KR100270660B1 - Terminal and Voice Channel Switching Method in Wireless Subscriber Network System - Google Patents

Abstract

A terminal and a voice channel switching method of a wireless subscriber network system are disclosed. The present invention provides a wireless subscriber network system for wirelessly connecting subscriber lines between a base station and a subscriber device in a fixed network, and converts voice received from the voice subscriber device into a first PCM signal or a second PCM signal from a data subscriber device. Digital signal processing processor for compressing the first PCM signal into a compressed signal by the ADPCM or LD-CELP method, a control processor for generating a control signal for communication between the terminal and the base station, the first PCM signal Switching unit for multiplexing the second PCM signal and the compressed signal from the digital signal processor and the control signal from the control processor, and a modem for modulating the multiplexed signal into I and Q signals. A combiner for combining the modulated I and Q signals and the combined signal to a radio frequency The ring includes a high frequency to be transmitted through the transmission antennas. The terminal can reduce the unit cost and volume of the terminal by using a digital signal processor for voice compression, and can also expand the capacity of the wireless voice channel by using LD-CELP instead of the ADPCM. By switching to, the call path can be used efficiently.

Description

Terminal and Voice Channel Switching Method in Wireless Subscriber Network System

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless local loop (WLL) system. In particular, a terminal consisting of a fixed station and a wireline telephone uses a variety of voice compression techniques to switch a voice channel. The present invention relates to a terminal and a voice channel switching method.

A wireless subscriber network system using wideband Code Division Multiple Access (CDMA) technology wirelessly connects a landline subscriber terminal to a telephone station. The wireless subscriber network system is basically the same as the mobile communication system except that the subscriber terminal is fixed and therefore not mobile. This system is capable of voice, fax, internet, packet data service, etc., and saves installation cost and time.

1 is a block diagram of a wireless subscriber network according to the prior art. This prior art is disclosed in US Pat. No. 5,603,095 "RADIO SYSTEM AND A SUBSCRIBER TERMINAL FOR A RADIO SYSTEM." As shown in the figure, a system structure that can be applied to all kinds of wireless systems using a wireless subscriber network to replace a subscriber line between a fixed network and a subscriber is shown.

The wireless subscriber network system includes a fixed subscriber station (FSU) connected to the subscriber device 110, that is, a terminal 120, a radio carrier station (RCS) 130 wirelessly connected to the terminal, and a base station. Public Switched Telephone Network (RDU) 140 connected to a relay line, a Local Exchange (LE) 150 connected to a base station controller and a relay line, and a public switched telephone network connecting the switch to another network. PSTN) 160.

The prior art wireless subscriber network system uses a 32kbps Adaptive Differential PCM (ADPCM) scheme to compress the voice. Therefore, the terminal 120 of the wireless subscriber network system according to the related art uses an ADPCM processor configured of an ADPCM chip for converting PCM-modulated voice into ADPCM. The advanced wireless subscriber network system can support 16kbps Low Delay Code Excited Linear Prediction (LD-CELP).

Figure 2 shows the internal structure of the terminal 120 according to the prior art. The subscriber device 110 is divided into a voice subscriber device such as a landline telephone that generates an analog voice signal and a data subscriber device that generates digital data according to a service type. The voice generated by the voice subscriber device is compressed again in the 32kbps ADPCM method, but since the data generated by the data subscriber device is transmitted in 64kbps PCM, the subscriber unit 210 of the terminal 120 is transferred from the voice or data subscriber device. The PCM signal is transmitted or compressed as it is in PCM form.

The ADPCM processor 220 compresses the PCM signal transmitted through the PCM channel 1 into an ADPCM signal. However, the PCM signal transmitted through the PCM channel 2 is bypassed without going through the ADPCM processor. The main control unit 240 selects a call path to which a signal of the subscriber unit is to be transmitted according to the service type of the subscriber device. The modem unit 230 modulates the signal transmitted through the call path 1 or the call path 2 into an I (In phase) signal and a Q (Quadrature) signal. The high frequency part converts the modulated I and Q signals to radio frequency and then transmits them to the antenna.

Also, the high frequency unit converts the radio frequency signal received through the antenna into an intermediate frequency signal, and then transfers the intermediate frequency signal to the modem unit 230. The modem section demodulates the intermediate frequency signal. The demodulated signal transmitted to the communication path 3 passes through the ADPCM processing unit 220 and is restored to the ADPCM method. The demodulated signal transmitted to the channel 4 is bypassed. The signal transmitted through the call path 3 and the call path 4 is converted into an analog signal by the subscriber unit 210 and transmitted to the subscriber as a voice signal. The operations of the subscriber unit 210, the ADPCM processing unit 220, and the modem unit 230 are controlled by the main control unit 240.

In the terminal 120 according to the related art, the ADPCM processing unit 220 cannot support 16 kbps LD-CELP, which is an advanced speech compression method. That is, since the terminal of the wireless subscriber network according to the prior art uses the ADPCM processing unit composed of the ADPCM chip, the unit price and volume of the terminal are large, and 16 kbps LD-CELP voice compression cannot be performed. There was a problem.

The present invention has been made to solve the problems of the prior art operating as described above, Digital signal processing processor capable of compressing the signal converted to the PCM in the subscriber unit by 32kbps ADPCM or 16kbps LD-CELP method (Digital An object of the present invention is to provide a terminal and a voice channel switching method of a wireless subscriber network system using a signaling processor (DSP).

The present invention provides a terminal and a voice channel switching method of a wireless subscriber network system capable of multiplexing and transmitting a signal converted from a subscriber unit into a PCM and a signal compressed by a 32kbps ADPCM or 16kbps LD-CELP scheme. The purpose.

Other objects and advantages of the present invention will become more apparent from the following detailed description of the invention and the accompanying drawings.

1 is a block diagram of a wireless subscriber network according to the prior art.

2 is a diagram illustrating an internal structure of a terminal 120 according to the prior art.

3 is a block diagram of a terminal including a switching unit according to the present invention.

4 is a flowchart illustrating a voice channel switching method of a transmission switching unit according to the present invention.

<Description of the code | symbol about the principal part of drawing>

110: subscriber device 120: terminal

130: base station 140: base station controller

150: switchboard 160: public switched telephone network

210,310: Subscriber 220: ADPCM processing unit

230,350: modem portion 240: main control portion

1,2,3,4: Call path 320,390: Switching unit

330,380: digital signal processing processor 340: control processor

360: coupling part 365: distribution part

370: high frequency unit 410,420,430,440: selector

11, 12, 13, 21, 22, 23, 24, 25, 26, 27: signal

In order to achieve the above object, a preferred embodiment of a terminal of a wireless subscriber network system according to the present invention is a wireless subscriber network system for wirelessly connecting a subscriber line between a base station of a fixed network and a subscriber device.

A subscriber unit for converting a voice received from the voice subscriber device into a first PCM signal or receiving a second PCM signal from the data subscriber device;

A digital signal processing processor (DSP) for compressing the first PCM signal into a compressed signal by an ADPCM or LD-CELP scheme;

A control processor for generating a control signal for communication between the terminal and the base station;

A transmission switching unit configured to transfer the first PCM signal to a digital signal processing processor, and to multiplex the second PCM signal, a compressed signal transmitted from the digital signal processing processor, and a control signal transmitted from a control processor;

A modem unit for modulating the multiplexed signal into I and Q signals;

A combiner for combining the modulated I and Q signals;

It includes a high frequency unit for converting the combined signal into a radio frequency to transmit through a transmission antenna.

Another preferred embodiment of a terminal of a wireless subscriber network system according to the present invention is a wireless subscriber network system for wirelessly connecting a subscriber line between a base station of a fixed network and a subscriber device,

A high frequency unit receiving a radio frequency signal through a receiving antenna and converting the radio frequency signal into an intermediate frequency signal;

A divider for distributing the converted signal into I and Q signals;

A modem unit for demodulating I and Q signals;

A reception switching unit that separates the demodulated signal into a second PCM signal, a compressed signal, and a control signal;

A digital signal processor for restoring the compressed signal to a first PCM signal by an ADPCM or LD-CELP scheme;

A control processor for receiving and analyzing the control signal;

And a subscriber unit for transmitting the second PCM signal to a data subscriber device or converting the first PCM signal into voice and transmitting the voice signal to a voice subscriber device.

Another preferred embodiment of a terminal of a wireless subscriber network system according to the present invention is a wireless subscriber network system for wirelessly connecting a subscriber line between a base station of a fixed network and a subscriber device,

A subscriber unit for converting a voice signal transmitted from the subscriber device into a PCM signal by pulse code modulation (PCM);

A digital signal processing processor for compressing the PCM signal by an adaptive differential PCM (ADPCM) scheme or a low delay code excitation linear prediction (LD-CELP) scheme;

A modem unit for modulating the PCM signal and the compressed signal into an intermediate frequency signal;

A high frequency unit converting the intermediate frequency signal into a radio frequency signal and transmitting the radio frequency signal to an antenna;

And a control processor for controlling the modulation function of the modem unit.

Another preferred embodiment of a voice channel switching method of a wireless subscriber network system according to the present invention is a wireless subscriber network system for wirelessly connecting a subscriber line between a base station and a subscriber device of a fixed network. Connect the

Determining a service type of a subscriber device connected to the terminal;

If the subscriber device is a voice subscriber device generating a voice signal, the digital signal processing processor converts the first pulse code modulation (PCM) signal transmitted through the subscriber unit into an adaptive differential PCM (ADPCM) scheme or a low delay code excitation linear prediction (LD−). Compressing the signal into a compressed signal by a CELP) scheme;

If the subscriber device is a data subscriber device generating digital data, bypassing the second PCM signal transmitted through the subscriber unit; and

Transmitting the compressed signal and the second PCM signal.

In the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. Terms to be described later are terms defined in consideration of functions in the present invention, and may be changed according to intentions or customs of users or operators. Therefore, the definition should be made based on the contents throughout the specification.

Terminal 120 according to the present invention has a digital signal processing processor in place of the ADPCM processing unit to support both 32kbps ADPCM and 16kbps LD-CELP. The digital signal processor compresses the PCM signal by the 32kbps ADPCM method or the 16kbps LD-CELP method. The compression method may be set by an administrator.

The terminal must distinguish between the PCM signal received from the data subscriber device and the compressed signal received from the voice subscriber device. Therefore, the terminal according to the present invention time-division multiplexes 64kbps PCM signal, 32kbps ADPCM or 16kbps LD-CELP signal, and various control signals for communication between the terminal and the base station and simultaneously transmits them in one call, and demultiplexes the multiplexed signal. It further comprises a switching unit. The call in the terminal delivers a PCM signal, a compressed signal (ADPCM or LD-CELP), and a control signal. The switching unit is composed of a field programmable gate array (FPGA).

One call typically includes 32 time division multiplexing channels, or Time Slots. The first timeslot carries a 64kbps PCM signal, the second timeslot carries a 32kbps ADPCM or 16kbps LD-CELP signal, and the third timeslot carries a control signal. Do not use the remaining timeslots.

If a fixed station is connected with one voice subscriber device generating an analog signal and one data subscriber device generating digital data, only three timeslots are needed. However, if more subscriber devices are connected, more timeslots are needed. The present specification describes a method of switching a voice channel with a terminal connected to one voice subscriber device and one data subscriber device. However, the terminal and the method according to the present invention also apply to the case where the terminal is connected to two or more subscriber devices.

In order to load the compressed data by using different methods in the transmission path on one communication path and to distinguish the data received in one communication path in the reception path, the terminal according to the present invention transmits / outputs a voice channel. Use a receive switch. 3 is a block diagram of a terminal including a switching unit according to the present invention. Hereinafter, with reference to the accompanying drawings will be described in detail the operating principle of the preferred embodiment of the present invention.

The transmission path of the terminal according to the present invention includes a subscriber unit 310 for converting a voice received from a voice subscriber device such as a landline telephone into a first PCM signal or receiving a second PCM signal from a data subscriber device such as a fax machine; Digital signal processing processor 330 for compressing the first PCM signal received from the voice subscriber device into a compressed signal by the ADPCM or LD-CELP method, a control processor 340 for generating a control signal for communication, the subscriber unit The first PCM signal 11 transmitted from the digital signal processing processor and the second PCM signal 11 transmitted from the subscriber unit and the compressed signal 12 and control processor transferred from the digital signal processing processor. A transmission switching unit 320 for time division multiplexing the control signals 13, a modem unit 350 for modulating the multiplexed signals 21, 22 and 23 into I and Q signals of an intermediate frequency, and the modulated IAnd a combiner 360 for combining the Q signal and a high frequency unit 370 for converting the combined signal into a radio frequency and transmitting the converted signal to an antenna.

The terminal uses a digital signal processing processor 330 to perform voice compression by 32kbps ADPCM and 16kbps LD-CELP. As the digital signal processing processor is used, the terminal distinguishes the voice channel using the transmission switching unit 320. The transmission switching unit determines the service type of the subscriber device connected to the subscriber unit, and transfers or bypasses the PCM signal transmitted from the subscriber unit to the digital signal processing processor 330. 4 is a flowchart illustrating a voice channel switching method of a transmission switching unit according to the present invention.

If the terminal is connected to a voice subscriber device such as a landline telephone, the subscriber unit 310 converts the voice signal generated by the voice subscriber device into a first PCM signal. However, if the terminal is connected to a data subscriber device such as a fax, the data subscriber device generates a second PCM signal, so that the subscriber unit 310 transmits the second PCM signal generated at the data subscriber device to the transmission switching unit. In operation S110, the transmission switching unit 320 determines the service type of the subscriber device connected to the terminal. If the subscriber device is a voice subscriber device generating a voice signal, the transmission first selector 420 of the transmission switching unit 320 may control the first PCM signal transmitted through the subscriber unit under the control of the control processor. 330). In step S120, the digital signal processing processor compresses the first PCM signal into a signal compressed by the ADPCM method or the LD-CELP method. The digital signal processor passes the compressed signal 12 to the transmit second selector 420.

If the subscriber device is a data subscriber device for generating digital data, in step s130, the transmission first selector 410 of the transmission switching unit 320 transmits the second PCM signal transmitted through the subscriber unit under the control of the control processor. 11) bypasses the transmit second selector 420.

The transmitting second selector transmits the compressed signal 12 and the second PCM signal 11 to the modem unit 350. In this case, the transmitting second selector multiplexes the control signal 13 and the signals 11 and 12 generated by the control processor to different time slots, respectively, and transmits them to the modem unit 350. The transmitting second selector carries the second PCM signal 11 in a first time slot, the compressed signal 12 in a second time slot, and the control signal 13 in a third time slot. The modem unit 350 modulates the multiplexed signals 21, 22 and 23 into I and Q signals, the combiner 360 combines the I and Q signals, and the high frequency unit 370 combines the combined signals. Transmits to the base station via radio frequency.

In addition, the reception path of the terminal according to the present invention, a high frequency unit 370 for receiving a radio frequency signal through an antenna and converts it into an intermediate frequency signal, a divider 365 for distributing the converted signal into I and Q signals, distribution Modem unit 350 for demodulating the received I and Q signals, Receive switching unit 390 for separating the PCM signal 24 and the compressed signal 25 and the control signal 27 from the demodulated signal, The compressed The digital signal processing processor 380 converts the signal 25 into a PCM signal 26, the control processor 340 for receiving and analyzing the control signal 27, and the PCM signal 24 are transmitted to the data subscriber device. Or a subscriber unit 310 for converting the PCM signal 26 into voice and transmitting the same to a voice subscriber device.

When the high frequency unit 370 converts the radio frequency signal transmitted from the counterpart subscriber into an intermediate frequency signal, the distribution unit 365 distributes the intermediate frequency signal in two paths. The modem unit 350 receives the two divided signals as an I signal and a Q signal, respectively, and demodulates the received signal. The demodulated signal is a time division multiplexed signal of the PCM signal, the compressed signal, and the control signal. The reception first selector 430 of the reception switching unit 390 separates the demodulated signal transmitted through one communication path for each time slot. Receiving first selector 430 is the signal 24 of the first timeslot to the receiving second selector 440, signal 25 of the second timeslot to the digital signal processor 380, the third timeslot Signal 27 is transmitted to the control processor, respectively. The digital signal processing processor converts the ADPCM or LD-CELP signal 25 transmitted through the second timeslot into the PCM signal 26, and transmits the converted PCM signal 26 to the receiving second selector 440. .

The receiving second selector 440 transmits the PCM signal 24 or the PCM signal 26 to the subscriber unit 310 according to the service type of the counterpart subscriber device under the control of the control processor 340. The subscriber unit 310 connects the received signal to the voice subscriber device or the data subscriber device according to the service type of the counterpart subscriber device.

The present invention can be variously modified and can take various forms and only the specific embodiments thereof are described in the detailed description of the invention. It is to be understood, however, that the present invention is not limited to the specific forms mentioned in the detailed description of the invention, but rather includes all modifications, equivalents, and substitutions within the spirit and scope of the invention as defined by the appended claims. It should be understood to do.

In the present invention operating as described above, the effects obtained by the representative ones of the disclosed inventions will be briefly described as follows.

The present invention can reduce the unit cost and volume of the terminal by using a digital signal processing processor for voice compression, and can also expand the capacity of the wireless voice channel by using LD-CELP instead of ADPCM. In addition, the present invention can switch the voice channel using the switching unit, it is possible to efficiently use the communication path.

Claims (12)

A wireless subscriber network system for wirelessly connecting subscriber lines between a fixed base station and a subscriber device, A subscriber unit for converting a voice received from the voice subscriber device into a first PCM signal or receiving a second PCM signal from the data subscriber device; A digital signal processing processor for compressing the first PCM signal into a compressed signal by an ADPCM or LD-CELP scheme; A control processor for generating a control signal for communication between the terminal and the base station; A transmission switching unit configured to transfer the first PCM signal to a digital signal processing processor, and to multiplex the second PCM signal, a compressed signal transmitted from the digital signal processing processor, and a control signal transmitted from a control processor; A modem unit for modulating the multiplexed signal into I and Q signals; A combiner for combining the modulated I and Q signals; And a high frequency unit converting the combined signal into a radio frequency and transmitting the radio frequency through a transmission antenna. The terminal of claim 1, wherein the control processor controls a switching function of the switching unit and a modulation function of the modem unit. 2. The transmission switch of claim 1, wherein the transmission switching unit transmits the PCM signal transmitted from the subscriber unit through a first timeslot of a call path, and the compressed signal transmitted through the digital signal processing processor is transmitted through a second timeslot. The control signal transmitted from the control processor is transmitted through the third timeslot. The terminal of claim 3, wherein the transmission switching unit transmits a signal transmitted from an additional subscriber device through a fourth timeslot. The method of claim 1, wherein the transmission switching unit, A transmitting first selector for transmitting a first PCM signal transmitted from a voice subscriber device through the subscriber unit to a digital signal processing processor, and for transmitting a second PCM signal transmitted from the data subscriber device through the subscriber unit to another selector; And a transmission second selector for multiplexing the second PCM signal transmitted from the transmission first selector and the compressed signal transmitted from the digital signal processing processor and the control signal transmitted from the control processor to a modem unit. Terminal. A wireless subscriber network system for wirelessly connecting subscriber lines between a fixed base station and a subscriber device, A high frequency unit receiving a radio frequency signal through a receiving antenna and converting the radio frequency signal into an intermediate frequency signal; A divider for distributing the converted signal into I and Q signals; A modem unit for demodulating I and Q signals; A reception switching unit that separates the demodulated signal into a second PCM signal, a compressed signal, and a control signal; A digital signal processor for restoring the compressed signal to a first PCM signal by an ADPCM or LD-CELP scheme; A control processor for receiving and analyzing the control signal; And a subscriber unit for transmitting the second PCM signal to a data subscriber device or converting the first PCM signal to voice and transmitting the voice signal to a voice subscriber device. The terminal of claim 6, wherein the control processor controls a switching function of the switching unit and a demodulation function of the modem unit. The method of claim 6, wherein the receiving unit, the signal transmitted through the first time slot is separated into a PCM signal, the signal transmitted through the second time slot is separated into a compressed signal, and through the third time slot And a signal transmitted is separated into a control signal. The terminal of claim 8, wherein the reception switching unit transmits a signal transmitted through a fourth timeslot to an additional subscriber device. The method of claim 6, wherein the receiving switching unit, The signal transmitted from the modem unit is separated into a second PCM signal, a compressed signal and a control signal, the second PCM signal is transmitted to another selector, the compressed signal is transmitted to the digital signal processor, and the control signal is the control. A receiving first selector for transferring to the processor; And a receiving second selector for transmitting to the subscriber part a second PCM signal transmitted from a receiving first selector or a first PCM signal transmitted from a digital signal processing processor. A wireless subscriber network system for wirelessly connecting subscriber lines between a fixed base station and a subscriber device, A subscriber unit for converting a voice signal transmitted from the subscriber device into a PCM signal by pulse code modulation (PCM); A digital signal processing processor for compressing the PCM signal by an adaptive differential PCM (ADPCM) scheme or a low delay code excitation linear prediction (LD-CELP) scheme; A modem unit for modulating the PCM signal and the compressed signal into an intermediate frequency signal; A high frequency unit converting the intermediate frequency signal into a radio frequency signal and transmitting the radio frequency signal to an antenna; And a control processor for controlling a modulation function of the modem unit. A wireless subscriber network system for wirelessly connecting subscriber lines between a fixed base station and a subscriber device, Determining a service type of a subscriber device connected to the terminal; If the subscriber device is a voice subscriber device generating a voice signal, the digital signal processing processor converts the first pulse code modulation (PCM) signal transmitted through the subscriber unit into an adaptive differential PCM (ADPCM) scheme or a low delay code excitation linear prediction (LD−). Compressing the signal into a compressed signal by a CELP) scheme; If the subscriber device is a data subscriber device generating digital data, bypassing the second PCM signal transmitted through the subscriber unit; and Transmitting the compressed signal and the second PCM signal.