A New Coding System for Improved Radio Transmission of Digital Signals

现有的数字无线电系统使用具有相干检测的连续相位频率调制，以频谱效率换取低误码率。在某些应用中，如卫星和移动无线电，由于衰落和多普勒频移，它们容易退化。这项研究将使用非相干、基于鉴别器的检测来研究CP-FM信号空间的网格编码的使用。该编码方案将被应用于对称和非对称信号星座。将研究在存在莱斯衰落多普勒效应的情况下的系统性能，并将其与诸如MSK、双二进制和TFM的标准调制方案的非相干检测进行比较。最后，将为给定码率选择最佳调制方案。成功的努力可以产生更高效的通信系统，在相同的误码率下需要更少的功率，减轻重量，更高的可靠性，提高频谱效率，更好的多普勒和衰落性能，以及更低的成本。

Existing digital radio systems, which use continuous phase frequency modulation with coherent detection, trade spectral efficiency for low bit error rate. In certain applications, such as satellite and mobile radio, they are subject to degradation due to fading and doppler shifts. This research will investigate the use of trellis coding of the signal space with CP-FM, using non-coherent, discriminator-based detection. This coding scheme will be applied for both symmetrical and asymmetrical signal constellations. System performance in the presence of Rician fading doppler effects will be investigated and compared to non-coherent detection of standard modulation schemes such as MSK, duo-binary, and TFM. Finally, an optimum modulation scheme will selected for a given code rate. A successful effort could result in more efficient communications systems that require less power for the same bit error rate, reduced weight, higher reliability, improved spectral efficiency, better doppler and fading performance, and lower costs.