Analysis on the Feasibility and Application of GPS One-Way Communication Capability

The GPS system is capable of one-way communication (OWC) if the reserved bits of navigation message are utilized. Excluding the potential communication protocol overheads, a single frequency with one satellite transmits data at 0.5B/s; with the dual frequency transmission by using L1C and L2C frequencies, the parallel transmission of multiple satellites and the data compression, the transmission rate can be increased to 8B/s. The one-way communication of GPS is covert due to the covertness of communication channels, the occasionality of one-way communication and the disorderly distribution of information. The encryption techniques can make it difficult to discriminate communication events and decrypt communication content. The GPS one-way communication has the advantages of global coverage, day-and-night and all-weather operation, as well as low cost, thus it can meet the needs for special purposes, such as civilian emergency broadcast communication, military submarine command system and command of intelligence collection.