On the design of a modern broadband physical layer for teleoperations links

Teleoperations (or teleops) is critical to current military tactical needs and so there is an urgent need for enabling technologies and quick deployment. In this context, we present a proof-of-concept physical layer design that represents a solution to the communication needs of the teleops mission. The key enabling capabilities of the physical layer design are as follows: (i) broadband throughputs above 6 Mbps, (ii) robustness to dynamic airborne channels and terrestrial multipath channels, and (iii) discontinuous spectra with carrier bandwidth flexibility (enabling operation even where contiguous bandwidth is unavailable). The physical layer design can also be deployed quickly as a retrofit of existing physical layers. It can be configured to be compatible with upper layers of existing JTRS waveforms - eliminating the need for costly changes at the MAC and networking layers. The physical layer design achieves all of this by combining multi-carrier continuous phase modulation (CPM) with advanced low density parity check (LDPC) forward error correction (FEC) coding. The bandwidths and locations of the carriers are variable, and this enables discontinuous spectra and bandwidth flexibility. For example, we can have one carrier 1.2 MHz wide or 12 carriers each 100 kHz wide moving identical payloads. Robustness to multi-path and dynamics is achieved by utilizing per-survivor processing (PSP) and adaptive iterative detection (AID). The physical layer design expands upon the positive qualities of FFT based OFDM systems. The physical layer design has been tested in simulation and lab testing. Testing confirms robust operation with many different bandwidth and carrier configurations. Lab testing in extreme dynamics (up to Mach 3) under ground urban multipath conditions confirms the design´s robustness.