Digital transmission error reduction
AssigneeBell Telephone Laboratories, Incorporated
InventorNuggehally S. Jayant
Life of this patent
Estimating the term…
Abstract
In a transmission system, reconstruction of a portion of the signal lost in transmission is based on signal encoding at the transmitter, and decoding at the receiver; at the transmitter, sequential portions of the signal are intermixed to form encoded portions, and autocorrelation factors (waveform feature signals) of the original portions are added to each encoded portion to form a packet; at the receiver, any missing packet is reconstructed from the adjacent received packet.
Claims32
A signal processing arrangement comprising:
- means for receiving an input signal;
- and means for converting segments of said input signal into coded signal packets
- characterized in that
- said converting means (110) comprises means (103, 105) responsive to said input signal for generating a sequence of coded signals;
- means (103, 105) responsive to the sequence of coded signals for forming coded signal blocks, each block corresponding to an input signal segment;
- means (109) for dividing each block of coded signals into a plurality of groups;
- means (111) responsive to the coded signals of each block for generating a signal representative of a waveform feature of the corresponding input signal segment, the waveform feature signal of each block being adapted to modify one coded signal group of the block to approximate another coded signal group of the block;
- and means (115) for combining the waveform feature signal of each block with each coded signal group of said block to form said coded signal packets.
A method for processing signals comprising the steps of receiving an input signal, and converting segments of said input signal into coded signal packets
- characterized in that
- said input signal converting step comprises generating a sequence of coded signals responsive to said input signal;
- arranging the sequence of coded signals in successive coded signal blocks, each block corresponding to an input signal segment;
- dividing each block of coded signals into a plurality of groups;
- generating a signal responsive to the coded signals of each block representative of a waveform feature of the segment of the input signal corresponding to the block, the waveform feature signal of each block being adapted to modify one coded signal group of the block to approximate another coded signal group of the block;
- and combining the waveform feature signal of each block with each coded signal group of said block to form said coded signal packets.
A speech signal communication system comprising means for receiving an input speech signal, means for converting segments of said input speech signal into successive coded signal packets;
- and means for applying said coded signal packets to a communication channel;
- said converting means comprising means responsive to said input speech signal for generating a sequence of coded signals;
- means responsive to the sequence of coded signals for forming coded signal blocks, each block corresponding to an input speech signal segment;
- means for dividing each block of coded signals into a plurality of groups;
- means responsive to the coded signals of each block for generating a signal representative of a waveform feature of the corresponding input signal segment, the waveform feature signal of each block being adapted to modify one coded signal group of the block to approximate another coded signal group of the block;
- and means for combining the block waveform feature signal of each block with each coded signal group of said block to form said coded signal packets.
In a speech communication system, a method for processing speech signals comprising the steps of receiving an input speech signal;
- converting segments of said input speech signal into successive digitally coded signal packets;
- and applying said digitally coded signal packets to a communication channel;
- said input speech signal converting step comprising the steps of generating a sequence of coded signals responsive to said input signal;
- forming coded signal blocks responsive to the sequence of coded signals, each block corresponding to an input speech signal segment;
- dividing each block of coded signals into a plurality of groups;
- generating a signal responsive to the coded signals of each block representative of a waveform feature of the corresponding input signal segment, the waveform feature signal of each block being adapted to modify one coded signal group of the block to approximate another coded signal group of the block;
- and combining the waveform feature signal of each block with each coded signal group of said block to form said coded signal packets.
A signal processing system in which a signal is represented by successive blocks of coded signals, each coded signal block corresponding to a waveform segment is divided into a plurality of groups, and each group is combined with a signal representative of a waveform feature of the corresponding segment to form a coded signal packet, the waveform feature signal of each block being adapted to modify one coded signal group of the block to approximate another coded signal group of the block, said signal processing system comprising
- means for receiving coded signal packets;
- means for assembling the coded signal packets of said block;
- means responsive to said assembled block coded signal packets for detecting the absence of a block coded signal packet;
- and
- means responsive to the operation of said detecting means for generating a set of signals representative of the coded signal group of the absent coded signal packet responsive to the block waveform feature signal and at least one other coded signal group of the block.
A method for processing signals in which a signal is represented by successive blocks of coded signals, each coded signal block corresponding to a waveform segment is divided into a plurality of groups, and each group is combined with a signal representative of a waveform feature of the corresponding segment to form a coded signal packet, the waveform feature signal of each block being adapted to modify one coded signal group of the block to approximate another coded signal group of the block, said signal processing method comprising the steps of receiving coded signal packets;
- assembling the coded signal packets of said block;
- detecting the absence of a block coded signal packet responsive to said assembled block coded signal packets;
- generating a set of signals representative of the coded signal group of the absent coded signal packet responsive to the block waveform feature signal and at least one coded signal group of the block.
Dependencies are inferred from the claim text.