JP2000286741A - Digital wireless microphone system - Google Patents

Abstract

(57) [Summary] PROBLEM TO BE SOLVED: To make the bit rate of a wireless microphone system variable according to the purpose, to incorporate a digital effector in a receiver, and to have expandability with a digital output terminal and a terminal for an external control device. To provide an excellent digital wireless microphone system with low system cost. A receiver receives a radio wave of a frequency emitted from a transmitter, performs digital demodulation, demodulates a compressed digital signal, decodes the signal, synthesizes a PCM digital signal, and generates a digital effector. Performs high-frequency amplification / frequency converter 9, intermediate frequency amplifier 10, demodulator 11, code conversion / deinterleave / error correction circuit 12, compression It comprises a signal decoder 13, a digital effector 16, a D / A converter 17, and an audio amplifier 18. In addition, an external control terminal 19 and a digital output terminal 20 are provided in consideration of expandability to the outside.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital wireless microphone system.

[0002]

2. Description of the Related Art Conventionally, a digital wireless microphone system disclosed in Japanese Patent Application Laid-Open No. H10-150692 is known.

FIG. 3 shows a configuration of a transmitter of a conventional digital wireless microphone system. The transmitter 1 includes an acoustic-electrical converter, an A / D converter 3, a compression encoder 4, a code converter
It comprises an interleave / error correction circuit 5, a modulation / amplification circuit 6, and a transmission antenna 7.

The receiver 2 includes a receiving antenna 8, a high-frequency amplifier / frequency converter 9, an intermediate frequency amplifier 10, a demodulator 11, a code conversion / deinterleave / error correction circuit 12, and an expansion decoder 13, which are sequentially connected. Have been.

Next, the operation of the transmitter 1 and the receiver 2 will be described. An acoustic signal such as a human voice is collected by a microphone and converted into electricity. At this time, the signal is amplified by an amplifier or the like. The analog electric signal is converted from an analog signal into a PCM digital signal by the AD converter 3,
The compression encoder 4 converts the bit stream into a low-rate bit string. This bit string is converted into a code string having resistance to a transmission path error by a code conversion / interleave / error correction circuit 5, converted into antenna power by a modulation / amplification circuit 6, and a radio wave is emitted from a transmission antenna 7. Is done.

[0006] The radio waves emitted from the transmitter 1 are input to the receiver 2 and output as audio signals from the receiver 2. First, the radio wave input to the receiving antenna 8 is
After being amplified by the frequency converter 9 and converted to the intermediate frequency, the intermediate frequency is amplified by the intermediate frequency amplifier 10 and the demodulator 11
Demodulates the digital signal. This digital signal is corrected for a transmission path error by a code conversion / deinterleave / error correction circuit 12, and a PCM digital signal is synthesized by an expansion decoder 13.

[0007]

However, in the above-mentioned conventional digital wireless microphone system, since the bit rate is fixed, the frequency use efficiency is improved,
The problem of not being able to cope with attempts to increase the number of channels, and the problem of howling, which requires a connection to an external effector such as a digital howling suppressor, increases the cost of the system. Had.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems, in which the bit rate of a wireless microphone system can be varied according to the purpose, and a digital effector is built in a receiver. It is an object of the present invention to provide an excellent digital wireless microphone system which has expandability by a device terminal and has a reduced system cost.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problem, the present invention provides a method for increasing the number of channels by changing the bit rates of a transmitter and a receiver according to the intended use and improving the frequency use efficiency. To respond. Further, the present invention provides a wireless microphone system in which a digital effector such as a howling suppressor is incorporated in a receiver of the digital wireless microphone system and has an external control terminal and a digital output terminal.

As described above, it is possible to obtain a low-cost digital wireless microphone system which can cope with the increase in the number of channels and does not require an external effector, and which can be extended to external devices.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION
This is a digital wireless microphone system characterized in that the bit rate of the transmitter and the receiver can be changed according to the intended use, and the bit rate of the system can be selected according to the purpose of use, improving the frequency efficiency. Therefore, it is possible to cope with multi-channel operation.

According to a second aspect of the present invention, in the digital wireless microphone system receiver according to the first aspect, a digital effector is built in, and a digital effector is connected to the outside. This has the effect that a digital wireless microphone system can be constructed at low cost without performing.

According to a third aspect of the present invention, there is provided a digital wireless microphone system according to the first aspect, further comprising a howling suppressor using a digital filter. It has the effect of detecting and suppressing howling.

According to a fourth aspect of the present invention, there is provided the digital wireless microphone system according to the first aspect, wherein the digital wireless microphone system includes an equalizer using a digital filter. This has the effect that the timbre can be changed without connection.

According to a fifth aspect of the present invention, in the digital wireless microphone system receiver according to the first aspect, there is provided a digital wireless microphone system having a volume variable circuit using a multiplier. There is an effect that the volume can be changed by digital signal processing without passing through.

According to a sixth aspect of the present invention, there is provided a digital wireless microphone system according to the first aspect, wherein the receiver has a sampling converter. It has an effect that a digital signal can be supplied.

According to a seventh aspect of the present invention, there is provided the digital wireless microphone system according to the first aspect, wherein the digital wireless microphone system has a digital reverb. This has the effect that a reverberant audio signal can be supplied without the need.

According to an eighth aspect of the present invention, there is provided the digital wireless microphone system according to the first aspect, wherein the digital wireless microphone system has a digital delay. It is possible to supply a delayed or echoed audio signal without any delay.

According to a ninth aspect of the present invention, there is provided a digital wireless microphone system according to the first aspect, wherein the digital wireless microphone system has a control terminal for enabling control from an external device. Yes, it has the effect of enabling operation of the receiver from an external device such as a personal computer, and enabling the external device to monitor the state of the receiver.

The invention according to claim 10 is the first invention.
The digital wireless microphone system described above has a digital output terminal of AES-EBU and S-PDIF, and can interface with other digital devices. Having.

An embodiment of the digital wireless microphone system according to the present invention will be described below with reference to FIGS.

FIG. 1 shows a configuration diagram of a digital wireless microphone system. In FIG. 1, a transmitter 1 collects sound, converts it into a PCM digital signal, performs compression encoding processing, and converts the compressed digital signal. A microphone 14, an audio amplifier 15, an A / D converter 3, a compression encoder 4, a code conversion / interleave / error correction circuit 5, a modulation amplification circuit 6 , And a transmission antenna 7.

The receiver 2 receives the radio wave of the frequency emitted from the transmitter 1, performs digital demodulation, demodulates the compressed digital signal, decodes the signal, synthesizes the PCM digital signal, and It performs an effect process by an effector and performs an operation of outputting an analog audio signal and a digital signal, and includes a high-frequency amplifier / frequency converter 9, an intermediate frequency amplifier 10, a demodulator 11, a code conversion / deinterleave / error correction circuit 12, Compressed signal decoder 13, digital effector 16, D / A converter 17, audio amplifier 18
It is composed of In addition, an external control terminal 19 and a digital output terminal 20 are provided in consideration of expandability to the outside.

The operation of the digital wireless microphone system configured as described above will be described with reference to FIGS.

First, an acoustic signal such as a sound input to the transmitter 1 is collected by a microphone 14 and amplified by an audio amplifier 15 to a certain level. The amplified analog audio signal is converted by the AD converter 3 into a PCM digital signal. The PCM digital signal is converted by the compression encoder 4 into a low-rate compressed signal. The bit rate is variable.

Next, the compressed signal is rearranged by a code conversion / interleaving and error correction circuit 5 into a bit configuration that is resistant to transmission path errors. The method is B as an example.
CH coding system and the like. The rearranged bit sequence is digitally modulated by the modulation and amplification circuit 6 and amplified. As a modulation method, a π / 4-DQPSK method is given as an example. The amplified signal is emitted through the transmitting antenna 7 into the air as radio waves.

Next, the operation of the receiver 2 will be described. First, the signal is input to a radio wave receiving antenna 8 emitted from the transmitter 1, amplified and frequency converted by a high frequency amplifier / frequency converter 9, amplified to an appropriate level by an intermediate frequency amplifier 10, and then modulated by a demodulator 11. Demodulate the previous signal. The demodulated signal is used for code conversion, deinterleaving, and error correction.
The transmission path error is corrected at 12 and the original P
Restore the CM digital signal. Here, the compressed signal decoder is of a variable rate type.

The restored PCM digital signal is subjected to predetermined processing by the digital effector 16. Examples of the processing include a howling suppressor processing using a digital filter, an equalizer processing using a digital filter, and a variable volume processing using a multiplier.

The processed PCM digital signal is distributed to a D / A converter 17 and a digital output terminal 20. The digital output conforms to the AES-EBU and S-PDIF standards, and can exchange digital signals with external digital devices. As an example, Figure 2 shows a digital mixer
The state of connection with 21 is shown. The connection with the digital mixer 21 can be exchanged with a digital signal via a cable 22a.

Since a digital effector for performing the above-described processing is built in, effect processing can be performed without connecting other peripheral effectors.

Further, by connecting the personal computer 23 and the like to the external control terminal 19, the parameters of the receiver can be operated, and the receiving state and the like can be monitored by the personal computer 23.

As described above, according to the embodiment of the present invention, it is possible to make the bit rate variable so as to cope with multi-channel operation, and by incorporating an effector, almost no external effector connection is required. It is possible to easily construct a digital wireless system that realizes wide scalability and low cost with an external control terminal by a personal computer or the like.

[0033]

As described above, according to the present invention, by making the bit rate of the wireless microphone system variable, it is possible to improve the frequency use efficiency and to cope with the increase in the number of channels. . Further, by providing the effector device and the external digital output terminal in the receiver of the digital wireless microphone system, it is possible to obtain a low-cost and highly expandable full digital wireless microphone system.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a digital wireless microphone system according to an embodiment of the present invention.

FIG. 2 is a diagram showing an example of a loudspeaker system constructed using a digital wireless microphone system according to the embodiment of the present invention;

FIG. 3 is a block diagram showing a configuration of a conventional digital wireless microphone system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transmitter 2 Receiver 3 A / D converter 4 Compression encoder 5 Code conversion / interleave / error correction circuit 6 Modulation / amplification circuit 7 Transmission antenna 8 Receiving antenna 9 High frequency amplification / frequency converter 10 Intermediate frequency amplifier 11 Demodulation 12 Code conversion / deinterleaving / error correction circuit 13 Compressed signal decoder 14 Microphone 15 Audio amplifier 16 Digital effector 17 DA converter 18 Audio amplifier 19 External control terminal 20 Digital output terminal 21 Digital mixer 22a to 22c Cable 23 PC 24 Speaker 25 High power amplifier

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme court ゛ (Reference) H04R 1/04 G10K 15/00 B 5K012 3/04 G10L 9/18 A 5K060 (72) Inventor Shinichi Ohko Matsushita Communication Industrial Co., Ltd. F term (reference) 5D017 BD04 BD09 5D020 AC06 CE03 5D045 DA20 5D108 AA07 AB07 5K011 DA03 DA12 DA13 DA15 DA28 JA01 KA06 5K012 AB05 AB18 AC01 AC08 AC10 AD03 BA02 5K060 AA11 BB04 DD07 KK06

Claims (10)

[Claims] 1. A digital wireless microphone system wherein a bit rate of a transmitter and a bit rate of a receiver can be changed according to an intended use. 2. A digital wireless microphone system according to claim 1, wherein a digital effector is built-in. 3. The digital wireless microphone system according to claim 2, wherein the digital effector of the digital wireless microphone system receiver includes a howling suppressor using a digital filter. 4. The digital wireless microphone system according to claim 2, wherein the digital effector of the digital wireless microphone system receiver includes an equalizer using a digital filter. 5. The digital wireless microphone system according to claim 2, wherein the digital effector of the digital wireless microphone system receiver includes a volume variable circuit using a multiplier. 6. The digital wireless microphone system according to claim 2, wherein the digital effector of the digital wireless microphone system receiver includes a sampling converter. 7. The digital wireless microphone system according to claim 2, wherein the digital effector of the digital wireless microphone system receiver includes a digital reverb. 8. The digital wireless microphone system according to claim 2, wherein the digital effector of the digital wireless microphone system receiver includes a digital delay. 9. The digital wireless microphone system according to claim 2, further comprising a control terminal controllable from an external device. 10. The receiver of the digital wireless microphone system according to claim 2, wherein AES-EBU, S-
A digital wireless microphone system having a PDIF standard digital output terminal.