пятница, 7 октября 2011 г.

OFDM, COFDM: DRM+ (DRM-E)

DRM+ (DRM-E)
Ch - 213, PSK-4, Br - 400 Hz, Sh - 444.4(4) Hz, k = 1/9

Author: SergUA6 
Band Width ~95500 Hz
Baud Rate 400 Hz
n-Ary (PSK/MPSK) PSK-4
Count of Carriers 213
Step between carriers 444.4(4) Hz
ACF      100 ms
RX mode Source I/Q record




Sonograms:

pic.1 General view



pic.2 The main signal's parameters.




Diagrams:
pic.3 The constellation in the channel




pic.4 Detalization



Pictures:
pic.5 ACF of the signal.




DRM+(DRM-E) - DRM format for VHF broadcasting, it is intended to extrude the analogue decisions in this sphere. It posseses range of attractive advantages: the necessary band is about 95-96 kHz on the broadcast channel, the transmission till 4 of independed programs is possible in one channel.


The signal itself is the typical representative of OFDM tecnology. All the parameters are defined in SA easyly enough. The maximum technical speed for PSK-4 and 213 channeles is 170 kbit/sec. In reality, the real speed of data transmission is a bit lower (about 130-150 kbit/sec), at the expencse of usage of part of the channels and symbols as the pilot/service.


As far as i know, the prespective of this standard in Russia are *foggy* enough, this record sent by collegues from Europe.