Signal decoding method using both signal and channel state information

DETAILED DESCRIPTION This need and others are substantially met through provision of the method of recovering an information signal modulated on a carrier signal and transmitted through a channel as disclosed herein.
Pursuant to this method, a receiver receives the carrier signal and demodulates it to provide a received information signal.
The receiver also processes the carrier signal to determine channel state information that corresponds temporally to the received information signal.
The received information signal and the channel state information are then both utilized in a decoding algorithm to recover the information signal.
In one embodiment, the decoding algorithm comprises a Viterbi Algorithm configured to implement a decoder for Trellis Coded Modulation.
In another embodiment, the channel state information corresponds to carrier amplitude information, such as received signal strength indication information.
In another embodiment, processing of the carrier signal to determine channel state information can include a variety of additional processing steps to further condition the channel state information prior to using that information with the estimated information signal in the decoding algorithm.
For example, the channel state information can first be normalized, thereby potentially minimizing subsequent computational requirements.
The channel state information can also be compensated to accommodate fixed delays that occur in the reception process with respect to determination of the received information signal.
The channel state information can further be subjected to morphological erosion to ensure conservative use of the channel state information in the decoding algorithm.
Also, this processing can include fixing the channel state information output to the decoder at a fixed value in response to detecting a predetermined channel condition, such as a lack of a faded carrier signal over at least a predetermined period of time.
The latter provision avoids that mischief which may occur in a non-fading communication channel when ordinary channel noise might otherwise be interpreted as useful channel state information