Abstract
In this paper, we develop selective retransmission schemes for multiple-channel systems. The proposed schemes are selective automatic repeat request with fixed bandwidth, selective chase combining with fixed bandwidth, limited selective chase combining with fixed bandwidth and selective automatic repeat request with variable bandwidth. The main objective of the proposed schemes is to use the available power and bandwidth budget effectively along with selective retransmission to deliver the required data successfully within a limited number of transmissions. To investigate the performance of each scheme, we first analyze and derive closed-form expressions for the average spectral efficiency (SE), energy efficiency (EE) and delay for each scheme. Then, we compare the EE, SE and delay performance of each scheme versus different system parameters through numerical results.