Digital transmission system with improved decoder in the receiver
AssigneeU.S. Philips Corporation
InventorsRudolf Hofmann, Wolfgang Brox
Life of this patent
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Abstract
A digital transmission system, such as a mobile radio system, having a transmitter for transmitting codewords which are derived from a digital signal, and a receiver for receiving codewords, the receiver including a decoder with a prediction filter which is excited by an input signal to produce an estimated digital signal. To improve reconstruction of the digital signal in the event of disturbances, the decoder includes a first switching circuit for switching off the input signal of the prediction filter when a disturbed codeword is received, and a second switching circuit for switching substitute values formed from previous values of the estimated digital signal instead of the estimated digital signal when the input signal is switched off.
Claims12
A digital transmission system comprising:
- a transmitter, having an input for receiving a digital signal, for transmitting codewords derived from the digital signal, and
- a receiver, comprising an input for receiving codewords transmitted by the transmitter, and a decoder for decoding the received codewords, the decoder including a prediction filter, the prediction filter being excited by an input signal based on the received codewords and producing an estimated digital signal, characterized in that the decoder comprises:
- first switching means for switching off the input signal excitation to the prediction filter when a disturbed codeword is received at the receiver input, and
- second switching means for substituting substitute values formed from previous values of the estimated digital signal, instead of an estimated digital signal based on the disturbed codeword, when the input signal excitation is switched off.
A mobile radio system transceiver, comprising:
- a receiver, having an input for receiving transmitted first codewords derived from a first digital signal, and a decoder for decoding the first codewords, the decoder including a prediction filter, the prediction filter being excited by an input signal based on the first codewords and producing an estimated digital signal, and
- a transmitter, having an input for receiving a second digital signal, for transmitting second codewords derived from the second digital signal,
- characterized in that the decoder comprises:
- first switching means for switching off the input signal excitation to the prediction filter when a disturbed codeword is received at the receiver input, and
- second switching means for substituting substitute values formed from previous values of the estimated digital signal, instead of an estimated digital signal based on the disturbed codeword, when the input signal excitation is switched off.
A digital mobile radio system receiver comprising:
- an input for receiving transmitted codewords derived from a digital signal, and
- a decoder for decoding the received codewords, the decoder including a prediction filter, the prediction filter being excited by an input signal based on the received codewords and producing an estimated digital signal, characterized in that the decoder comprises:
- first switching means for switching off the input signal excitation to the prediction filter when a disturbed codeword is received at the receiver input, and
- second switching means for substituting substitute values formed from previous values of the estimated digital signal, instead of an estimated digital signal based on the disturbed codeword, when the input signal excitation is switched off.
Dependencies are inferred from the claim text.