公开(公告)号：DE3855894D1

公开(公告)日：1997-06-05

申请号：DE3855894

申请日：1988-12-21

Applicant: QUALCOMM INC

Inventor： GILHOUSEN KLEIN ,  ANTONIO FRANKLIN ,  JACOBS IRWIN ,  WEAVER LINDSAY

IPC: G02B6/293 ,  G02B6/34 ,  G02B6/42 ,  H01S3/08 ,  H01S5/14 ,  H01S5/40 ,  H04B1/7136 ,  H04B7/212 ,  H04B10/155 ,  H04L5/16 ,  H04B7/26 ,  H04J3/26

Abstract: A message communication system employing one or more centralized communication stations transferring messages through Earth orbit repeater satellites to or from mobile terminals with at least one central communication station having a first transceiver for transmitting a first communication signal to one or more mobile terminals and at least one mobile terminal having a second transceiver for receiving the first communication signal and demodulating it, and for transmitting at a predetermined duty cycle of the second transceiver, a second communication signal to at least one of the central communication stations. The preferred duty cycle over which the second communication signal is transmitted is about fifty percent of the second transceiver duty cycle. The communication system uses Time Division Multiplexed (TDM) communication signals using a number of channels as designated address channels with the remainder being used for data transfer. Information transmitted on the address channels is used by terminals to determine both the presence of a message and its corresponding data transmission or reception channel. In addition the terminals use the reception of the first communication signal to adjust return link transmission frequency to compensate for transmission path errors. The alternating duty cycle allows mobile terminals to use a single set of local oscillators for both transmission and reception modes of operation. To decrease interference with other systems the present system employs a power dispersal modulation function to achieve the footprint of a video signal for high transfer rate digital communication signals.

公开(公告)号：DE3854092D1

公开(公告)日：1995-08-03

申请号：DE3854092

申请日：1988-12-21

Applicant: QUALCOMM INC

Inventor： GILHOUSEN KLEIN ,  ANTONIO FRANKLIN ,  JACOBS IRWIN

IPC: H04B7/212 ,  H04J3/00 ,  H04J3/16 ,  H04J3/24 ,  H04Q7/06 ,  H04Q7/08 ,  H04Q7/12 ,  H04Q7/18 ,  H04Q7/38 ,  H04B7/26

Abstract: A message communication system employing one or more centralized communication stations transmitting messages through Earth orbit relay satellites to mobile receivers utilizing Time Division Multiplexed (TDM) communication signals having signal time frames divided into a series of transmission channels. A predetermined number of the channels are designated as address channels with the remainder being used for data transfer. Information transmitted on the address channels is used by receivers to determine both the presence of a message and its corresponding data transmission channel. Each system receiver scans, and tracks only the communication signal address channels until a message addressed to that receiver is detected, at which time the selected receiver changes channels to the designated data channel for reception of the message. Thus, demodulation of the entire communication signal is not required and processing time and power is reduced for the typical waiting condition when messages are not being received. While a message is being received only a portion of the communication signal need to be received, demodulated and decoded. The decoded message is then displayed on a display screen or similar device for the recipient.