초록 ▼

A receiver for FM Multiplex broadcast packet communications is provided that includes a block identifying code (BIC) detection circuit which determines whether a received packet is a data packet type or a parity packet type based on predetermined BIC patterns. The receiver further includes block cou

A receiver for FM Multiplex broadcast packet communications is provided that includes a block identifying code (BIC) detection circuit which determines whether a received packet is a data packet type or a parity packet type based on predetermined BIC patterns. The receiver further includes block counter circuitry that counts blocks in a synchronized frame and determines whether a received packet is a data type or a parity type (D/P) based on the count value. An abnormality detection circuit detects discrepancies between these two D/P determinations and indicates a synchronization abnormality. In another embodiment, the BIC detection circuit provides an indication of a received BIC type (BIC1-BIC4) based on predetermined BIC patterns while the block counter circuitry determines the BIC type based on the counted number of the block in a synchronized frame. In this case, the abnormality detection circuit detects discrepancies between the two BIC type determinations and indicates a synchronization abnormality. A history of detected abnormalities is stored in an abnormal history memory circuit. If the number of abnormalities detected exceeds a predetermined threshold within a predetermined period, a packet offset determining circuit then generates a signal for canceling the frame-in-synchronism state and initiates a resynchronization process.

대표청구항 ▼

[ What is claimed is:] [1.] A receiver for receiving digital data multiplexed on FM multiplex broadcast signals wherein a packet of digital information is structured as either a data packet comprising a block of binary data bits or as a parity packet comprising a block of binary parity bits and a fr

[ What is claimed is:] [1.] A receiver for receiving digital data multiplexed on FM multiplex broadcast signals wherein a packet of digital information is structured as either a data packet comprising a block of binary data bits or as a parity packet comprising a block of binary parity bits and a frame comprises a plurality of packets, and wherein block synchronism of de-multiplexed data is determined at least in part by detecting a block synchronization code attached to the head of each packet and frame synchronism is determined at least in part by detecting a change in the block synchronization code occurring at predetermined blocks, said receiver comprising:block counter circuitry, said block counter circuitry composing a counter for counting packets in a synchronized frame of received data and producing a first signal indicative of whether a received packet is of a data packet type or a parity packet type based on predetermined block count values;a block identification code detection circuits said detection circuit comprising digital logic circuitry for detecting a block synchronization code in a received packet and producing a second signal indicative of whether a received packet is of a data type or a parity type based on predetermined synchronization code patterns; andan abnormality determining circuit, said determining circuit comprising digital logic circuitry for comparing said second signal indicative of packet type determined from said synchronization code with said first signal indicative of packet type determined by said counter circuitry and outputting an abnormality indication signal when said first and second signals indicate different packet types.