Sensitivity indicator for a radio receiver and method therefor

A method for providing a substantially continuous display of signal quality in a radio receiver operating in a communication system utilizing a predetermined signaling format which includes data and a periodically transmitted data sequence characteristic of the signaling format, said method comprising the steps of:

• A. receiving the transmitted data and the periodically transmitted data sequence;
• B. comparing the periodically transmitted data sequence received with a predetermined data sequence characteristic of the signaling format;
• C. generating correlation detection signals indicating the detection and absence of detection of correlation between the periodically transmitted data sequence received and the predetermined data sequence;
• D. generating a first correlation count indicating the detection of a first received data sequence and storing the same in response to the first correlation detection signal being generated which indicates the detection of correlation between the periodically transmitted data sequence received and the predetermined data sequence;
• E. starting a timer to provide a measurement of elapsed time when the first correlation count indicating the detection of a first received data sequence is generated;
• F. generating subsequent correlation counts indicating the detection and absence of detection of subsequently received data sequences and sequentially storing the same in response to subsequent correlation detection signals being generated which indicate the detection and absence of detection of correlation between the periodically transmitted data sequence received and the predetermined data sequence;
• G. resetting the timer each time a subsequent correlation count indicating the detection of a received data sequence is generated;
• H. detecting when a predetermined number of correlation counts have been stored following the storage of the first correlation count;
• and
• I. displaying an indication of the number of correlation counts stored which indicate detection of the received data sequences in response to a predetermined number of correlation detection signals being generated.

A selective call receiver comprising:

• means for receiving selective call signals transmitted in a predetermined signaling format, the signaling format including at least address information transmitted as a sequence of data, and a periodically transmitted data sequence characteristic of the signaling format;
• means, responsive to the received data sequence, for synchronizing the reception of the selective call signals in the predetermined signaling format;
• timing means responsive to said synchronizing means for providing timing signals synchronized to the reception of the periodically transmitted data sequence;
• means for storing a predetermined data sequence characteristic of the signaling format;
• means for comparing the data sequences received with the predetermined data sequence stored, and for generating a correlation detection signal indicating the detection and absence of detection of correlation between the received and stored data sequences;
• register means, having a predetermined number of storage locations, responsive to the correlation detection signal for accumulating a first correlation count indicating a detection of a first received data sequence characteristic of the signaling format, said register means further sequentially accumulating subsequent correlation counts indicating the detection and absence of detection of subsequently received data sequences;
• first counting means, for providing a measure of elapsed time by generating a count in response to the timing signals,
• controller means, coupled to said register means, for detecting when the first detected correlation count accumulated has shifted to the last storage location of said register means, and for generating a display enable signal in response thereto, said controller means further resetting the count of said first counting means in response to the correlation detection signal being generated;
• and
• display means, responsive to the display enable signal, for displaying an indication of the accumulated correlation count which corresponds to the number of correlations between the received and stored data sequences within a first time interval, the indication displayed thereafter being periodically updated with subsequently received data sequences characteristic of the signaling format to provide a substantially continuous display of the quality of selective call signal reception.