| 摘要 |
Binary and Quadrature Feher's (F).-Modulation/Transmitter-Receiver (Transceiver) with reduced envelope fluctuations and peak radiation, increased efficiency delivered by baseband, intermediate frequency (IF) connected RF (radio frequency), Infrared (IR) and other devices. A subclass of these systems has a constant envelope. Power advantages, robust BER performance and linearly or nonlinearly amplified narrow spectrum without the pitfalls of conventional BPSK, DBPSK QPSK and pi/4 QPSK is attained. Feher's FBPSK improved efficiency transmitter is compatible with conventional BPSK receivers. FBPSK modems are based on using quadrature structure where Q channel data is inserted in quadrature with I channel data for certain applications. The Q channel data is "offset" from the changed data by an amount selectable between zero (0) and a specified time. Further improvement in the spectrum is attained using correlation between I and Q channels. FBPSK modem is shown to meet the IEEE 802.11 specified spectral direct sequence spread spectrum mask (-30 dB point) for wireless LAN, and leads output power gain of 6.5 dB over BPSK modems. The Crosscoupled Quadrature Structure is also suitable continuous mode and for burst operated TDMA, FDMA, CDMA, WCDMA and CSMA Frequency Modulation Quadrature AM (QAM), pi/4-shifted QPSK modems/processors are also disclosed. Reduced modulation index Gaussian FSK (GFSK), multilevel FM and crosscoupled Quadrature Amplitude Modulated (QAM) transmitters and combinations of these modulations and corresponding coherent demodulators are disclosed. Controlled rise and fall time descriptions of burst operated systems are included.
|
