The development of interactive services through a network application Hybrid Fiber Coax (HFC) such as telephony, Internet access, and other high speed data services is certainly require a two-way transmission. Between 5-42 MHz bandwidth is allocated for upstream signals. The biggest problem lies in an HFC network upstream frequency spectrum. In the upstream direction is likely to arise that it contains high levels of noise caused by thermal noise, narrowband Ingres (Ingres narrowband), impulse noise (impulse noise) and microreflections which resulted in a multipath coaxial transmission line.
Design modeling physical layer upstream HFC network in the simulation process refers to DOCSIS 2.0 specifications. The design includes the RS coding, interleaver, scrambler and mapping. Then in the second model is a combination of DOCSIS 2.0 with OFDM systems. OFDM model consists of a block P / S, cyclic prefix, IFFT and FFT. While the HFC channel modeling is made by the generation of thermal noise, ingress noise, impulse noise, ingress noise and miroreflections.
OFDM Performance in HFC networks are good enough to compare DOCSIS QPSK modulation, occurs prossesing gain equal to 2-3dB. While in 16QAM modulation OFDM performance is worse, but only to the condition of channel noise ingress. Better throughput in OFDM QPSK modulation, while 16QAM OFDM throughput value for the channel extreme worse, because it never reaches a value of 100%.
Design modeling physical layer upstream HFC network in the simulation process refers to DOCSIS 2.0 specifications. The design includes the RS coding, interleaver, scrambler and mapping. Then in the second model is a combination of DOCSIS 2.0 with OFDM systems. OFDM model consists of a block P / S, cyclic prefix, IFFT and FFT. While the HFC channel modeling is made by the generation of thermal noise, ingress noise, impulse noise, ingress noise and miroreflections.
OFDM Performance in HFC networks are good enough to compare DOCSIS QPSK modulation, occurs prossesing gain equal to 2-3dB. While in 16QAM modulation OFDM performance is worse, but only to the condition of channel noise ingress. Better throughput in OFDM QPSK modulation, while 16QAM OFDM throughput value for the channel extreme worse, because it never reaches a value of 100%.