A Modified Orthogonal Sequence for Spread Spectrum Communication and Distance Estimation Multiplex System

In spread spectrum communication and distance estimation multiplex system, a unique compound sequence (inner sequence compound with outer sequence) enable the system to achieve the mission of double precision range and have capacity of high efficient communication. However, the improvement of the system performance increases the probability of inner sequence interfering with each other which results in declining anti-noise performance of the system; therefore we must select a pseudonoise (PN) random sequence with good correlation property as inner sequence for solving the above problem. In this paper, we propose a modified orthogonal sequence which is structured by compounding Walsh sequence with specific selected m sequence. The modified sequence has a similar or better correlation property compared with some other existed orthogonal sequences, especially in code balance and flexible construction method. From performance analysis and computer statistics, we can conclude that the new sequence has a good performance which is fit for the multiplex system