A High Performance, Low Complexity, and Bandwidth Efficient Receiver

The available usable frequency spectrum is fixed but the demand for military communications is expected to grow exponentially over the next 20 years. One way to alleviate this problem is to utilize bandwidth efficient modulation and coding schemes such as Continuous Phase Modulation (CPM). Here Intelligent Automation, Inc. proposes a high performance, low complexity, and bandwidth efficient receiver for CPM signals. First, we use a high performance non-coherent receiver structure that has low complexity, does not require synchronization and reference carrier signals, and robust to various channel conditions such as fading, interference, and noise. The receiver combines soft decision differential phase detection and Viterbi decoding in a unified fashion. Early application of the proposed scheme has achieved excellent performance for Gaussian, satellite mobile and land mobile channels. Second, in order to achieve bandwidth efficiency, we propose to use CPM with efficient and low complexity coding schemes such as trellis codes. Our extensive past experience in modulation and coding will help select the best parameters in the signaling scheme in order to meet the 5bps/Hz requirement. Third, to address the low transmitter power issue, we have paid significant attention to both the signaling scheme and the receiver.