Transmission experiment in urban areas
Following the 8K transmission experiment conducted in Hitoyoshi City, Kumamoto Prefecture, we are conducting transmission tests using an experimental transmitting station installed at NHK STRL in order to evaluate the transmission characteristics in urban areas. In this exhibit, you can view, in real time, the video received at the NHK Broadcasting Center 8 km away.
For a modulation scheme with many signal points such as 4096QAM*1, adjusting the distance between signal points to equalize the error rate of each bit of the symbol can enhance robustness against noise compared with the conventional modulation scheme in which signal points are distributed uniformly.
Stable reception can be ensured even in a mobile reception environment by using a decoding technology that compares actual reception signal points and all possible point candidates and selects the most probable signal point candidate.
We are continuing our study on transmission technologies for the next-generation of terrestrial broadcasting considering compatibility between 8K Super Hi-Vision broadcasting services for fixed receivers and Hi-Vision services for mobile receivers as well as the development of transmitting networks.
*1 QAM (Quadrature Amplitude Modulation): A digital modulation scheme that conveys information on the amplitude and phase of a carrier.
*2 MIMO (Multiple-lnput Multiple-Output): A wireless transmission scheme that uses multiple antennas each for transmission and reception.
*3 OFDM (Orthogonal Frequency Division Multiplexing): A transmission scheme that arranges multiple carriers orthogonal to each other on the frequency