Recently, various versions of combining code division multiple access (CDMA) with orthogonal frequency-division multiplexing (OFDM) have drawn much attention for IMT-Advanced (4G) and new broadcasting systems. In particular, variable-spreading-factor orthogonal frequency and code multiplexing (OFCDM) and multicarrier CDMA adopt 2-D spreading, i.e., time-domain and frequency-domain spreading. Maeda, Yang and Hanzo, Zheng, and Zhou have mentioned a few strong points of 2-D spreading. However, what is missing in their analysis/simulations is the system-level aspect of 2-D spreading. In particular, we are interested in the following questions: "What are the advantages of frequency-domain spreading in multicell environments?"and "What is the optimal frequency reuse factor in 2-D spreading systems?"Answers to these questions are investigated in this correspondence.
All Science Journal Classification (ASJC) codes
- Automotive Engineering
- Aerospace Engineering
- Electrical and Electronic Engineering
- Applied Mathematics