Simulation-based performance analysis and improvement of orthogonal frequency division multiplexing - 802.11p system for vehicular communications

In this study, the physical layer (PHY) of the upcoming vehicular communication standard IEEE 802.11p has been simulated in vehicle-to-vehicle situation through two different scenarios. IEEE 802.11p wireless access in vehicular environment defines modifications to IEEE 802.11 to support intelligent transportation systems applications. The standard is being considered as a promising wireless technology for enhancing transportation safety and provides safety-related services like collision avoidance and emergency breaking. At first, this includes data exchange between high-speed vehicles and between the vehicles and the roadside infrastructure in the licensed ITS band of 5.9 GHz. Performance analysis of PHY model has been evaluated into different propagation conditions (AWGN, Ricean and Rayleigh fading). In particular, bit error rate (BER) and signal to noise ratio for all the data rates have been estimated. Simulation results reveal that our system can efficiently mitigate inter-symbol interference and inter-carrier interference introduced by multi-path delay spread in our high mobility environment but against frequency-selective fading BER values are on to increase. To overcome this problem, the authors propose to use a different value of guard interval (3.2 μs). Our initial results indicate that the performance with the larger cyclic prefix outperforms the performance of the initial value in our mobile channel profiles. Moreover, the authors investigated in which way the Doppler spread affects the performance with regard to the transmission distance.     

Performance of MIMO-WCDMA Multicellular Networks with Ideal Power Control

The goal of the study presented in this paper is to investigate the performance of a multiple input multiple output network using the wideband code division multiple access physical layer protocol. In this context, several transmission techniques are evaluated by executing independent Monte Carlo simulations in parallel with the help of a developed hybrid system—link level simulator. Moreover, the performance of a proposed technique that is based on the maximization of the desired signal of a Mobile Station (MS) to the total amount of interference caused to the rest of the network is evaluated as well. As results indicate, this technique can achieve up to 45 % transmission power gain for high data rate services compared to the case where only the maximization of the desired MS’s signal is considered.