位相連続化QPSKを用いた大容量2Mビット/秒8Mチップ/秒携帯diffCDMAの提案とそのシステム容量

Abstract

From the frequency usage efficiency points of view, the novel CDMA with phase continuity QPSK is proposed in this paper to achieve such high reliability as shown in free space propagation, and is also discussed in system capability to get significant scheme for system design. Phase continuity is facilitated by substituting smoothing function over adjacent symbol fringes, in which the function touches current and next frame phase values with 0th order contact and varies with the steepest gradient just at the center. Simulations are verified to be error free to transmit 2 Mbps over 7.282 MHz bandwidth by employing diffCDMA with phase continuous QPSK without any compensations. The system configuration is also optimized through simulations to be defined by 11.651 MHz bandwidth, where the necessary Eb/No is -11.5 dB for error free in 2-rap Rayleigh fading environment of DUR=10 dB with 1 micro second delay over 2 GHz domain.