This Members only report provides an introduction to LDM, which is a technique enabling the simultaneous delivery of two independent broadcasting services in one terrestrial RF channel.
This Members only report provides an introduction to LDM, which is a technique enabling the simultaneous delivery of two independent broadcasting services in one terrestrial RF channel.
Layered Division Multiplexing (LDM) is a way of multiplexing two signals in a single RF TV channel in order to enable simultaneous delivery of two streams conveying independent or complementary broadcast services. This is possible by using spectrum overlay and signal cancellation techniques.
Simulations and laboratory measurements have proven that LDM offers an efficient and flexible approach to deliver high quality services, e.g. HDTV and UHDTV, simultaneously to portable indoor/mobile and fixed receivers using a single 8 MHz UHF channel. The gain with respect to Time Division Multiplexing systems is in the range from 5 to 9 dB depending upon the specific configuration.
LDM has been included as a part of the baseline (mandatory) ATSC 3.0 standard tools, and is a matter of technical discussion in other standardization and broadcast entities such as FOBTV.
Despite the fact that LDM can be used in a variety of application scenarios, the most immediate use case is the simultaneous delivery of UHDTV signals and ultra-robust mobile/portable indoor HD services using a single UHF channel.
Translations
The following translations of this document are available. Please note the translations may not be based on the latest version; see the year mentioned in brackets. These translations are courtesy of the translaters and hosted by the EBU 'as is'. The official and definitive version is the EBU English version.
Russian version of EBU BPN 107 [2016] - Special thanks to EBU Member RTR.
