Multi-format signaling for improved throughput rate transmission

In a typical digital communication system a single format such as non-return-to-zero (NRZ) is used, followed by modulation. The choice of modulation is made to conserve bandwidth so that the available bandwidth that is limited is efficiently used. Gaussian minimum shift keying (GMSK) is one such bandwidth-efficient modulation scheme. In this paper we consider a new and novel approach of improving the bandwidth efficiency by using multiple formatting instead of using a single format, such as NRZ alone in a code division multiple access (CDMA) system. The improvement in throughput expected is over 35%, and this improvement will enhance the bandwidth efficiency that can be achieved through the use of bandwidth-efficient modulation. There is a modest increase in the hardware in terms of generating and processing the multi-format signals, but the benefit from the bandwidth saved is expected to exceed the cost paid in terms of increased hardware complexity. There is no penalty in terms of increased power to achieve this bandwidth-efficiency improvement. Digital computer simulation of the proposed concept has validated the viability of the scheme to improve the throughput rate in a given bandwidth. In this paper a detailed description of the proposed multi-format signaling scheme is given, followed by some sample simulation results