A system for combining AM and FM transmissions. In-band, On-channel, FM Digital Audio Broadcast (IBOC FM-DAB) allows simultaneous transmission of DAB and FM over existing FM allocations without interfering with conventional analog FM signals. The utility of existing FM spectrum allocations is therefore enhanced.

Detection of synchronization signals of digital broadcasting waves of respective reception systems is periodically carried out, and a relative time difference between synchronization timings of the synchronization signals is grasped. In the case where a synchronization signal can not be detected from the reception system under selection, the relative value is added to or subtracted from the generation timing of a synchronization signal of the other reception system, so that the synchronization t...

In a cable broadcasting system of the invention capable of setting output or stop of broadcasting-signals from tap output terminals of a tap device in response to a command signal transmitted by a center equipment, when demand for output setting for many tap devices occurs, output setting of the corresponding tap devices can be surely carried out without increasing the load on each power supply device for supplying the tap devices in each district with electricity. When demand for setting tap ou...

A receiver for selectively receiving either an FM-FM type television sound multiplex broadcasting or an FM-AM type FM stereo multiplex broadcasting includes a PLL (phase-locked loop) circuit for forming a 38 kHz switching carrier for demodulating an FM stereo multiplex signal during reception of the FM stereo multiplex broadcasting, which PLL circuit is concurrently used to attain various purposes in receiving the television sound multiplex broadcasting. In a first embodiment, the PLL circuit is...

A digital audio broadcasting receiver comprises a phase error detector for detecting a phase error from data from a differential demodulator, an average value processing unit for determining the average value of phase errors, a memory for storing the phase errors of the carriers outputted from the phase error detector, and a phase error correcting unit which excludes a phase error whose sign is opposite to that of the average value among the phase errors stored in the memory, and determined the ...

Frequency resources of a DME/TACAN band specified for the aircraft band are effectively utilized, and a GPS reinforcing data is overlapped onto distance information to be broadcast. A header is added to a DGPS reinforcing data, and the transmitting pulse level of a conventional ground DME system is modulated, and the data is broadcast to an airborne system. In the airborne system, a threshold value of "1" and "0" is generated by a level detecting device (5), and the start point of the data is de...

In order to descramble sections of scrambled data interleaved with sections of unscrambled data in a transport stream of broadcast video data, while leaving the sections with the original timing relationship in the transport stream, a common data flow path (1-5) is provided both for sections of scrambled data and sections of unscrambled data and signal path loops (6,7; 8,9) including cipher means (62,64) to enable the descrambling of scrambled data, and a control state machine for controlling th...

On the side of a transmitter in a digital broadcasting system, a multiplexed picture is produced by multiplexing a plurality of pictures using a frame memory device. A video encoder encodes the multiplexed picture so as to realize a prescribed correspondence between a field type (even, odd) and a displaying order. Thus, a plurality of encoded pictures having the GOP structure are produced. The encoded pictures are transmitted to a receiver in the digital broadcasting system by using a one-channe...

A broadcasting receiver for setting beforehand, a threshold of free disk space of a file system on a Hard Disk Drive (HDD), detection of record termination of a specified program investigates the free disk space of the HDD. The present free disk space is compared with the threshold level of free disk space set up beforehand. If the present free disk space is smaller than the threshold level, a message indicating the free disk space has decreased is displayed automatically, and, if necessary, the...

Apparatus and method of achieving diversity in reception of plural digital broadcast signals. A stream of a complete set of code bits is generated from one or more sources of data bits. A first Critical Subset of code bits is chosen or selected for a first channel (e.g. a specified puncturing pattern is applied to the stream of a complete set of code sets). A second (e.g. alternative) Critical Subset of code bits is chosen or selected for a second channel (e.g. a second or alternative puncturing...