A Study on the generation and characteristics of Bent codes for Code Division Multiple Access Communication System

부호분할 다중통신 시스템을 위한 Bent 부호발생 및 특성에 관한 연구

In this paper we consider the design of bent sequence generators employing a modified bent function. Through the experimental results and simulation, we show that the period of sequences is $2^n$-1, the number of sequences in the set is $2n/2$, the largest magnitude of correlation is $2n/2$+1, and the sequence generators easy to randomly initialize into any assigned code and hence can be rapidly hopped from sequence to sequence. And we construct a code synchronization system with bent sequence generator as the local code generator, a sliding correlator and DLL as the acquisition subsystem and the tracking subsystem, respectively for DS-CODA, and verify the experimenta results for accomplishing code synchronism.

本文에서는 變形된 bent函數를 利用하여 bent 器를 構成하였으며 實驗과 시뮬레이숀을 通하여 發生된 bent 系列은 週期 $2^n$-1, 最大相關函數 $2n/2$+1과 最大符號群을 $2n/2$個를 갖으며 要求하는 系列로 쉽게 初期化될 수 있어 한 符號에서 다른 符號로의 變換이 빠르게 이루어질 수 있음을 보였다. 그리고 DS-CDMA를 위한 同期시스템을 bent 符號發生器를 국부 符號發生器로 利用하고 sliding相關器와 DLL 方式을 각각 初期同期 시스템과 追跡同期 시스템으로 構成하였으며 符號同期에 對한 動作特性을 확인하였다.