Simulation Evaluation of BER Characteristics for M-PSK and M-QAM Modulations used in the Reverse Channel of Cable TV Nets

  • S. Sadinov Technical University of Gabrovo
  • K. Koichev Technical University of Gabrovo
  • P. Penchev Technical University of Gabrovo
  • K. Angelov Technical University of Gabrovo


A profile is drawn for the various types of square modulations, which are used in transmitting digital signals in the reverse channel of cable TV networks (CATV). The latter are attacked by disturbances, which deteriorate the quality of transmitted signals and cause errors in the digital flow. 32, 64, 128-QAM are also analyzed. Signal to noise ratio is calculated as a function of error probability. Based on the obtained results, it is possible to establish the dependence of the cable length sector on the transmission speed featured by different types of cables provided we have an allowable error coefficient. Simulation and experimental results are compared. Ill. 6, bibl. 12 (in English; summaries in English, Russian and Lithuanian).