Some insights into the book:
Figure 4.5 presents the overall result of the improvement. The secondary side lobes of the KKF and asynchronous AKF are zero compared to the best of applied conventional code sequences such as Gold and Walsh sequences.
Through this innovation the spread signal can be best differentiated from noise and it can be filtered out in an optimum manner from interfering signals or co-channel interferences.
So the proposed perfect spread spectrum method using super-orthogonality solves many of the shortcomings of conventional CDMA and LTE technology (described in sections 3.1-3.6 in the book) and thus leads to the following advantages:
- Enhanced processing gain for detection in noisy environment while also giving higher bandwidth possibilities through multi-code modulation
- Higher data rates when using parallel coded transmission, in particular orthogonal M-ary CDMA coding and bundled parallel data transmission
- Lower power level required and less accurate power control loop
- Decreasing the transmitter power extends the battery reload period of mobile phones
- Lower power reduces health risks of electromagnetic radiation
- Latency periods and interruption reduced
- More subscribers per antenna through maximum code set
- Excellent reliability of transmission and substantially reduced bit error rate
- Optimized chip error tolerance
- Anti-jamming capability and stability against interfering signals
- Multiple-access-interference-free CDMA, perfect separation
- Multipath-interference-free CDMA, RAKE receiver not necessary
- Inherent frequency diversity aspect and OVSF capability
- Overlay with existing radio systems is possible
- Phased array antennas can be super-orthogonal coded for maximum antenna gain in the uplink.
The novel perfect spread spectrum method with super-orthogonal coding (or more precisely despreading) does only need simple additions, shift operations and multiplications in integer format for the binary AKF and KKF matched filters. Since all operations to achieve the super-orthogonality are handled on the receiver side the novel method can be completely integrated into the software-DSP (digital signal processor) for signal processing in the mobile receiver terminal (downlink). So those current mobile radio systems using Walsh sequences or OVSF sequences - among others HSPA, CDMA2000 and UMTS - do not even have to change the system standard. Also base station transceivers do not need severe hardware upgrades besides new software in DSPs since Walsh sequences or OVSF sequences are already applied in the standards. With the novel super-orthogonality method even the uplink direction is now feasible in asynchronous mode when mobile units start communication.
For satellite navigation the NAV signal could be improved with this new coding method. Here the SATNAV operator would have to introduce such signals. The receivers then have to be deployed with a firmware update for these new signals. This would not imply much technical effort for the future multi-standard receivers for SATNAV (GPS, Galileo, Glonass, Beidou etc.). The necessary long spreading codes are also possible.