Method and apparatus for acoustic echo cancellation in a communication system providing TTY/TDD service
AssigneeSamsung Electronics Co., Ltd.
InventorsJung-Woo Ku, Byung-Gun Park
Life of this patent
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Abstract
A method and apparatus are disclosed for canceling acoustic echo generated during transmission of text information in a communication system supporting a TTY/TDD service. When a mobile-to-land call is established between a mobile subscriber and a PSTN subscriber, a decoder notifies an encoder of detection of TTY/TDD text in a BS vocoder. The encoder then transmits a packet having silence information, which prevents acoustic echo reproduction of the text in the TTY/TDD device.
Claims14
A method for canceling acoustic echo generated from a public switched telephone network (PSTN) during transmission of text information from a base station (BS) to the PSTN in a communication system having the BS, a mobile station (MS) connected wirelessly to the BS, having a teletype/telecommunications device for the deaf (TTY/TDD) device for transmitting and receiving text information, the PSTN, a mobile switching center (MSC) for connecting the BS to the PSTN, and a land phone connected to the PSTN by cable, the method comprising:
- determining whether a data signal is inputted from the MS, the data signal is transmitted to the BS, and the transmitted data signal comprises text information, when a call between the MS and the land phone is set and the data signal is Generated from the TTY/TDD device;
- generating a blank packet including silence information in the BS if the text information is detected in the transmitted data signal;
- and
- transmitting the blank packet to the TTY/TDD device of the MS for canceling acoustic echo generated from the land phone.
A device for canceling acoustic echo generated from a public switched telephone network (PSTN) during transmission of text information from a base station (BS) to the PSTN in a communication system having the BS, a mobile station (MS) connected wirelessly to the BS, having a teletype/telecommunications device for the deaf (TTY/TDD) device for transmitting and receiving text information, the PSTN, a mobile switching center (MSC) for connecting the BS to the PSTN, and a land phone connected to the PSTN by cable, the device comprising:
- a detector adapted to determine whether a data signal from the TTY/TDD device is transmitted and received through the MS, and text information is included in the received data signal;
- and
- a packet generator adapted to generate a blank packet including silence information responding to the result of the detector and to transmit the blank packet to the TTY/TDD device through the MS for canceling acoustic echo generated from the land phone.
A device for canceling acoustic echo generated from a second mobile station (MS) during transmission of text information from a first teletype/telecommunications device for the deaf (TTY/TDD) device to a second TTY/TDD device in a communication system when a transcoding call between a first mobile station (MS) and the second MS is established and a data signal is generated from the first TTY/TDD device, the communication system comprising a first base station (BS), a second BS, a mobile switching center (MSC) for connecting the first and second BSs, the first MS connected wirelessly to the first BS, the first MS having the first TTY/TDD device for transmitting and receiving text information, and the second MS connected wirelessly to the second BS, the second MS having the second TTY/TDD device for transmitting and receiving text information, the device comprising:
- a detector adapted to determine whether the data signal is received from the first BS, the received data signal is transmitted through the MS, and text information is included in the data signal transmitted in the second BS;
- a delay counter adapted to set a delay count and to perform the delay count operation responding to the determination result of the detector;
- and
- a mute signal generator adapted to generate a signal to mute a signal directed to the MSC according to the value of the delay count and output the generated signal.
Dependencies are inferred from the claim text.