Improved reliability and reduced packet loss for 4G wireless communication system

This paper address the problem related to discontinues-transmission (DTX), acknowledgement (ACK), negative- acknowledgement (NACK) detection in 4G wireless communication standards such as LTE/LTE-A. Typically, power estimate of a soft-demapper output is compared with a predefined threshold value to decode an ACK or NACK at the receiver. In some scenarios when received Downlink control channel (PDCCH) signal is not decoded by a user equipment (UE), UE fails to decode the corresponding physical channel. Hence in such situation, at enhanced-node base-station (eNB), in physical channel processing a DTX should be decoded instead of ACK/NACK. If threshold is not tuned properly, it will result in a wrong decoding of DTX as ACK or NACK. If a NACK is decoded, Downlink sends the previous packet to the UE hence should not cause an issue other than throughput degradation. But if an ACK is decoded, eNB sends a new packet and hence a loss of packet is obtained at UE-end which degrades the link performance and stability. This paper explains the method to tune the threshold value for an optimum performance.