A channel hopping technique I: theoretical studies on band efficiency and capacity

The paper is motivated by the wish to increase the band efficiency of a mobile system using only one antenna at the receiver. The method proposed is based on the fact that the different channels can be effectively characterized by a CDMA receiver. Therefore, when we are hopping the signal transmission over different channels, this hopping information, i.e. the way of hopping, can be identified by the receiver. In the proposed system, the independent channels are used for signal mapping in such a way that transmission of an information symbol over a specified channel represents a specified channel bit value. The total bits of a symbol are the summation of the bits of the symbol itself and the channel bits. The theoretical analysis shows that the capacity gain of the channel hopping technique is the same as that of transmit diversity over the "flat" channel. However, for a DS-CDMA system under the assumption that the multiuser interference obeys a Gaussian distribution, the proposed system has larger system capacity.