Method and apparatus for providing power conservation in a communication system

In a communication system having a control system which generates code words, each code word having message information and redundant information, the communication system having at least one communication device having a decoder which uses a predetermined algorithm for decoding the code words, a method for recovering the message information from the code words comprising the steps of:

• receiving at the communication device the code words;
• determining the signal quality of the received code words;
• comparing the signal quality of the received code words to a predetermined value;
• decoding the entire received code words using the predetermined algorithim in order to decode the entire message information contained within the code words if the signal quality is below the predetermined value;
• and
• modifying the predetermined algorithm used by the decoder in order for the decoder to decode only that portion of the received code words when the signal quality of the received information signals is at least equal to the predetermined value which will allow the decoder to recover the entire message information contained in the code words.

A portable radio for use in a trunked communication system having a control system which generates convolutional coded signaling words, each convolutional coded signaling word having message information and redundant information, comprising:

• a receiver for receiving the convolutional coded signaling words;
• a means for determining the signal quality of the received convolutional coded signaling words;
• a decoder which uses a predetermined algorithm for decoding the received convolutional coded signaling words, the predetermined algorithm decodes the entire received convolutional coded signaling words in order to decode the entire message information contained within the received convolutional coded signaling words if the signal quality of the received convolutional coded signaling words is less than a predetermined value;
• and
• a control means for comparing the signal quality of the received convolutional coded signaling words with the predetermined value and for actuating the decoder in order to modify the predetermined algorithm in order for the decoder to decode only that portion of the received convolutional coded signaling words which will recover the entire message information contained within the convolutional coded signaling words when the signal quality of the received information signals is at least equal to the predetermined value.

A communication device for use in a communication system having cyclic nonsynchronous information signals, comprising:

• a receiver for receiving the cyclic nonsynchronous information signals;
• a means for determining the signal quality of the received cyclic nonsynchronous information signals;
• a decoder for decoding the cyclic nonsynchronous information signals;
• and
• a control means for comparing the signal quality of the received cyclic nonsynchronous information signals with a predetermined value and for actuating the decoder in order to decode only a portion of the received cyclic nonsynchronous information signals when the signal quality of the received cyclic nonsynchronous information signals is at least equal to the predetermined value, the control means follows a parity generation sequence in order to convert the portion of the received cyclic nonsynchronous information signal into a coded squelch word.

A communication device for use in a communication system having cyclic nonsynchronous information signals, comprising:

• a receiver for receiving the cyclic nonsynchronous information signals;
• a means for determining the signal quality of the received cyclic nonsynchronous information signals;
• a decoder for decoding the cyclic nonsynchronous information signals;
• and
• a control means for comparing the signal quality of the received cyclic nonsynchronous information signals with a predetermined value and for actuating the decoder in order to decode only a portion of the received cyclic nonsynchronous information signals when the signal quality of the received cyclic nonsynchronous information signals is at least equal to the predetermined value;
• and the control means follows a parity generation sequence having the sequence of:
• g(x)=x.sup.10 .sym.x.sup.7 .sym.x.sup.4 .sym.x.sup.3 .sym.x.sup.2 .sym.x.sym.1
• in order to convert the portion of the received cyclic nonsynchronous information signal into a coded squelch word.