Comparison of time guard-band and coding strategies for OFDM digital cellular radio in multipath fading

This paper focuses on the combined use of convolutional coding and orthogonal frequency division multiplexing (OFDM) in a multipath channel. The use of time guard-intervals to reduce CCI and ICI is vital for good performance in such channels, but is wasteful of bandwidth. The paper examines the degradation in performance due to the use of sub-optimal time guard-intervals for uncoded and coded OFDM designs. In particular, a comparison is made between the use of low-rate orthogonal convolutional codes (LROCC) and conventional high-rate convolutional codes for different time guard-intervals. It is found that LROCC codes outperform high-rate convolutional codes, particularly when the time guard-interval period approaches its optimum value.