Research On Performance Of MBOK Multiple Access And Anti-Jamming

Spread spectrum communications has a good performance of anti-interference and keeping confidence which is good to meet the standard of modern communication system. However, the advantages are occupied by an exchange of large bandwidth. So it is restricted in the band limited environment. M-ary spread spectrum is a way to reduce the spectrum band, but it needs a much more complexity of device. M-ary bi-orthogonal keying, which is abbreviated as MBOK, is a new spread spectrum technology which combines the normal direct sequence spread spectrum and M-ary spread spectrum. MBOK has a good performance of anti-interference as DSSS, and it reduces the bandwidth. Thus, it can be used on the conditions that the bandwidth is limited and variable transmission rate is needed. The concept of MBOK is first brought in the 60th, 20th century. However, as the complexity of communication equipment is developing, MBOK is broadly used for the last several years.This paper researches mainly on the performance of MBOK based on the simulation with Matlab. First, this paper introduces the basic concept of M-ary spread spectrum system and its error probability of union boundary. Then it introduces the mathematical model and basic principles of MBOK. After giving out the spreading and de-spreading principle, it introduces the main design scheme of the system. In regard to single-user, it researches the performance of bit error rate and processing gain under AWGN of MBOK. And it analyzes the performance of anti wideband interference and anti single-tone interference. In regard to multi-users, multi-user capacity is studied in different situations comparing with the traditional DSSS under AWGN and Rayleigh channel.