Performance Analysis of a Link-16/JTIDS Compatible Waveform With Noncoherent Detection, Diversity and Side Information
Abstract
The Joint Tactical Information Distribution System (JTIDS) is a hybrid frequency-hopped, direct sequence spread spectrum system. A (31, 15) Reed-Solomon (RS) code is used for forward error correction coding, and cyclical code-shift keying (CCSK) M-ary modulation is used, where each encoded symbol represents five bits. In this thesis, a compatible waveform consistent with the existing JTIDS channel waveform is analyzed. The system considered uses the same (31, 15) RS encoding as JTIDS. The coded symbols are then transmitted on the in-phase (I) and quadrature (Q) components of the carrier using 32-ary orthogonal signaling with 32-chip baseband waveforms and detected noncoherently. For noncoherent detection, only one five bit symbol is transmitted on both the I and Q components of the carrier, so the data throughput for noncoherent detection is half that of coherent detection. This alternative waveform is consistent with the direct sequence waveform generated by JTIDS. A sequential diversity of two, consistent with the double-pulse structure of JTIDS, is also assumed, and performance is examined both for the case of linear, soft diversity combining and also for soft diversity combining with side information. The type of side information considered is perfect side information (PSI). Based on the analysis, we conclude that the double-pulse structure outperforms the single-pulse structure for the alternative JTIDS waveform under examination. Moreover, pulsed-noise interference (PNI) degrades the performance of the receiver, but the use of PSI reduces the effect of PNI.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 2009
- Accession Number
- ADA509063
Entities
People
- Ioannis Kagioglidis
Organizations
- Naval Postgraduate School