| 摘要 |
The invention relates to a method of frame synchronization of a digital time-division multiplex communication system and to an arrangement for performing the method. During the search for a synchronization pattern of M bits in frames, each consisting of N time slots, a shift register of NxM bits is usually used. The method according to the invention has for its object to reduce the number of bit storage capacity required. The method operates as follows. At the start of the synchronization process the first bit of the synchronization pattern is expected. If this expectation comes true, the second bit of the synchronization pattern is expected in that time slot in the immediately subsequent frame etc. If the expectation does not come true then the (partially) received pattern is no synchronization pattern and the procedure is performed again in that time slot. The method is based on the recognition that it is not necessary to store the partially received synchronization pattern in a store, but that it is sufficient to store the numerical order of the bit of the synchronization pattern expected in the time slot of the next frame. Consequently, a storage capacity of Nxentire log2 M is sufficient. The method can be performed with a microprocessor or with "wild" logic circuits.
|
