Methods, infrastructure equipment and communications device

A method of transmitting data by an infrastructure equipment to a wireless communications device, the method comprising:

• establishing a connection between the infrastructure equipment and the wireless communications device,
• transmitting data to the wireless communications device according to a first transmission scheme,
• receiving from the wireless communications device a value of an index selected from a plurality of index values, each of the index values representing a range of values of a characteristic for which communications parameters of a transmitter in the infrastructure equipment and a receiver in the communication device should have to achieve an acceptable communications performance for a value of the characteristic within the range of values of the characteristic,
• selecting a second transmission scheme for the transmission of the data to the wireless communications device, based on the received value of the index received from one of the plurality of index values, the second transmission scheme having communications parameters according to the received value of the index and the communications parameters of the transmitter and the receiver which will satisfy the acceptable communications performance over a range of values of the characteristic including the measured value of the characteristic, and
• transmitting the data to the wireless communications device in accordance with the second transmission scheme, wherein a separation between the range of values of the characteristic for communications parameters achieving an acceptable performance corresponding to at least two of the plurality of indexes is not equal to a separation between the range of values of the characteristic for communications parameters achieving an acceptable performance corresponding to two others of the plurality of indexes.

A communications device configured to transmit radio signals to and/or receive radio signals from an infrastructure equipment of a wireless communications network, the communications device comprising

• a receiver circuit configured to receive radio signals transmitted by the infrastructure equipment via a wireless access interface,
• a transmitter circuit configured to transmit radio signals to the infrastructure equipment via the wireless access interface, and
• a controller circuit configured to control the transmitter circuit and the receiver circuit to transmit data to or receive data from the wireless communications network via the infrastructure equipment, wherein the controller circuit is configured to control the receiver circuit
• to receive signals transmitted by the infrastructure equipment,
• to measure a characteristic associated with the received signals,
• to select an index value from one of a plurality of index values, each of the index values representing a range of values of the characteristic for which communications parameters of a transmitter in the infrastructure equipment and a receiver in the communication device should have to achieve an acceptable communications performance for values of the characteristic within the range of values of the characteristic, the selected index value representing the communications parameters of the transmitter and the receiver which will satisfy the acceptable communications performance over a range of values of the characteristic including the measured value of the characteristic, and
• the controller circuit is configured to control the transmitter circuit, subject to the selected index value, to transmit the selected index value to the infrastructure equipment, wherein, a separation between the range of values of the characteristic for communications parameters achieving an acceptable performance corresponding to at least two of the plurality of indexes is not equal to a separation between the range of values of the characteristic for communications parameters achieving an acceptable performance corresponding to two others of the plurality of indexes.