Back to results
US 8,302,148 B2Granted
Transmission of composite digital broadcast information
AssigneeTelefonaktiebolaget L M Ericsson (publ)
InventorsJörg Huschke, Ralf Tönjes, Uwe Horn
Life of this patent
Estimating the term…
Abstract
To improve transmission of digital broadcast information, there is proposed a method of transmitting digital broadcast information from a main transmitter (12) to at least one repeater (14). There is generated a composite digital broadcast signal carrying first digital broadcast information according to a first digital broadcast specification (DVB-T) and second digital broadcast information according to a second digital broadcast specification (DVB-H). The composite digital broadcast is then broadcasted such that the second digital broadcast information (DVB-H) is sent in a transmission mode used for transmission of the first digital broadcast information (DVB-T).
Claims12
Method of operating a repeater for distribution of digital broadcast information, characterized by the steps:
- receiving a composite digital broadcast signal carrying first digital broadcast information according to a first digital broadcast specification (DVB-T) and second digital broadcast information according to a second digital broadcast specification (DVB-H), wherein the signal corresponding to the second digital broadcast specification (DVB-H) is overlaid onto a transmission signal carrying the first digital broadcast information using hierarchical modulation;
- and
- selectively forwarding either the composite digital broadcast signal or a digital repeater forwarding signal carrying the first digital broadcast information or the second digital broadcast information;
- wherein the step of deriving the digital repeater forwarding signal comprises the steps:
- determining a forwarding part (DVB-H) from the composite digital broadcast signal reflecting a first digital broadcast information or a second digital broadcast information;
- and
- deducting a non-forwarding part (DVB-T) from the composite digital broadcast signal for determination of the repeater digital forwarding signal;
- and,
- wherein the step of determining the forwarding part (DVB-H) comprises the steps:
- frequency shifting and demodulating the composite digital broadcast signal to a first repeater base-band signal;
- separating the first base-band signal into a first de-mapped broadcast bit stream reflecting the first digital broadcast information and a second de-mapped broadcast bit stream reflecting the second digital broadcast information by reversing a vector overlay step executed at the transmitter side assuming that
- first digital broadcast information (DVB-T) is mapped starting from the first channel coded broadcast bit stream onto one first constellation point of a plurality of constellation points in a first constellation diagram;
- second digital broadcast information (DVB-H) is mapped starting from the second channel coded broadcast bit stream onto one second constellation point of a plurality of constellation points in a second constellation diagram;
- and
- the base-band signal is generated by vector overlay of the first constellation point and the second constellation point;
- selecting the first constellation mapped broadcast bit stream or the second constellation mapped broadcast bit stream for forwarding from the repeater.
13 more elements
Repeater for distributing digital broadcast information to at least one mobile unit, characterized by:
- a receiver unit adapted to receive a composite digital broadcast signal carrying first digital broadcast information according to a first digital broadcast specification (DVB-T) and second digital broadcast information according to a second digital broadcast specification (DVB-H) wherein the signal corresponding to the second digital broadcast specification (DVB-H) is overlaid onto a transmission signal carrying the first digital broadcast information using hierarchical modulation;
- and
- a forwarding unit adapted to selectively forward either the composite digital broadcast signal or a digital repeater forwarding signal carrying the first digital broadcast information or the second digital broadcast information;
- wherein the forwarding unit comprises:
- a splitting unit adapted to determine a forwarding part (DVB-H) from the composite digital broadcast signal reflecting a first digital broadcast information or a second digital broadcast information;
- and
- a forwarding signal generation unit adapted to deduct a non-forwarding part (DVB-T) from the composite digital broadcast signal for determination of the digital repeater forwarding signal and,
- wherein the splitting unit comprises:
- a demodulation unit adapted to frequency shift and de-modulate the composite digital broadcast signal to a first repeater base-band signal;
- a separation unit adapted to separate the first base-band signal into a first constellation mapped broadcast bit stream reflecting the first digital broadcast information and a second constellation mapped broadcast bit stream reflecting the second digital broadcast information by reversing a vector overlay executed at the transmitter side assuming that
- first digital broadcast information (DVB-T) is mapped starting from the first channel coded broadcast bit stream onto one first constellation point of a plurality of constellation points in a first constellation diagram;
- second digital broadcast information (DVB-H) is mapped starting from the second channel coded broadcast bit stream onto one second constellation point of a plurality of constellation points in a second constellation diagram;
- and
- the base-band signal is generated by vector overlay of the first constellation point and the second constellation point;
- and
- a selection unit adapted to select the first constellation mapped broadcast bit stream or the second constellation mapped broadcast bit stream for forwarding from the repeater.
13 more elements
Dependencies are inferred from the claim text.