Arrangement for adapting the signal level in mobile phones

• US 5,797,102 A
• Filed: 09/10/1996
• Issued: 08/18/1998
• Est. Priority Date: 01/05/1994
• Status: Expired due to Term

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Mobile Phones UK Limited (Nokia Corporation)
• Inventors: Kattilakoski, Matti H. M., Hallikainen, Jyrki S., Korkeakangas, Pekka H. M.
• Primary Examiner(s): WOLFE JR, WILLIS RAY
• Application Number:
  US08/669,324
• Time in Patent Office: 707 Days
• Field of Search: 455/557, 455/558, 455/567, 455/568, 455/569, 455/68, 455/341, 379/165, 379/447
• US Class Current: 455/557
• CPC Class Codes: H04M 1/6075 adapted for handsfree use in a vehicle H04M1/6058 takes precedence; arrangements for holding telephones in a vehicle B60R11/0241
• CPC Class Codes: H04M 1/72409 by interfacing with external accessories hands-free H04M1/60
• CPC Class Codes: H04W 88/02 Terminal devices

Abstract

The object of the disclosure is an arrangement for adapting the signal level in mobile phones according to the related auxiliary device connected to the mobile phone. The microprocessor (MCU) of the mobile phone receives the connection data from the auxiliary device when the auxiliary device is connected to the mobile phone. In addition, the microprocessor comprises a memory in which the amplification data respectively required has been stored depending on the type of the auxiliary device. On the basis of this the microprocessor transmits the appropriate amplification data to the PCM-codec of the mobile phone and to its digital signal processor (DSP). Numerous auxiliary devices are viable, such as hands-free units, modems, telefaxes etc.

Claims

1. An arrangement for adapting the signal level in mobile phones according to the related auxiliary device connected, characterized in that the mobile phone is adapted to identify the type of auxiliary device respectively connected on the basis of a signal received from the auxiliary device, and adapted to adjust its internal signal levels to suitable levels according to the auxiliary device, and the mobile phone comprises memory means for storing signal level parameters related to the auxiliary devices.

2. An arrangement according to claim 1, characterized in that the interface between the mobile phone and the auxiliary device comprises a first signal line, through which the identification data of the auxiliary device is transmitted, and a second signal line which is used to transmit the audio signal, whereby, on the basis of the identification data received through the fist signal line, the mobile phone is adapted to adjust its internal signal levels related to said audio signal to fit the auxiliary device.

3. An arrangement according to claim 1 characterized in that the auxiliary device is adapted to transmit the identification message using the digital data bus of the telephone.

4. An arrangement according to claim 3, characterized in that the auxiliary device is adapted to repeatedly transmit messages to the telephone, using the digital data bus, and the telephone recognizes the disconnection of the auxiliary device on the basis of the missing message.

5. A circuit arrangement according to claim 1 characterized in that the auxiliary device comprises an electric component, such as a resistor, which is connected between the line used to identify the auxiliary device and called a hook-line in following, and a third line, the resistance comprising an impedance (resistance) specified according to the type of auxiliary device, and the mobile phone identifies the auxiliary device by supplying a current and/or a voltage between the hook-line and the third line and by measuring the voltage and/or current generated in the hook-line.

6. A circuit arrangement according to claim 5, characterized in that the mobile phone comprises an analog-to-digital converter for converting the voltage data of the hook-line into digital data, and the microprocessor reads the digital voltage value to identify the auxiliary device.

7. A circuit arrangement according to claim 6, characterized in that the microprocessor of the telephone repeatedly reads the digital voltage data to indicate a connection or disconnection of the auxiliary device.

8. An arrangement according to claim 1, characterized in that the connection/disconnection of the auxiliary device from the telephone interface causes a change in the state of an interrupt line, after which the microprocessor of the telephone carries out the identification of the auxiliary device.

9. A circuit arrangement according to claim 1, characterized in that the signal level parameters, which are used when no auxiliary device is connected or when no data of the signal level parameters related to the connected auxiliary device has been stored in the memory means, are stored in the memory means of the mobile phone.

10. A circuit arrangement according to claim 9, characterized in that the microprocessor reads from the memory means the signal level parameters related to the connected auxiliary device type or the signal level parameters related to the audio part of the mobile phone and sets the digital signal processor of the telephone and/or the amplification of the codec to values corresponding to the parameters read.