The Study And Design Of Transform Card Of Satellite Pager

The service agent of each pager station adopts the satellite channel to solve the conflicting of pollution and covering of radio wave. However due to the difference of the interface devices, the gate which called transform card is need .So the task emerges as the times require.Radio Paging System and it principle are introduced simple in the paper. Then three schemes are demonstrated. Finally the design~ debug and test of transform card are present in detail.The design of transform card is divided into two part, software and hardware. The hardware of transform card is constituted by microchip 8XC 196 and peripheral chip such as 4N35 which is photo-electricity segregating~ 1CL232 which is transforming the levels chip 74LS 161 which is binary system counter~ 74LS 123 which is single stable trigger~ 74LS 595 which is shift register and so on, Which key technology is selfsynchronizing, namely clock is abstracted from input data. The assembly language of 8XC196 which have the high efficiency interruption is used to compare and match with POCSAG codes. This transform card can recognize the POCSAG code of different polarity and different rate.Debug and test indicate the scheme in the paper is feasible. The transform card is stronger than the old transform card on bit synchronizing and error correcting of the clock. However the BCH calibrating of the POCSAG code has not been included in the software due to the urgent times.