Consideration on system capability characteristics of portable 2 Mbps/8 Mcps CDMA with phase continuous QPSK

From the frequency usage efficiency points of view, a novel CDMA with phase continuity QPSK is proposed to achieve such high reliability as shown in free space propagation, and the capability characteristics are examined as a significant scheme for system design. Phase continuity is facilitated by substituting a smoothing function over adjacent frame fringes, in which the function touches the 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 for 2 Mbps transmission over a 7.282 MHz bandwidth by employing defCDMA with phase continuous QPSK without any compensation. The system configuration is also optimized through simulations to be defined by an 11.651 MHz bandwidth, where the necessary Eb/No is -11.5 dB for error free transmission in a 2-ray Rayleigh fading environment of DUR=10 dB with 1 micro second delay over a 2 GHz domain.