Patent ID: 7567814

Claim:
In a radio transmission system comprising a transmitter comprising a coding device and a receiver comprising a decoding device, the transmitter transmitting a packet outputted from the coding device by radio through a transmission buffer, the receiver notifying, when it has normally received the packet, the transmitter that it has normally received the packet, and the transmitter which has been notified that the receiver has normally received the packet erasing only the packet from the transmission buffer, a radio transmission system wherein the transmitter comprises means for adding to the packet outputted from the coding device transmitter-side time information representing the time on the side of the transmitter when the packet is outputted from the coding device, means for storing in the transmission buffer the packet having the transmitter-side time information added thereto, and means for transmitting the packet stored in the transmission buffer at predetermined time intervals, and the receiver comprises number-of-packet-arrivals counting means for updating a count value each time the packet transmitted for each predetermined time interval from the transmitter is received, multiplying means for multiplying the count value of the number-of-packet arrivals counting means by a packet transmission time interval determined on the side of the transmitter, adding means for generating a virtual time on the side of the transmitter by adding a predetermined offset value to a result of multiplication by the multiplying means, means for synchronizing the time on the side of the receiver with the time on the side of the transmitter by a PLL circuit on the basis of the virtual time on the side of the transmitter obtained by the adding means, means for holding the received packet in a receiving buffer, and means for outputting, when the time on the side of the receiver coincides with the time on the side of the transmitter which is represented by the transmitter-side time information added to the packet held in the receiving buffer, the packet to the decoding device.