发明名称 |
Offset quadrature phase shift keyed modulation circuit |
摘要 |
An improved quadrature phase shift key modulator circuit of the type which includes a non-linear amplifier in the transmitter and includes a frequency select logic circuit for receiving the in phase and quadrature phase digital data to be modulated onto a carrier frequency signal. The output of the frequency select circuit produces select signals that are coupled to the input of a digital carrier frequency generator. The digital carrier frequency generator synthesizes and increases, decreases, or leaves unchanged the carrier frequency as a representation of the data occurring on the in phase and quadrature phase input lines. The output of the digital carrier frequency generator is smoothed and converted to an analog signal which has a constant vector power magnitude during phase change. The constant vector power when amplified in a non-linear amplifier of the transmitter is not susceptible to regeneration of side lobes of the carrier signal, thus, provides a more narrow bandwidth modulated carrier frequency signal.
|
申请公布号 |
US5696795(A) |
申请公布日期 |
1997.12.09 |
申请号 |
US19950503954 |
申请日期 |
1995.07.19 |
申请人 |
UNISYS CORPORATION |
发明人 |
WILLIAMS, BRUCE HOWARD;GREEFF, ROY EDGAR;ARBANAS, GLENN ARTHUR |
分类号 |
H04L27/20;(IPC1-7):H04L27/20 |
主分类号 |
H04L27/20 |
代理机构 |
|
代理人 |
|
主权项 |
|
地址 |
|