with UW added at the beginning is transmitted. It becomes a frame (frame 1, frame 2, ...).

[0006] The modulated signal generator 13 performs modulation processing such as QAM (Quadrature Amplitude Modulation) on the transmission frame and outputs it to the orthogonal modulator 14 as a transmission baseband signal having an I-phase component and a Q-phase component. The quadrature modulator 14 performs quadrature modulation by multiplying a transmission baseband signal by a local frequency and adding each signal component, and the result is transmitted by an IF (Intermediate Freq.
quency) signal to the transmission high frequency unit 15. The transmission high frequency unit 15 uses a frequency synthesizer that generates a radio modulation frequency to transmit RF (Radio Fr) from the transmission IF signal.
frequency hopping is performed by converting the frequency of the radio modulation frequency into a signal that is sufficiently longer than the symbol period. The transmission RF signal is transmitted to the radio space via the transmission antenna 16.

Next, a conventional radio data receiving apparatus will be described with reference to FIG. As shown in FIG. 4B, this wireless data receiving device includes a receiving antenna 21 and
Reception high frequency section 22, quadrature detection section 23, and synchronization processing section 2
4, an equalization processing unit 25, and a data demodulation unit 26.

First, the received RF which is frequency hopping
The signal is received by the receiving antenna 21 and is received by the receiving high frequency unit 2.
In 2 the frequency is converted to the received IF signal and output to the quadrature detection unit 23. The quadrature detection unit 23 performs quadrature detection by multiplying the received IF signal by a local frequency, and outputs the result to the synchronization processing unit 24 as a reception baseband signal having an I-phase component and a Q-phase component. Synchronization processing unit 24
Performs a complex correlation operation between the UW included in the received baseband signal and the UW that the wireless data receiving device has in advance, detects the synchronization point of the received baseband signal, and equalizes the received frame obtained as a result. Output to 25. The equalization processing unit 25 compensates the distortion received on the transmission line by the waveform equalization processing of the received frame and outputs it to the data demodulation unit 26. The data demodulation unit 26 performs data demodulation processing such as QAM demapping processing on the output of the equalization processing unit 25, and outputs the received data obtained as a result to the outside.

[0009]

However, when the above-mentioned wireless data transmission device performs wireless transmission using the frequency hopping method, it takes several ms to switch the wireless modulation frequency by the frequency synthesizer. FIG. 6 is a diagram showing an example of a received RF signal and a received frame in a conventional wireless data receiving device. As shown in FIG. 6, a non-signal section for several ms occurs in the received RF signal due to switching of the radio modulation frequency, and received frame data (data 2, data 4, data 6, Data 7) is missing. As a result, it is inevitable that a burst data error will occur in the received data.
Conventionally, burst-like data errors caused by switching the radio modulation frequency have been mitigated by using error correction codes, etc. It is very difficult to secure communication quality.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a radio data transmitting apparatus and a radio data receiving apparatus which prevent burst data errors caused by switching of radio modulation frequencies. .

[0011]

In order to achieve the above-mentioned object, the present invention, in a wireless data transmitter for performing wireless transmission using a frequency hopping system, divides input transmission data into a plurality of data slots. However, in the wireless data transmission device that transmits the same data slot by including it in a plurality of frames with different transmission timings, the transmission interval of the plurality of frames does not match the frequency switching interval in the frequency hopping method. It is characterized by that.

According to this structure, since any one of the same received data slots received by the wireless data receiving device is not affected by the frequency switching, burst data error can be prevented. You can

The present invention is also a wireless data receiving device for receiving a frame transmitted by the above-mentioned wireless data transmitting device, wherein the same data slot is extracted from the plurality of received frames, and a plurality of the same data is extracted. The reception states of the slots are compared, a predetermined data slot is selected based on the comparison result, and the selected data slot is output as reception data.

With such a configuration, for example, the reception data slot having the best reception state can be obtained as reception data from the same reception data slot received by the radio data receiving device, and the communication quality is improved.

Further, according to the present invention, in the radio data receiving apparatus according to claim 2, waveform equalization processing is performed on the plurality of received same data slots, and an error as a result of the waveform equalization processing is calculated, The power sum of the errors for each data slot is set to the reception state, and the data slot with the smallest power sum is selected from the plurality of the same data slots as the predetermined data slot.

With such a configuration, the reception data slot having the best reception state can be obtained as reception data from the same reception data slot received by the radio data receiving device.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing an example of a configuration of a wireless data transmission device and a wireless data reception device according to the present invention. The wireless data transmitting device and the wireless data receiving device according to the present embodiment perform wireless transmission using the frequency hopping method.

First, a wireless data transmission apparatus according to the present invention will be described with reference to FIG. As shown in FIG. 1 (a), this wireless data transmission device has a transmission data slot generation unit instead of the transmission frame generation unit 11 and the UW addition unit 12 in the conventional wireless data transmission device shown in FIG. 4 (a). 101, a transmission data slot storage memory 102, a UW memory 103, and a transmission frame generation unit 104. In FIG. 1A, the same symbols as those in FIG.
Shows the same as or equivalent to the object shown in (a),
The description here is omitted.

The operations of the transmission data slot generation unit 101, the transmission data slot storage memory 102, the UW memory 103 and the transmission frame generation unit 104 in the radio data transmission apparatus according to the present invention will be described below. First, the transmission data is input to the transmission data slot generation unit 101. The transmission data slot generator 101 slots the transmission data into a data length shorter than one transmission frame data length to generate transmission data slots, and stores the transmission data slots in the respective transmission data slot storage memories 102. Each of the plurality of transmission data slot storage memories 102 adds the UW stored in the UW memory 103 to the head of the stored transmission data slot, and outputs the UW stored in the transmission frame generation unit 104. The transmission frame generation unit 104 generates a transmission frame by allocating a plurality of transmission data slots with UW added to the frame.

Here, the structure of the transmission frame generated by the transmission frame generation unit 104 will be described with reference to FIG. Hereinafter, a case where one transmission frame has two transmission data slots will be described. First, the transmission data slots (S1, S2, S3, ...) Generated by the transmission data slot generation unit 101 are stored in the respective transmission data slot storage memories 102. The transmission frame generation unit 104 replaces the first transmission data slot S1 with
It is assigned to the second data slot of the transmission frame F1 at the transmission frame timing T. Transmission frame generation unit 104
Indicates the second transmission frame (F2, F3, ...) Of each transmission frame timing (T + 1, T + 2, ...) In sequence after the second transmission data slot S2.
Assign to data slot.

Further, the transmission data slot S1 is reallocated to the first data slot of the transmission frame at the transmission timing after a certain delay time has elapsed from the transmission timing T. Here, the number of delay frames is set to 3, and the transmission data slot S1 is reassigned to the transmission frame F4 at the transmission timing T + 3. It is necessary to set the number of delay frames when reallocating the same transmission data slot, that is, the transmission timing, so as to be different from the radio modulation frequency switching interval.

The transmission frames (F1, F2, F3, ...) Generated by the transmission frame generation unit 104 are the same as in the conventional radio data transmission apparatus, the modulation signal generation unit 13, the quadrature modulation unit 14, and the transmission high frequency unit. It is transmitted to the wireless space via 15 and the transmitting antenna 16.

Next, the radio data receiving apparatus according to the present invention will be described with reference to FIG. As shown in FIG. 1 (b), this wireless data transmitting apparatus has a reception data slot generating section 201 and a first data instead of the equalization processing section 25 in the conventional wireless data receiving apparatus shown in FIG. 4 (b). Slot equalization processing unit 202a, first data slot storage memory 203a, and second data slot equalization processing unit 202
b, the second data slot storage memory 203b, the slot equalization error comparison unit 204, and the reception data slot selection unit 20.
5 is provided. In FIG. 1 (b), the same reference numerals as those in FIG. 4 (b) indicate the same or corresponding objects as those shown in FIG. 4 (b), and description thereof will be omitted here.

Hereinafter, the reception data slot generation unit 201, the first data slot equalization processing unit 202a, the first data slot storage memory 203a, and the second data slot equalization processing unit 202b in the radio data receiving apparatus according to the present invention will be described.
A second data slot storage memory 203b, a slot equalization error comparison unit 204, and a received data slot selection unit 205.
The operation of will be described. First, the reception frame output from the synchronization processing unit 24 is the reception data slot generation unit 20.
Input to 1. The reception data slot generation unit 201
A plurality of received data slots that form a received frame are extracted. As described above, since the received data slots that make up one received frame are two, that is, the first data slot and the second data slot, the received data slot generation unit 201 has two received data slots for each received frame. The slots are extracted, and the first data slot equalization processing unit 202a and the second data slot equalization processing unit 20 are extracted.
Output to 2b.

First data slot equalization processing unit 202a
Performs the waveform equalization process on the first data slot, calculates the equalization error power sum, and stores the result of the waveform equalization process and the equalization error power sum in the first data slot storage memory 203a. Here, the sum of equalization error powers means that the result of waveform equalization processing is performed by arranging received symbols consisting of an I-phase component and a Q-phase component in a signal space such as QAM, and calculating the power of an error with respect to the originally intended symbol position. Is obtained and summed over a fixed number of received symbols. Similarly, the second data slot equalization processing unit 202b performs waveform equalization processing of the second data slot, calculates the equalization error power sum, and outputs the waveform equalization processing result and the equalization error power sum to the second.
The data is stored in the data slot storage memory 203b. The equalization error power sum of each reception data slot calculated here is set as the reception state of each reception data slot, and the reception data slot selection unit 205 uses the equalization error power sum as a reference for selecting the reception data slot. To do.

The first data slot storage memory 203a and the second data slot storage memory 203b need to store as many reception data slots as the number of delay frames when the same transmission data slot is transmitted by the wireless data transmitter. As described above, since the number of delay frames when transmitting the same transmission data slot is 3 here, the first data slot storage memory 203a and the second data slot storage memory 203b store the past 3 frames from the latest frame. The receive data slot assigned to the frame is stored.

The slot equalization error comparison unit 204 compares the equalization error power sums of the same received data slots stored in the first data slot storage memory 203a and the second data slot storage memory 203b, respectively, The comparison result is output to reception data slot selecting section 205.
The reception data slot selection unit 205 determines the reception data slot having the smaller sum of equalization error powers as the first reception data slot according to the comparison result.
The data slot storage memory 203a or the second data slot storage memory 203b is selected.

FIG. 3 is a diagram showing a received RF signal and a received frame in the wireless data receiving apparatus according to the present invention, and a selected received data slot. As shown in FIG. 3, a non-signal section occurs in the received RF signal due to switching of the radio modulation frequency, and the reception data slot S2 included in the second reception frame F2 and the reception included in the fourth reception frame F4 overlapping the non-signal section. The data slot S1 and the reception data slot S3 included in the sixth reception frame F6 are missing. On the other hand, another received data slot having the same contents as these received data slots but different reception timing is not missing. For example, the reception data slot S1 of the first reception frame F1 is not missing. This is because, in the wireless data transmission device, the same transmission data slot is assigned to two transmission frames provided with a transmission timing interval different from the radio modulation frequency switching interval.

The reception data slot selection unit 205 uses the first reception data slot that is the same reception data slot and has no missing data.
Of the reception data slot S1 of the reception frame F1 and the reception data slot S1 of the fourth reception frame F4 in which the reception data is missing, the equalization error power sum is calculated according to the comparison result output from the slot equalization error comparison unit 204. The smaller received data slot, that is, the received data slot S1 of the more reliable first received frame F1 is selected. Similarly, the reception data slot selection unit 205 receives the reception data slot S3 of the third reception frame F3, which is the same reception data slot with no reception data loss, and the reception data slot S3 of the sixth reception frame F6 with reception data loss. Among them, according to the comparison result output from the slot equalization error comparison unit 204, the reception data slot with the smaller equalization error power sum, that is, the reception data slot S3 of the more reliable third reception third frame F3 is selected. select.

Finally, the data demodulation section 26 performs data demodulation processing such as QAM demapping processing on the selected reception data slot and outputs the reception data to the outside.

In this embodiment, Q is used as the modulation method.
Although AM is used, other modulation methods such as the PSK modulation method may be used. Further, in the present embodiment, the equalization error power sum is used as the reference for selecting the reception data slot, but an error detection result may be used instead of the equalization error power sum. Specifically, an error detection code is added to the transmission data slot in the wireless data transmission device, the error detection result of the same reception data slot calculated in the wireless data reception device is used as a reference for selecting the reception data slot, You may make it select the reception data slot with few errors.

[0032]

As described in detail above, according to the present invention,
It is possible to reduce the burst data error caused by the switching of the radio modulation frequency in the frequency hopping system and to provide the improvement of the communication quality.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of a configuration of a wireless data transmitter and a wireless data receiver according to the present invention.

FIG. 2 is a diagram showing an example of a configuration of a transmission frame generated by the wireless data transmission device according to the present invention.

FIG. 3 is a diagram showing a received RF signal and a received frame in a wireless data receiving device according to the present invention, and a selected received data slot.

FIG. 4 is a block diagram showing an example of a configuration of a conventional wireless data transmitter and wireless data receiver.

FIG. 5 is a diagram showing an example of a configuration of a transmission frame generated by a conventional wireless data transmission device.

FIG. 6 is a diagram showing a received RF signal and a received frame in a conventional wireless data receiving device.

[Explanation of symbols]

101 transmission data slot generation unit, 102 transmission data slot storage memory, 103 UW memory, 104
Transmission frame generation unit, 13 modulated signal generation unit, 14 quadrature modulation unit, 15 transmission high frequency unit, 16 transmission antenna,
21 reception antenna, 22 reception high frequency part, 23 orthogonal detection part, 24 synchronization processing part, 201 reception data slot generation part, 202a first data slot equalization processing part,
202b second data slot equalization processing unit, 203a first data slot storage memory, 203b second data slot storage memory, 204 slot equalization error comparison unit,
205 reception data slot selection unit, 26 data demodulation unit.

Claims (3)

[Claims] 1. A wireless data transmitter for wirelessly transmitting by using a frequency hopping method, wherein input transmission data is divided into a plurality of data slots, and the same data slot is included in a plurality of frames having different transmission timings for transmission. The wireless data transmitting apparatus according to claim 1, wherein the transmission intervals of the plurality of frames are set not to match the frequency switching interval in the frequency hopping method. 2. A wireless data receiving device for receiving a frame transmitted by the wireless data transmitting device according to claim 1, wherein the same data slot is extracted from the plurality of received frames, and a plurality of the same data is extracted. A radio data receiving apparatus, characterized in that the reception states of slots are compared, a predetermined data slot is selected based on the comparison result, and the selected data slot is output as reception data. 3. The wireless data receiving apparatus according to claim 2, wherein waveform equalization processing is performed on the plurality of received same data slots, and an error of a result of the waveform equalization processing is calculated,
A radio data receiving apparatus, wherein the power sum of the errors for each data slot is set to the reception state, and the data slot having the smallest power sum is selected from the plurality of the same data slots as the predetermined data slot.