Bit-level composite signal design for simultaneous ranging and communication

As the complexity of space exploration missions augments, how to enhance the overall performance of communication, ranging or other functions has become a challengeable problem. Considering the integration of communication and ranging, we present a bit-level composite signal for simultaneous ranging and communication. In this composite method, through a specially designed mapping scheme using low-weight codewords, the information sequence is converted to a sparse sequence which is then superimposed on the ranging code. For ranging, the correlation characteristics of the ranging code component can be maintained to calculate the transmitter-receiver distance. For communications, the sparse sequence can be extracted without interference by eliminating the ranging code component. Simulation results show that the proposed composite signal can support communication and ranging simultaneously with limited sacrifice of ranging performance, and the performance loss of ranging can be controlled and minimized by lowering the density of information sequences using different sparsification encoding methods.