The Research Of Multi-User Detection Technology Based On Direce Sequence Spread Spectrum Radio

Spread spectrum is a kind of communication technology, it uses broadening spectrum technology to achieve the information encryption and multi-access communications. Spread spectrum technology extends the signal to a very wide frequency band before sent out, so the radio frequency bandwidth is wider than the original signal bandwidth. spread spectrum communication has perfect performance on anti-interference anti-fading aspects, and it also has high efficiency on multi-access communication. Spread spectrum technology is widely used in military communication, space exploration and other military field, as in civil communication areas it also widely used.The purpose of this project is to develop multi-user spread spectrum radio, which contains more than one transmitter and a receiver. This paper gives the development of multi-user detection technology and analysis the performance of various algorithms. Considering the implementation process, it chooses interference cancellation algorithm for its low complexity. It realizes spread spectrum communication between multiple users and a base station on relevant software and hardware platform. Paper gives the Matlab simulation of nonlinear interface cancellation algorithm and improved the algorithm, making it easier to implement, reducing the hardware resource occupied. We extended hardware platform resource to meet the need of multiple users simultaneously receive. Paper uses a new method for carrier synchronous demodulation and according to the number of users it selects different spreading options. According to the simulation results the above design options achieved system design requirements.On this basis, this paper puts forward a series of optimized design scheme to improve system performance in the future research.