Cellular wireless systems rely on frame-based transmissions. The frame designis conventionally based on heuristics, consisting of a frame header and a datapart. The frame header contains control information that provides pointers tothe messages within the data part. In this paper, we revisit the principles offrame design and show the impact of the new design in scenarios that featureshort data packets which are central to various 5G and Internet of Thingsapplications. We treat framing for downlink transmission in an AWGN broadcastchannel with K users, where the sizes of the messages to the users are randomvariables. Using approximations from finite blocklength information theory, weestablish a framework in which a message to a given user is not necessarilyencoded as a single packet, but may be grouped with the messages to other usersand benefit from the improved efficiency of longer codes. This requires changesin the way control information is sent, and it requires that the users need tospend power decoding other messages, thereby increasing the average powerconsumption. We show that the common heuristic design is only one point on acurve that represents the trade-off between latency and power consumption.
展开▼
