Packet-Error Probability Analysis for Unslotted FH-CDMA (Frequency Hopped-Code-Division Multiple-Access) Systems with Error Control Coding

摘要

In unslotted frequency-hopped (FH) code-division multiple-access (CDMA) systems, a number of users can simultaneously transmit their packets by using quasi-orthogonal FH patterns (codes). The number of interfering users varies throughout the packet duration; thus, the symbol error probability is not constant throughout the transmission, and symbol errors with the packet are not independent. In this report we present an exact analysis of such systems that use Reed-Solomon error-control coding. The computational task for the evaluation of the performance is enormous; thus, bounds and approximations are derived that are easier to compute and that prove to be very close to the exact results for the cases in which the exact results are computable. The results of this study confirm our observation, made also elsewhere, that the widely used threshold-based model of other-user interference is not an accurate one. (RH)