A Study Of OFDM Technology Based On Coaxial Cable Operating At Gigabit

With the improvement of people’s living standard and the popularity of various networks equipment, people put forward more and more high demand for broadband internet, The EOC technology by coaxial cable for high-speed data transmission of Ethernet data can effectively solve the last mile access network bottleneck and become to current research focus. OFDM technology has ability to get high spectral efficiency, resist the multi-path effects and can effectively resist multi-path effects due to reflection in the Gigabit coaxial cable. So the article will study the OFDM key technologies as channel estimation and reducing high PAPR and time-domain and frequency-domain synchronous. On the basis enhance the performance of the system by improving the appropriate algorithm.On the basis of analysis the decision feedback principle and the channel estimation algorithm based the coding decision feedback. The paper constitutes an improved decision feedback algorithm by adding the phase transition detection and correction module. The simulation results show that the improved algorithm can avoid error transmission due to phase transition and reduce the system bit error rate and improve the communication efficiency of the system.On the basis of analysis the cause of the high PAPR and reduce PAPR algorithm by SLM, the paper combines SLM algorithm and limiting algorithm to propose a new SLM-C algorithm to reduce the high PAPR. And in the Matlab simulation platform make simulation difference of function of CCDF for four different algorithms and simulate the system bit error rate. Results show that the improved algorithm to reduce complexity without increasing the bit error rate.On the basis of analysis classic ML synchronization algorithm and a special training sequence for OFDM system, the paper combines ML algorithm and the repeat structure and conjugate symmetry of the special sequence to put forward a joint synchronization algorithm that it can make the time domain and frequency domain synchronization estimated at the same time. And make Frequency Offset Estimation simulation for Gaussian channel and Gigabit channel coaxial cable. Results show that the improved joint synchronization algorithm can ensure to detect the symbol synchronization position and improve the accuracy of the frequency estimation under Gigabit coaxial multi-path effects, expanding the frequency offset estimation range of the original algorithm to improve the fractional frequency offset estimation accuracy and precision, low complexity, can be widely used in the coaxial cable Gigabit communication.