发明名称 |
PSK MODEM SYSTEM HAVING IMPROVED DEMODULATION RELIABILITY |
摘要 |
<p>A modem system is disclosed which has improved reliability of detection of transmitted PSK data using a simple signal delay detection scheme. A transmission signal is produced in which repetitive digital time slots each contain phase encoded "mark" or "space" data. Each time slot includes a reference phase portion at at least one of a front and rear portion of the time slot. The phase of the transmitted signal changes in the remaining portion of each time slot in accordance with applied digital data. For a "mark" data signal the phase changes from a reference phase in a first direction to predetermined phase in a first half of the remaining portion of the time slot, and then back to the reference phase before the end of the time slot. For a "space" data signal the phase changes from the reference value in a second direction opposite the first to another predetermined value in a first half of the remaining portion of the time slot, and then back to the reference phase before the end of the time slot. A simple delay detection demodulation system is used to recreate the original digital signal.</p> |
申请公布号 |
CA1269714(A) |
申请公布日期 |
1990.05.29 |
申请号 |
CA19870542092 |
申请日期 |
1987.07.13 |
申请人 |
SUMITOMO ELECTRIC INDUSTRIES, LTD. |
发明人 |
SHIBANO, YOSHIZO |
分类号 |
H04L27/18;H04L27/20;H04L27/233;(IPC1-7):H04L27/18 |
主分类号 |
H04L27/18 |
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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