发明授权
- 专利标题: Digital time-multiplexed quadrature frequency upconverter
- 专利标题(中): 数字时分复用正交频率上变频器
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申请号: US256420申请日: 1988-10-12
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公开(公告)号: US5101418A公开(公告)日: 1992-03-31
- 发明人: David N. Critchlow , Graham M. Avis , Sandra J. K. Earlam , Karle J. Johnson , Bruce A. Smetana , Gregory L. Westling , Eric Paneth , Moshe Yehushua
- 申请人: David N. Critchlow , Graham M. Avis , Sandra J. K. Earlam , Karle J. Johnson , Bruce A. Smetana , Gregory L. Westling , Eric Paneth , Moshe Yehushua
- 申请人地址: PA Philadelphia
- 专利权人: International Mobile Machines Corporation
- 当前专利权人: International Mobile Machines Corporation
- 当前专利权人地址: PA Philadelphia
- 主分类号: H04B7/26
- IPC分类号: H04B7/26 ; H03D3/00 ; H03D7/16 ; H03H17/06 ; H03L7/095 ; H04B1/38 ; H04B1/50 ; H04B7/005 ; H04L27/152 ; H04L27/18 ; H04L27/22 ; H04L27/233 ; H04M1/00 ; H04M1/253 ; H04M1/725 ; H04M11/06 ; H04Q7/20 ; H04Q7/38
摘要:
A digital wireless subscriber telephone unit for wireless connection with a base station. The subscriber unit has a baseband processor which is coupled to a storage for the baseband functions. The baseband processor is direct access coupled to a modem processor whereby the two processors may communicate with each other. The modem processor generally acts as the master in the system, although lock-out device may be used in certain circumstances. The signal from the modem processor is converted to an analog signal, which is subjected to deglitching, and the deglitched signal is then upconverted and filted to form an IF signal which is thereafter amplified. The amplified IF signal is combined with a signal generated by a synthesizer to provide an RF signal. On the basis of certain signals received from the base station, the baseband processor produces initiating signals which determine whether the subscriber unit will be in the transmit mode or the receive mode. In intervals between actuation of the system, a training mode is used wherein a known signal from the modem processor is compared with a looped-back signal to produce correction constants to compensate for undesirable variations of the IF, these constants being stored for use in correcting actual received signals. During demodulation, the modulated digital signals are fed to the modem processor in the form of time multiplexed I and Q samples and are demultiplexed. The demultiplexed I and Q samples are fed to an equalizer and frequency correction circuit for minimization of errors and for production of a frequency correction signal which is used to correct any errors in the timing of the system and in the output of the synthesizer.
公开/授权文献
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