KR20140052423A

KR20140052423A - Method and device of avoiding mutual interference between bluetooth and wi-fi with frequency division

Info

Publication number: KR20140052423A
Application number: KR1020120118506A
Authority: KR
Inventors: 황거훈
Original assignee: 현대모비스 주식회사
Priority date: 2012-10-24
Filing date: 2012-10-24
Publication date: 2014-05-07

Abstract

The present invention relates to a method for avoiding mutual interference between Bluetooth and WiFi, comprising the steps of: confirming whether a Wi-Fi channel is used in a Bluetooth connection in an AVN system of a vehicle that performs wireless communication using Bluetooth and Wi-Fi; Transmitting the Wi-Fi channel usage information; And setting a band to which the first frequency is added to the Wi-Fi use channel band as an unusable frequency.
According to the present invention, the problem of interference between Bluetooth and WiFi is solved by using the frequency division scheme. Accordingly, the data transmission speed is improved in Bluetooth and Wi-Fi communication, compared with the conventional technology using the time division scheme. Also, the 3wire part can be deleted between the Bluetooth module and the WiFi module, which can reduce the size of the product and change the design of the product. In addition, interference problems can be solved to provide users with high-quality communications in Bluetooth and Wi-Fi communications.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for avoiding mutual interference between a Bluetooth and a Wi-

The present invention relates to a method and an apparatus for avoiding mutual interference between Bluetooth and WiFi, and more particularly, to a method and apparatus for avoiding mutual interference between Bluetooth and WiFi using a frequency division method.

Bluetooth and Wi-Fi interference avoidance technology is a technology that reduces mutual frequency interference using Co-existence algorithm when mutual frequency interference occurs between Bluetooth and Wi-Fi in AVN product for automobile.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a conventional Bluetooth-WLAN connection.

The technique of conventional co-existence algorithm uses time division method. For example, when Bluetooth transmits (TX), this information is shared by WiFi, and when the Bluetooth is in the standby state and the Bluetooth is RX (reception), the WiFi performs TX (transmission). In order to share mutual information, the Bluetooth part and the Wi-Fi part can be connected with 3wire and can share the mutual state.

In addition, the conventional technology uses a method of minimizing the interference phenomenon caused by Bluetooth or Wi-Fi using a frame pattern for time-division-based interval allocation in Bluetooth and Wi-Fi system as in Application No. 10-2008-0065113.

However, in order to apply the Co-existence algorithm, the prior art must connect 3wire. In this case, when the Bluetooth module and the Wi-Fi module are physically far apart, an interface connection burden to the 3wire occurs. In addition, since the prior art uses a time division method of dividing the frame allocation on the time axis, there is a problem in that when one data transmission amount is large, the other data transmission speed is slowed down.

It is an object of the present invention to provide a method and an apparatus for avoiding mutual interference between Bluetooth and WiFi in which interference is solved by using a frequency division scheme and data transmission speed is improved when wireless communication is performed using Bluetooth and Wi- .

According to an aspect of the present invention, there is provided an apparatus for avoiding mutual interference between Bluetooth and WiFi, the apparatus comprising: a Bluetooth module unit for performing short-range wireless communication with a plurality of peripheral devices in an AVN system of a vehicle; A Wi-Fi module unit for performing short-range wireless communication with a plurality of peripheral devices independently of the Bluetooth module unit in the AVN system of the vehicle; And a control unit for controlling the Bluetooth module unit and the Wi-Fi module unit to avoid a band in which the Bluetooth module view adds a specific frequency to a Wi-Fi use channel band.

According to another aspect of the present invention, there is provided a method of avoiding mutual interference between Bluetooth and WiFi, comprising the steps of: confirming whether a Wi-Fi channel is used in a Bluetooth connection in an AVN system of a vehicle that performs wireless communication using Bluetooth and Wi-Fi; Transmitting the Wi-Fi channel usage information; And setting a band to which the first frequency is added to the Wi-Fi use channel band as an unusable frequency.

According to the present invention, the problem of interference between Bluetooth and WiFi is solved by using the frequency division scheme. Accordingly, the data transmission speed is improved in Bluetooth and Wi-Fi communication, compared with the conventional technology using the time division scheme. Also, the 3wire part can be deleted between the Bluetooth module and the WiFi module, which can reduce the size of the product and change the design of the product. In addition, interference problems can be solved to provide users with high-quality communications in Bluetooth and Wi-Fi communications.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a conventional Bluetooth-WLAN connection; FIG.
FIG. 2 is a block diagram of a device for avoiding interference between Bluetooth and Wi-Fi according to an embodiment of the present invention; FIG.
3 is a flowchart of a method of avoiding mutual interference between Bluetooth and Wi-Fi according to an embodiment of the present invention;
4 is a flowchart of a method for avoiding mutual interference between Bluetooth and Wi-Fi according to an embodiment of the present invention;

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art. To fully disclose the scope of the invention to a person skilled in the art, and the invention is defined by the scope of the claims. It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. As used herein, the terms " comprises, " and / or "comprising" refer to the presence or absence of one or more other components, steps, operations, and / Or additions.

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

2 is a block diagram of a mutual interference avoiding apparatus for Bluetooth and Wi-Fi according to an embodiment of the present invention. Referring to FIG. 2, the Bluetooth and Wi-Fi mutual interference avoiding apparatus includes a Bluetooth module 110, a Wi-Fi module 120, and a controller 130.

The Bluetooth module 110 performs short-range wireless communication with a plurality of peripheral devices in the AVN system of the vehicle. The Wi-Fi module unit 120 performs short-range wireless communication with a plurality of peripheral devices independently of the Bluetooth module unit 110 in the AVN system of the vehicle.

The controller 130 controls the Bluetooth module 110 and the Wi-Fi module 120 to avoid the band where the Bluetooth module 110 adds a specific frequency to the Wi-Fi use channel band.

According to the embodiment of the present invention, when the user connects the Bluetooth during Wi-Fi use, the controller 130 controls the Wi-Fi module 120 when the AVN system of the vehicle is connected to the Bluetooth module 110 while the Wi- And transmits the Wi-Fi use channel information to the Bluetooth module 110 if Wi-Fi is in use.

For example, when the WiFi uses 20 MHz per channel, the controller 130 recognizes the Bluetooth module 110 as a bluetooth useless frequency band (for example, 40 MHz band plus 20 MHz) plus the first frequency to the Wi-Fi used channel band To prevent Bluetooth from hopping in this band.

According to another embodiment of the present invention, when a user connects a Wi-Fi connection during Bluetooth use, the controller 130 controls the use of Bluetooth when the Bluetooth module 110 is ON and the AVN system of the vehicle is connected to the Wi-Fi module 120 And transmits the Wi-Fi connection channel information to the Bluetooth module unit 110.

For example, when the WiFi uses 20 MHz per channel, the controller 130 checks the channel to be used in the Wi-Fi by the Bluetooth module 110 and adds a second frequency different from the first frequency (for example, 10 MHz Is set to be recognized as a Bluetooth unusable frequency so that Bluetooth can not perform frequency hopping in this band.

According to an embodiment of the present invention, the controller 130 performs UART communication with the Bluetooth module 110 and SDIO communication with the Wi-Fi module 120.

UART communication is a kind of serial communication. Serial communication is roughly divided into two types asynchronous and synchronous. The asynchronous communication controller is generally referred to as a UART (Universal Asynchronous Receiver / Transmitter). The signal from the UART usually has the TTL signal level, so it is weak to noise and the communication distance is limited. The interface IC that receives this TTL signal and is strong against noise and goes away is called line driver / receiver. And RS422.

SDIO communication (Secure Digital Input / Output) is a communication method established by SDA (SD Association). SDIO communication is applied to various fields such as Bluetooth, wireless LAN, camera and memory card. The operation of SDIO is basically a synchronized command (CMD) by the synchronous clock and receives and analyzes the response (RSP) while receiving or receiving data (DAT). Commands and responses are sent over the CMD line and data is sent over the DAT lines.

- How to connect Bluetooth while using WiFi -

3 is a flowchart of a method of avoiding mutual interference between Bluetooth and Wi-Fi according to an embodiment of the present invention.

First, whether a Wi-Fi channel is used or not is checked (S210). For example, when a Wi-Fi channel is not used, the user can immediately connect the Bluetooth, and since the Wi-Fi module unit 120 is in the OFF state, no interference occurs between the Bluetooth and the Wi-Fi.

Next, if the Wi-Fi channel is used, the Wi-Fi channel use information is transmitted (S220). For example, when the Wi-Fi uses 20 MHz per channel, it transmits Wi-Fi channel usage information to the Bluetooth module unit 110.

Next, the band to which the first frequency is added to the Wi-Fi use channel band is set to be recognized as the Bluetooth useless frequency (S230). Specifically, if 20 MHz is added to the Wi-Fi use channel band and the 40 MHz band is set to be recognized as the Bluetooth useless frequency, Bluetooth can not perform frequency hopping in that band.

A guard band is a narrow frequency band that is not used between channels designated as an empty frequency band that is used to prevent excessive leakage of a radio signal from affecting other allocated bands.

That is, since the 40 MHz band is recognized as the guard band using the frequency division scheme, frequency hopping can not be performed, and mutual interference between the Bluetooth and the WiFi does not occur.

- How to connect WiFi while using Bluetooth -

4 is a flowchart of a method of avoiding mutual interference between Bluetooth and Wi-Fi according to an embodiment of the present invention.

First, whether or not the Bluetooth is used when the Wi-Fi is connected is checked (S310). For example, when the Bluetooth is not used, the user can directly connect the Wi-Fi and the Bluetooth module 110 is in the OFF state, so that there is no mutual interference between the Bluetooth and the Wi-Fi.

Next, if Bluetooth is used, information on Wi-Fi channel use is transmitted (S320). For example, when the Wi-Fi uses 20 MHz per channel, it transmits Wi-Fi channel usage information to the Bluetooth module unit 110.

Next, in step S330, a channel to be used in the Wi-Fi is identified and a band in which the first frequency and a second frequency different from the first frequency are added is recognized as the unusable frequency. Specifically, when 10 MHz is added to the Wi-Fi use channel band and the 30 MHz band is set to be recognized as the Bluetooth unusable frequency, Bluetooth can not perform frequency hopping in that band.

That is, since the 30Mhz band is recognized as a guard band by using the frequency division scheme, frequency hopping can not be performed, and mutual interference between Bluetooth and WiFi does not occur.

- Frequency Hopping Spread Spectrum -

(1) The frequency hopping scheme is a spectrum spreading scheme that separates networks by different hopping sequences in the same area. Frequency hopping is a typical spread spectrum modulation scheme with direct sequence modulation. Specifically, frequency hopping discretely shifts the carrier frequency in a pattern determined by a code sequence. This method can select one million different frequencies and is selected based on the information and codes transmitted by each.

(2) Transmission / reception method of frequency hopping

The frequency hopping scheme first divides a given bandwidth into a large number of hopping channels and allocates the primary modulated signals (intermediate frequencies) to different hopping channels in a predetermined order when converting a primary modulated signal (intermediate frequency) into an RF frequency band .

In this case, since the channel to which the signal is allocated is changed rapidly, the influence of noise such as multi-channel interference can be reduced. On the other hand, at the receiving end, the original signals are reconstructed by connecting the reception signals dispersed in the hopping channels in the same order as the transmission side.

(3) Operation principle and characteristic

The frequency hopping is a method of instantaneously hopping to one frequency according to the hopping code, transmitting for a very short time at that frequency, tuning to another frequency again, and repeating the same process as before. Synchronization is necessary. That is, the receiver must tune to a specific frequency at a specific time using the same code as the hopping code used for transmission in order to receive the signal. It is advantageous in that parts are relatively inexpensive and high output is not required because various spread spectrum systems can be used in the same place if the hopping code is different even if the same frequency is used, as much as possible to prevent radio interference or noise interference.

The foregoing description is merely illustrative of the technical idea of the present invention and various changes and modifications may be made without departing from the essential characteristics of the present invention. Therefore, the embodiments described in the present invention are not intended to limit the scope of the present invention, but are intended to be illustrative, and the scope of the present invention is not limited by these embodiments. It is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents, which fall within the scope of the present invention as claimed.

110: Bluetooth module module 120: WiFi module module
130:

Claims

A Bluetooth module unit for short-range wireless communication with a plurality of peripheral devices in an AVN system of a vehicle;
A Wi-Fi module unit for performing short-range wireless communication with a plurality of peripheral devices independently of the Bluetooth module unit in the AVN system of the vehicle; And
And a control module for controlling the Bluetooth module and the Wi-Fi module to avoid a band in which the Bluetooth module adds a specific frequency to a Wi-
And a Bluetooth < RTI ID = 0.0 > WiFi < / RTI >

The method according to claim 1,
When the Wi-Fi module is ON
When the AVN system of the vehicle is connected to the Bluetooth module, it is confirmed that Wi-Fi is used, and when the AVN system is in use, information on Wi-Fi use channel is transmitted to the Bluetooth module,
The Bluetooth module adds the first frequency to the Wi-Fi use channel band to set the band to be recognized as the Bluetooth inaccessible frequency
A device for avoiding interference between Bluetooth and WiFi.

The method according to claim 1,
When the Bluetooth module is ON
Wherein the Bluetooth module is connected to the AVN system of the vehicle and transmits the Wi-Fi connection channel information to the Bluetooth module,
The Bluetooth module adds a second frequency different from the first frequency to the channel band to identify a channel to be used by the Wi-Fi module, and sets the band to be recognized as a Bluetooth-
A device for avoiding interference between Bluetooth and WiFi.

The method according to claim 1,
The control unit performs UART communication with the Bluetooth module unit and performs SDIO communication with the Wi-Fi module unit
A device for avoiding interference between Bluetooth and WiFi.

In an AVN system of a vehicle that wirelessly communicates using Bluetooth and Wi-Fi,
Checking whether a Wi-Fi channel is used when the Bluetooth connection is established;
Transmitting the Wi-Fi channel usage information; And
Setting a band to which the first frequency is added to the Wi-Fi use channel band as a useless frequency
&Lt; RTI ID = 0.0 > Bluetooth < / RTI >

6. The method of claim 5,
Recognizing the band as the unusable frequency includes recognizing a band in which the first frequency is added to the Wi-Fi use channel band as a guard band using a frequency division scheme
A method for avoiding mutual interference between Bluetooth and Wi-Fi.

In an AVN system of a vehicle that wirelessly communicates using Bluetooth and Wi-Fi,
Confirming whether Bluetooth is used in connection with a Wi-Fi connection;
Transmitting the Wi-Fi connection channel information; And
Identifying a channel to be used in the Wi-Fi and setting a band in which the first frequency and a second frequency different from the first frequency are added to the channel band as an unusable frequency
And a method for avoiding mutual interference between Bluetooth and WiFi.

8. The method of claim 7,
Recognizing the unusable frequency as a usable frequency includes recognizing a band in which a first frequency and a second frequency different from the first frequency are added to a Wi-Fi use channel band as a guard band using a frequency division scheme
A method for avoiding mutual interference between Bluetooth and Wi-Fi.