发明名称 |
SETT ATT ASTADKOMMA EN ICKE-LINJER NIVAOVERFORING I EN KOMPANDERAD DELTAMODULERINGSTALOVERFORINGSANLEGGNING SAMT ANORDNING FOR GENOMFORANDE AV NEMNDA SETT |
摘要 |
An apparatus for suppressing background noise in a companded delta modulated telephone system. The apparatus includes a comparator for comparing a signal related to the analogue input signal to an encoder of the system with a reference signal. The comparator provides an output to reduce the rate of occurrence of a succession of bits which cause companding within the encoder when the reference signal exceeds the other signal to the comparator. This is achieved by altering the step size of a feedback signal within the encoder or modifying the output from the encoder by removing or inverting one of the compand bits. The reference signal is higher than a signal generated by background noise and consequently for signals below the reference signal the decoder reconstructs an analogue signal which is lower in level than the input signal. A method for achieving the result is also claimed. |
申请公布号 |
SE399159(B) |
申请公布日期 |
1978.01.30 |
申请号 |
SE19740003804 |
申请日期 |
1974.03.21 |
申请人 |
L M * ERICSSON PTY LTD |
发明人 |
P L * SMITH |
分类号 |
H04M11/00;H03G7/00;H03M3/02;H04B14/06;H04M1/253;H04M9/00;(IPC1-7):03K13/22 |
主分类号 |
H04M11/00 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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