Collision Problem Avoidance in Packet Acquisition for Frequency Hopped Random Multiple Access

Abstract

Random multiple access (RMA) comprises a large class of multiple access protocols, such as ALOHA. A common characteristic of all RMA protocols is that when a user transmits a data packet other users waiting until the transmission finished, so RMA can achieve very low latency and limit the network performance. In this paper a new technique that uses time and frequency hopping is proposed to solve the collision problem in packet acquisition of frequency hopped systems operating in random multiple access (RMA) environments. Moreover, the proposed scheme also improves the system performance due to the idea of dividing the time and frequency between all users in the system. Each user has a PN code pattern for any transmitted sync pulse that is responsible for selecting the frequency channel that carry the pulse and selects the time slot that the pulse uses it. We have presented an analytical approach for the proposed scheme to determine the packet acquisition performance in a RMA environment. To illustrate the accuracy of the analytical results, simulations are performed over a wide range of parameters such as the pulse length, pulse duty cycle, number of synchronization pulses and the number of users in the system.