2021-09-062021-09-062001-12Ertaş, T. (2001). "Upper bounds on the free distance for a class of convolutional coded CPFSK signals". IEEE Communications Letters, 5(12), 483-485.https://ieeexplore.ieee.org/document/9744931089-7798https://doi.org/10.1109/4234.974493http://hdl.handle.net/11452/21688In this letter, we construct new encoder-independent upper bounds on the free distance for the rate (n - 1)/n convolutional encoders that are formed by using rate 1/2 encoders and combined with 2 n-level constant-envelope full-response CPFSK signals of single-h, by generalizing the bounding technique employed for the existing bounds. The new bounds coincide with the existing bounds for h ≤ 0.25, but are generally better for h > 0.25. We also present actual encoder combinations achieving the constructed new bounds with short constraint lengths.eninfo:eu-repo/semantics/closedAccessCoding errorsContinuous phase modulationEncoding (symbols)Free distanceUpper boundsConvolutional codesFrequency shift keyingPhase modulationSignal to noise ratioConvolutional codingCPFSKModulationDesignArticle0001730681000072-s2.0-0035703563483485512TelecommunicationsPhase Modulation; Bit Error Rate; Keying