仮想セグメントインターリービングの高速陸上移動通信システムへの適用と低チップレートdiffCDMAのマルチレイレイレーフェーディング伝送特性

Abstract

As well known, CDMA possesses such advantages as high capacity, low power transmission, and system flexibility, but it is contradictory suffered from broadband occupancy of wasting finite frequency resource owing to innocent spectrum spreading. Narrowing frequency bandwidth occupied over propagation channels is eager to efficiently develop the high capacity digital transmission as one of the most important key technologies promising effective frequency usage. Narrowing frequency bandwidth both of the primary and secondary modulations has been keenly discussed in these years to realize high capacity and speed diffCDMA The phase continuity. primary DQPSK, which has already reported in VTC98 as the first solution for 2 Mbps/ 8 Mbps diffCDMA, is retrieved here to realize the higher reliability and frequency efficiency 2 Mbps/ 4 Mbps diffCDMA Virtual segment interleaving is successfully discussed in this paper to reduce chip rating as one of the important solutions for effective frequency usage without introducing any problem in system reliability and complexity. Both continuous phase primary modulation and continuous chip shaping are also enhanced in this proposing 2Mbps/ 4Mcps diffCDMA.