Throughput of Hybrid (DS-SFH) Spread-Spectrum Random-Access Communications.

Abstract

The multiple-access capability of hybrid direct-sequence slow frequency hopped (DS-SFH) spread-spectrum systems with forward- error control coding is investigated. Frequency-slot synchronous and asynchronous schemes, packet slotted schemes with several chips of the signature sequence employed in each bit (or symbol, if not binary) and varying hopping rates are considered and different data modulation schemes (BPSK, M-ary, FSK) with coherent or noncoherent demodulation are examined. The performance of forward-errorcontrol coding schemes, such as Reed- Solomon codes with errors-only and errors and erasures decoding, with or without side information about the presence or absence of multiple-access interference, is evaluated.