High-speed data transmission with multicode modulation and turbo-codes for wireless personal communications

To provide universal personal communications, the next-generation PCNs will need to support a wide range of services requiring high bit rates. Transmitting high-speed data over wireless channels, however, is a difficult task. Recently, a new technique, known as multicode modulation, has been proposed to transmit high-speed data over wireless links. In this method, the high-rate information bits are serial-to-parallel converted to low-rate bit streams. Then the low-rate bits are modulated by direct sequence spread spectrum on a single carrier. The objective of this paper is to propose a low-complexity receiver structure for multicode modulation which uses fast Walsh transform (FWT). In addition, we will demonstrate that the use of coding in multicode modulation can significantly improve the system performance. Sample numerical results which illustrate the potential of multicode modulation with turbo-codes and convolutional codes over multipath Rayleigh fading channels will also be presented.