KR200291329Y1 - Wireless Modem Supporting Universal Serial Bus Interface - Google Patents

Abstract

The wireless modem according to the present invention supports a USB interface, and (a) an antenna used for transmitting and receiving electromagnetic signals, a receiver for demodulating the RF signal received from the antenna to create a baseband signal, and a baseband signal. A radio module including a transmitter for modulating a carrier signal and generating an RF signal, and (b) providing a receive data by decoding a baseband signal and encoding a transmission data to provide a baseband signal to a transmitter of the radio module. A baseband unit, and (c) USB interface logic that is responsible for the interface between the baseband unit and external electronic devices. The USB wireless modem of the present invention is a CDMA wireless modem, which can interface with a user identification module (UIM) and is applied to not only notebooks and PDAs but also desktop computers. More convenient mobile communication service can be implemented. Since the USB wireless modem of the present invention receives a power signal directly from an external electronic device such as a computer through a USB cable, a separate power supply unit is not required.

Description

Wireless Modem Supporting Universal Serial Bus Interface

The present invention relates to a wireless communication technology, and more particularly to a wireless modem supporting a USB interface.

With the increase of portable or mobile electronic devices, the development of technology in the wireless communication sector is expanding and the demand is increasing. A wireless modem is used for wireless communication of a mobile electronic device. Like a wired modem, a wireless modem functions to transmit and receive data to and from an electronic device such as a computer. Conventional wireless modems support the PCMCIA slot and the Compact Flash Slot. These two slots are installed in laptop computers and PDAs (Personal Digital Assistants), which are typical mobile devices, and are used for LAN card or memory expansion.

However, conventional wireless modems are expensive compared to wired modems mounted on desktop computers, but are very slow. For wireless modems in their class that support CDMA 2000 1x RTT (theoretical maximum speed of 153Kbps), conventional wireless modems are only 80Kbps or 90Kbps. In addition, the conventional wireless modem is limited in its application because it can be used only in some electronic devices such as notebook computers or PDAs.

An object of the present invention is to provide a wireless modem with a greatly improved data transmission and reception speed.

Another object of the present invention is to provide a wireless modem that can be applied to a variety of electronic devices, flexible to the environment of use of the electronic device.

Still another object of the present invention is to provide a wireless modem using power from an electronic device connected to the modem without using a separate power source for power supply of the wireless modem.

Another object of the present invention is to improve the ease of use of a wireless mobile communication service by providing a wireless modem that can be equipped with a UIM card.

1 is a block circuit diagram showing the overall configuration of a CDMA USB wireless modem according to the present invention.

Figure 2 is a block circuit diagram showing the overall hardware configuration of a USB wireless modem according to an embodiment of the present invention.

3 is a block diagram showing a configuration of a power supply unit of a CDMA USB wireless modem according to an embodiment of the present invention.

4 is a block diagram illustrating a field to which a CDMA USB wireless modem according to the present invention is applied.

<Description of Major Symbols in Drawing>

10: wireless module 20: baseband unit

30: USB interface logic 40: USB cable

50: USB connector 60: external electronic device

70: power supply 75: step-down converter

100: USB Wireless Modem 110: CDMA Processor

120: HKADC 130: RF interface

140: TX DAC 150: SBI

160: PLL 170: JTAG

180, 190: UART 200: Microprocessor

210: universal interface 220: USB controller

290: USB Transceiver 300: R-UIM

The wireless modem according to the present invention for achieving this purpose supports a USB interface, (a) an antenna used to transmit and receive electromagnetic signals, and a receiver for demodulating the RF signal received from the antenna to create a baseband signal And a transmitter for modulating a carrier signal using a baseband signal and generating an RF signal, and (b) a transmitter for decoding the baseband signal to provide received data and encoding the transmitted data to transmit the transmitter. A baseband unit for providing a baseband signal, and (c) USB interface logic that is responsible for the interface between the baseband unit and external electronic devices. The USB wireless modem of the present invention can interface with a user identification module (UIM), and is applied to desktop computers as well as laptops and PDAs. USB interface logic includes a USB controller and a USB transceiver that implement the USB protocol layer.

According to the present invention, the USB wireless modem includes a power supply unit for receiving a power signal directly from the external electronic device through a USB cable connected between the USB transceiver and the external electronic device to supply a power signal to the wireless module and the baseband unit. The power supply unit includes a plurality of LDO voltages having a step-down converter having an input terminal connected to a VBUS pin and a ground pin of a USB cable, and an input terminal connected to an output terminal of the step-down converter. Include a diverter.

Embodiment

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 is a block circuit diagram showing the overall configuration of a USB wireless modem according to the present invention.

The USB wireless modem 100 includes a wireless module 10, a baseband (baseband, or baseband) unit 20, and a USB interface logic 30. The radio module 10 includes an antenna 12, a receiver 14, and a transmitter 16. The antenna 12 transmits and receives an electromagnetic wave signal, and the receiver 14 and the transmitter 16 share one antenna 12 through a duplexer 18. The receiver 14 demodulates a radio frequency (RF) signal received from the antenna 12 to generate a baseband signal. The transmitter 16 modulates a carrier signal using the baseband signal and generates an RF signal. The wireless module 10 allows an external electronic device 60 such as a desktop computer or a notebook computer to be connected to a wireless communication network.

The baseband unit 20 provides the baseband signal to the transmitter 16 of the radio module 10 and receives the baseband signal from the receiver 14. The baseband unit 20 decodes the baseband signal to provide received data, and encodes the transmission data to provide the baseband signal to the transmitter 16.

The USB interface logic 30 is responsible for the interface between the baseband unit 20 and the external electronic device 60. USB (Universal Interface Bus) is an interface standard developed by Intel, Microsoft, Compaq, IBM, NEC, DEC, and Nortel to form a cooperative and standardized work. The wireless modem of the present invention supports both USB standard 1.1 and USB standard 2.0.

The USB cable 40 has four wires. Two of them supply power and the other two are used for data. The cable's 1 V _BUS pin and 4 ground pin are for power supply. Pins D ^- 2 and D ⁺ 3 are for data. The USB connector 50 includes an A plug of a downstream type and a B plug of an upstream type.

The external electronic device 60 includes a device capable of exchanging data with and processing data with another electronic device through the wireless modem 100 according to the present invention. The external electronic device 60 is, for example, as illustrated in FIG. 4. , Desktop computer 400, notebook computer 500, or PDA 600 (Personal Digital Assistance).

2 is a block diagram showing the overall hardware configuration of a USB wireless modem according to an embodiment of the present invention. In the USB wireless modem 100, the wireless module 10, the base vance unit 20, and the USB interface logic 30 are supplied with operating power through the power supply unit 70. The configuration and operation of the power supply unit 70 are described with reference to FIG. It will be described later with reference to 3.

In the radio module 10, the oscillator 13 and the frequency synthesizer 15 generate a carrier signal and provide it to the receiver 14 and the transmitter 16. On the other hand, the oscillator 13 may be configured with one crystal (X-tal) to generate a local oscillation signal for multiple frequencies and channels, and the oscillator 13 may be, for example, a voltage controlled temperature compensated crystal oscillator (VCTCXO; Voltage). Controlled Temperature Compensation Crystal Oscillator). It is also possible to provide multiple frequencies using the programmable frequency synthesizer 15 to support multi-channel and full-duplexer operation.

The receiver 14 of the wireless module 10 provides the RF signal received through the antenna 12 to the CDMA processor 110 as Rx I data and Rx Q data. CDMA uses spread spectrum technology to modulate signals by giving codes of low correlation to each subscriber channel within the same frequency band, and the receiving side must use the same codes used at the transmitting side. It refers to a radio access method that allows restoration, and multiple users can transmit and receive signals while sharing time and frequency. The CDMA processor 110 is, for example, Qualcomm MSM5100 is used, and the data modulation for CDMA communication It performs the role of data demodulation.

The HKADC 120 is a part of sampling and converting an analog signal into a digital signal and monitoring the temperature and voltage of the RF interface 130.

The RF interface 130 is connected to the oscillator 13 of the wireless module 10, the SBI RF controller 17 of the receiver 14, and the SBI RF controller 19 of the transmitter 16. The RF interface 130 amplifies and filters the CDMA RF signal of a specific channel introduced into the antenna, synthesizes the local frequency generated by the PLL 160, converts the intermediate frequency into an intermediate frequency, and then receives the SBI RF of the receiver 14. Sends a signal to the controller 17. In addition, the RF interface 130 filters and then amplifies the CDMA RF signal generated by the transmitter 16 and transmits the same to the antenna 12.

The TX DAC 140 converts data to be transmitted to the transmitter 16 of the wireless module 10 into an analog signal and transmits Tx I data and Tx Q data.

The SBI 150 is connected to the SBI interface inside the SBI RF controllers 17 and 19 of the wireless module 10, and the CDMA processor 110 is connected to the RF controllers 17 and 19 by using the SBI communication scheme. Allows you to monitor and control the status of

The PLL 160 generates a local frequency for the assigned CDMA channel as a phase locked loop circuit and supplies it to the wireless module 10.

Joint Test Advisory Group (JTAG) 170 is a kind of hardware interface for testing chips or substrates in a finished product. The JTAG 170 is connected to a modem debugging tool 230 together with a UART 1 chip 180 and a UART 2 chip 190. Programs running on a processor supporting the JTAG 170 may be controlled through the JTAG port of the processor. The UART chips 180 and 190 correspond to the core components of the serial communication port in the PC. Data is transmitted from 1 byte to 8 byte units. UART chips 180 and 190 convert the received bytes into voltage signals.

The microprocessor 200 is responsible for arithmetic inside the wireless modem 100 and communicating with external memory devices. For example, the microprocessor 200 loads a source program stored in a flash memory 240 to operate and drive the SRAM 250 in a static random access memory.

The general-purpose interface 210 includes general-purpose input / output, such as a low noise amplifier (LNA) on / off control 260 of a receiver, an up-mixer gain control 270 of a transmitter, and communication with an EEPROM 280. It is responsible for general communication using the port.

USB is an excellent architecture for connectivity to PC-structured systems. It is a serial interface sufficient to meet the requirements of recent and future PC platforms, and offers the advantages of high speed, bidirectional, isochronous and low cost. have. USB uses four shielded wires, two wires for powering and two data wires for differential data signals. USB sends data using Non Return to Zero Invert (NRZI) encoding, which includes a sync field to synchronize with the host clock or the receiver clock. The USB controller 220 may include an internal configuration block such as, for example, a serial interface engine, an endpoint zero controller, and an endpoint zero FIFO. The serial interface engine implements all of the USB protocol layers, including frame recognition and generation, parallel / serial conversion, bit-stuffing / destuffing, cyclic redundancy checks (CRC) check / generation, and packet ID (PID). Perform functions such as verification / generation, address recognition, and handshaking evaluation / generation. The functions of the USB controller 220 listed above may be implemented by cooperation of the microprocessor 200 and the USB controller 220.

The USB transceiver 290 is used to satisfy the electrical specifications of the USB standard. Different types of low-type USB data generated by the microprocessor 200 are converted into general types of USB D + and D-. It is responsible for calling the format and vice versa. The USB transceiver 290 uses both differential ended and single ended outputs, and the state of the transceiver bus is represented by a single-ended signal on D +, D-, or both. For example, the single-ended signal '0' or 'SE0' may be used as a signal for resetting the USB controller 220 when it lasts longer than 10mS.

Meanwhile, the wireless modem 100 of the present invention may interface with a user identification module 300 (UIM; User Identity Module). According to one embodiment of the present invention, a removable user recognition module (R-UIM; Removable UIM) is mounted in the UIM slot (not shown) to interface through the UART 2 chip 190. The UIM 300 is an extension of the Subscriber Identity Module (SIM), which implements the specifications for physical and electrical characteristics, user-card interface and terminal-card signaling protocols for the removable functionality of the module 300. . For example, a user having a mobile phone using a UIM card can use a UIM card containing his / her phone number and fee information as it is mounted in the UIM slot of the USB modem 100 as it is. Therefore, the inconvenience of having to subscribe to a new mobile carrier separately from the mobile phone possessed by the user every time a new purchase of a wireless modem card can be eliminated in the present invention structure.

The USB wireless modem 100 according to the present invention is different from the conventional wireless modem communicating with an external electronic device using a UART, and the external electronic device through the USB controller 220, the USB transceiver 290, and the USB cable 40. Communication with the device is established.

3 is a block diagram showing the configuration of the power supply unit 70 of the USB wireless modem according to an embodiment of the present invention. The power supply unit 70 uses a step-down converter 75 connected to the USB cable 40 and an output voltage of the step-down converter 75 as input voltages, and logic LDOs (Low) for supplying power to logic circuits, respectively. Drop-Out voltage regulator 72, RF RX LDO 74 connected to a wireless receiving circuit, RF TX LDO 76 connected to a wireless transmitting circuit, and RF PLL LDO 78 powering a wireless PLL circuit. It includes. A voltage of +5.0 V is provided to the step-down converter 75 through the VBUS pin 1 and the ground pin 4 of the USB cable 40. The step-down converter 75 converts an input voltage of +5.0 V to, for example, +3.7 V to reduce the voltage difference between the output voltage of the LDOs 72 to 78 and the input voltage of the LDO. Although the USB cable 40 can be directly connected to the LDOs 72 to 78 without using the step-down converter 75, the difference in the input / output voltage of the LDO is 2V and thus the voltage conversion due to the heat consumption of the LDO. Inefficient Unlike conventional voltage regulators, the LDO can produce the desired output voltage even when the difference between the output voltage and the input voltage is not large.

Figure 4 is a block diagram illustrating the application of the USB wireless modem according to the present invention, showing the versatility of the present invention. That is, the wireless modem 100 of the present invention may be applied to the desktop computer 400 as well as the notebook computer 500 or the PDA 600 which are general mobile devices. In addition, the USB wireless modem of the present invention can be utilized in various ways. When a modem user is in a mobile environment, a laptop computer 500 or a PDA 600 enables faster data communication than a mobile phone, and in a desk environment, a desktop computer 400 is much faster than a telephone modem. Data communication is possible.

Embodiments of the present invention have been described with reference to the drawings, which are intended to describe the present invention and are not intended to limit the scope of the rights. That is, the embodiments described with reference to the drawings and various modifications and variations are possible without departing from the spirit and scope of the present invention.

According to the present invention, by supporting the USB interface, the data transmission and reception speed is greatly improved as compared with the conventional wireless modem, and the diversity and versatility of the modem is realized. For example, in the case of the conventional wireless modem supporting the PCMCIA interface, the data receiving speed was about 80 Kbps or 90 Kbps on average, but the USB wireless modem of the present invention can achieve a data receiving speed of 110 Kbps or more, so that the data receiving speed is 30 % Improvement. The versatility and versatility of modems maximize their effectiveness in communications environments that support wireless networks over wired infrastructures.

In addition to these effects, since the USB wireless modem according to the present invention is supplied with power from the external electronic device connected thereto, there is no need for a separate power supply unit.

In addition, the present invention supports the interface with the UIM, it is possible to implement a more convenient mobile communication service.

Claims (10)

A wireless modem that supports the Universal Serial Bus (USB) interface. An antenna used to transmit and receive electromagnetic signals, a receiver for demodulating the RF signal received from the antenna to create a baseband signal, and a transmitter for modulating a carrier signal using the baseband signal and generating an RF signal. Wireless module, A baseband unit for decoding a baseband signal to provide received data and encoding transmission data to provide a baseband signal to a transmitter of the wireless module; And a USB interface logic that is responsible for the interface between the baseband unit and an external electronic device. 2. The USB wireless modem of claim 1, wherein the baseband unit includes a CDMA processor that performs data modulation and data demodulation for CDMA communication. The microprocessor of claim 1 or 2, wherein the baseband unit further comprises a microprocessor that is in charge of operations within a modem and communicates with a memory device, and the USB interface logic is a low type of a differential format generated by the microprocessor. And a USB transceiver for converting USB data into USB D + and D- formats of a general type. 3. The USB wireless modem of claim 1 or 2, further comprising a UART chip coupled with a modem debugging tool, the UART chip interfacing with a User Identity Module (UIM). The USB wireless modem of claim 1 or 2, wherein the external electronic device includes a notebook, a PDA, and a desktop computer. The USB wireless modem of claim 3, further comprising a USB controller connected to the USB transceiver and implementing a USB protocol layer. 7. The USB controller of claim 6, wherein the USB controller includes a serial interface engine, an endpoint zero controller, and an endpoint zero FIFO block, wherein the serial interface engine includes frame recognition and generation, parallel / serial conversion, bit-stuffing / inverse. Performing at least one of the following functions: bit-stuffing / destuffing, cyclic redundancy checks (CRC) checking / creation, packet ID (PID) verification / creation, address recognition, and handshaking evaluation / generation. USB wireless modem characterized by. A wireless modem that supports the universal serial bus (USB) interface. An antenna used to transmit and receive electromagnetic signals, a receiver for demodulating the RF signal received from the antenna to create a baseband signal, and a transmitter for modulating a carrier signal using the baseband signal and generating an RF signal. Wireless module, A baseband unit for decoding a baseband signal to provide received data and encoding transmission data to provide a baseband signal to a transmitter of the wireless module; A USB interface logic for handling an interface between the baseband unit and an external electronic device, the USB transceiver converting the low-type USB data of the differential format generated by the baseband unit to USB D + and D- formats of a general type; A USB controller implementing a USB protocol layer and connected to the USB transceiver; And a power supply unit receiving a power signal from the external electronic device through a USB cable connected between the USB transceiver and the external electronic device to supply a power signal to the wireless module and the baseband unit. The method of claim 8, wherein the power supply unit is a plurality of LDO (Low Drop) having a step-down converter having an input terminal connected to the VBUS pin, the ground pin of the USB cable, and an output terminal of the step-down converter -Out) USB wireless modem further comprises a voltage converter. 10. The apparatus of claim 9, wherein the plurality of LDO voltage converters comprise a logic LDO voltage regulator for powering a logic circuit of a wireless modem, an RF RX LDO connected to a wireless receiving circuit, an RF TX LDO connected to a wireless transmitting circuit, and a wireless PLL circuit. A USB wireless modem comprising an RF PLL LDO for powering on.