abstract the extent to which teachers’ written corrective feedback (wcf) is conducive to esl learners’ improvement has been discussed since truscott’s claim in 1996. the mentioned debate continues because there has been lots of contrastive research studies with different results. this paper presents the results of a 2-month study of the effectiveness of wcf to 65 low intermediate iranian learne...

The adaptive zero-error capacity of discrete memoryless channels (DMC) with noiseless feedback has been shown to be positive whenever there exists at least one channel output “disprover”, i.e. a channel output that cannot be reached from at least one of the inputs. Furthermore, whenever there exists a disprover, the adaptive zero-error capacity attains the Shannon (small-error) capacity. Here, ...

This work presents a summary of a proposal for a feedback scheme in a multi-input-multi-output (MIMO) communication system based on a differential quantization strategy applied to the channel response. The performance of this scheme is evaluated using real data and channel measurements obtained with the Eurecom’s MIMOOpenAir Sounder (EMOS). More concretely, the impact of having a delay in the f...

Limited feedback is a paradigm for the feedback of channel state information in wireless systems. In multiple antenna wireless systems, limited feedback usually entails quantizing a source that lives on the Grassmann manifold. Most work on limited feedback beamforming considered single-shot quantization. In wireless systems, however, the channel is temporally correlated, which can be used to re...

This paper proposes a random access based feedback protocol for the clustered orthogonal frequency division multiplexing (OFDM) downlink, which allows users to feed back their channel information to the base station (BS) in a distributed fashion. The proposed protocol employs a contention channel that consists of fixed amount of system resource to carry the feedback for each cluster. Active use...

In this paper we obtain information theoretical conditions for tracking in linear time-invariant control systems. We consider the particular case where the closed loop contains a channel in the feedback loop. The mutual information rate between the feedback signal and the reference input signal is used to quantify information about the reference signal that is available for feedback. This mutua...

In Part I of this paper, we presented a scheme for effectively exploiting a noiseless feedback link associated with an additive white Gaussian noise channel with no signal bandwidth constraints. We now extend the scheme for this channel, which we shall call the wideband (WB) scheme, to a band-limited (BL) channel with signal bandwidth restricted to (W , W). Our feedback scheme achieves the well...

This paper describes the design of a backchannel feedback corpus and its evaluation, aiming at realizing in-car spoken dialogue systems with high responsiveness. We constructed our corpus by annotating the existing in-car spoken dialogue data with back-channel feedback timing information in an off-line environment. Our corpus can be practically used in developing dialogue systems which can prov...

We derive upper and lower bounds on the reliability function for the common-message discrete memoryless broadcast channel with variable-length feedback. We show that the bounds are tight when the broadcast channel is stochastically degraded. For the achievability part, we adapt Yamamoto and Itoh’s coding scheme by controlling the expectation of the maximum of a set of stopping times. For the co...

We analyze the sum-rate performance of a multi-antenna downlink system carrying more users than transmit antennas, with partial channel knowledge at the transmitter due to finite rate feedback. In order to exploit multiuser diversity, we show that the transmitter must have, in addition to directional information, information regarding the quality of each channel. Such information should reflect...