On Coding of Scheduling Information in OFDM

Abstract

Abstract-Control signaling strategies for scheduling information in cellular OFDM systems are studied. A single-cell multiuser system model is formulated that provides system capacity estimates accounting for the signaling overhead. Different scheduling granularities are considered, including the one used in the specifications for the 3G Long Term Evolution (LTE). A greedy scheduling method is assumed, where each resource is assigned to the user for which it can support the highest number of bits. The simulation results indicate that the cost of control signaling does not outweigh the scheduling gain, when compared with a simple round-robin scheme that does not need signaling of scheduling information. Furthermore, in the studied scenario, joint coding and signaling of scheduling information over all selected users is found to be superior to separate coding and signaling for each user. The results also indicate that the scheduling granularity used for LTE provides better performance than the full granularity.

Comparison of Strategies for Signaling of Scheduling Assignments in Wireless OFDMA

“…The paper extends our conference paper [1], in that we work with more realistic cost measures for the performance evaluation and for the error-correcting codes involved. Herein we also consider both proportional fair, round-robin and systemthroughput maximizing schedulers.…”

“…It is worth mentioning that, there is generally also a need for a few unused guard subcarriers which would additionally reduce the spectral efficiency. However we neglect this loss 1 We consider a noise-limited system throughout the paper. To include cochannel interference in the model, N 0 should be replaced with N 0 + I i,j , where I i,j denotes the interference power over resource element (i, j).…”

“…In order to find the required number of CCEs with the SCET scheme, we start with the first scheduled user and determine the number of CCEs needed for the transmission of N (1) map bits corresponding to the scheduling matrix U (1) . In order to distinguish between the users, we add a user-specific CRC to each user's data.…”

Differential Signaling of Scheduling Information in Wireless Multiple Access Systems

“…The idea therein is to use semi-persistent scheduling decisions and to change the scheduling assignments only if the gain in throughput is larger than the loss due to the signaling caused by transmission of the new assignments. In [5], two different ways for encoding and transmission of scheduling assignments were studied. The performance of the two schemes in terms of the overall system throughput was evaluated for different scheduling granularities and strategies.…”

Reducing Downlink Signaling Traffic in Wireless Systems Using Mobile-Assisted Scheduling

“…In [6], a method for scheduling under a constraint on the control signaling cost was proposed. In [7] two different schemes for encoding of the control information were considered and their performances in terms of system throughput were evaluated.…”