Methods, communications device and infrastructure equipment

1. A method of receiving data at a communications device from an infrastructure equipment forming part of a radio network part of a wireless communications network, the method comprising:

receiving at the communications device one or more downlink transport blocks transmitted in one or more time divided units of a wireless access interface, the wireless access interface comprising in a frequency dimension resource elements, each of the resource elements for carrying a sub-carrier of an Orthogonal Frequency Division Multiplexed, OFDM, symbol, the resource elements being formed in the frequency dimension into a plurality of physical resource blocks, and each of the one or more downlink transport blocks being transmitted within a narrow bandwidth comprising a plurality of the physical resource blocks; and

estimating the data carried by each of the one or more downlink transport blocks by performing an error correction decoding in accordance with the error correction encoding applied by the infrastructure equipment, wherein

each of the one or more downlink transport blocks is transmitted repeatedly a plurality of times in a corresponding plurality of the time divided units of the wireless access interface, and

the estimating the data carried by each of the downlink transport blocks comprises

generating, for each repeated transmission of the downlink transport block, for each of a plurality of encoded data symbols of the transport block, a soft decision value for decoding the downlink transport block in accordance with an error correction encoding applied by the infrastructure equipment to the transport block,

storing the soft decision values for each repeated transmission of the downlink transport block in a soft buffer for decoding,

combining the soft decision values of each of the encoded data symbols from each of the repeated transmissions of the downlink transport block from the soft buffer to form for each of the encoded data symbols a combined soft decision value, and

estimating the data carried by each of the downlink transport blocks from the combined soft decision values by performing the error correction decoding in accordance with the error correction encoding applied by the infrastructure equipment,

the combining the soft decision values includes

determining that the soft decision values for one or more of the repeated transmissions of the downlink transport blocks for one or more of the plurality of physical resource blocks of the narrow bandwidth transmission were estimated in the presence of a transmission to another communications device from the infrastructure equipment in the one or more physical resource blocks, and

excluding the determined soft decision values from the combined soft decision values for the corresponding encoded data symbols,

the method further comprises receiving an indication from the infrastructure equipment of the one or more of the plurality of physical resource blocks of the narrow bandwidth downlink transmission of each transport block which overlap with physical resource blocks in which the infrastructure equipment is also transmitting downlink signals to the other communications device, the soft decision values estimated in the presence of the transmission to the other communications device being determined from the indication received from the infrastructure equipment,

the soft buffer comprises a plurality of soft buffer portions in each of which a plurality of the soft decision values are stored, and

the communications device is configured to discard all of the soft decision values in each of the buffer portions which comprise one or more of the soft decision values for each transport block comprising the one or more physical resource blocks which overlap with physical resource blocks in which the infrastructure equipment is also transmitting downlink signals to the other communications device.

2. The method according to claim 1 , wherein the indication is received from the infrastructure equipment via downlink control information, DCI, carried by a physical downlink control channel.

3. The method according to claim 1 , wherein

the communications device is configured to discard from each of the buffer portions any of the soft decision values for each transport block comprising the one or more physical resource blocks which overlap with physical resource blocks in which the infrastructure equipment is also transmitting downlink signals to the other communications device.

4. The method according to claim 1 , wherein

the communications device is configured, when estimating the data carried by each of the one or more downlink transport blocks by performing an error correction decoding in accordance with the error correction encoding applied by the infrastructure equipment, to exclude each of the one or more of the plurality of physical resource blocks of the narrow bandwidth downlink transmission of each transport block which overlap with physical resource blocks in which the infrastructure equipment is also transmitting downlink signals to the other communications device.

5. The method according to claim 1 , wherein the determining the soft decision values estimated in the presence of the transmission to the other communications device comprises:

assuming that one or more of the repeated transmissions of the downlink transport block has been received in the presence of the transmission to the other communications device;

re-estimating the data carried by the downlink transport block by performing the error correction decoding on the combined soft decision values excluding those soft decision values generated from the assumed one or more repeated transmissions of the downlink transport block received in the presence of the transmission to the other communications device; and

determining that the estimation of the data carried by each of the downlink transport blocks from the combined soft decision values has been estimated correctly, and if not, assuming that a different one or more of the repeated transmissions of the downlink transport block has been received in the presence of the transmission to the other communications device and repeating the re-estimating.

6. The method according to claim 1 , wherein the receiving at the communications device the one or more downlink transport blocks comprises:

receiving the one or more downlink transport blocks for each of one or more automatic repeat request, ARQ, type transmissions from the infrastructure equipment.

7. The method according to claim 6 , further comprising:

determining, using the estimate of the data carried by the downlink transport block, whether to transmit a feedback message to the infrastructure equipment comprising an acknowledgment or a negative acknowledgement, or no feedback message in accordance with the ARQ-type protocol; and

if determined to transmit the feedback message, transmitting the determined feedback message, to the infrastructure equipment from the communications device.

8. The method according to claim 6 , further comprising:

receiving, via radio resource control, RRC, signalling from the wireless communications network, an indication of a number of soft buffer portions which may form the soft buffer; and

determining, based on the indicated number of soft buffer portions, a number of the soft buffer portions which the communications device is able to assign for each of the one or more ARQ type transmissions.

9. A communications device configured to receive data from an infrastructure equipment forming part of a radio network part of a wireless communications network, the communications device comprising:

transceiver circuitry and controller circuitry configured in combination to:

receive one or more downlink transport blocks transmitted in one or more time divided units of a wireless access interface, the wireless access interface comprising in a frequency dimension resource elements, each of the resource elements for carrying a sub-carrier of an Orthogonal Frequency Division Multiplexed, OFDM, symbol, the resource elements being formed in the frequency dimension into a plurality of physical resource blocks, and each of the one or more downlink transport blocks being transmitted within a narrow bandwidth comprising a plurality of the physical resource blocks; and

estimate the data carried by each of the one or more downlink transport blocks by performing an error correction decoding in accordance with the error correction encoding applied by the infrastructure equipment, wherein

each of the one or more downlink transport blocks is transmitted repeatedly a plurality of times in a corresponding plurality of the time divided units of the wireless access interface, and

to estimate the data carried by each of the downlink transport blocks, the transceiver circuitry and the controller circuitry are configured to

generate, for each repeated transmission of the downlink transport block, for each of a plurality of encoded data symbols of the transport block, a soft decision value for decoding the downlink transport block in accordance with an error correction encoding applied by the infrastructure equipment to the transport block,

store the soft decision values for each repeated transmission of the downlink transport block in a soft buffer for decoding,

combine the soft decision values of each of the encoded data symbols from each of the repeated transmissions of the downlink transport block from the soft buffer to form for each of the encoded data symbols a combined soft decision value, and

estimate the data carried by each of the downlink transport blocks from the combined soft decision values by performing the error correction decoding in accordance with the error correction encoding applied by the infrastructure equipment,

to combine the soft decision values, the controller circuitry and the transceiver circuitry are configured to

determine that the soft decision values for one or more of the repeated transmissions of the downlink transport blocks for one or more of the plurality of physical resource blocks of the narrow bandwidth transmission were estimated in the presence of a transmission to another communications device from the infrastructure equipment in the one or more physical resource blocks, and

exclude the determined soft decision values from the combined soft decision values for the corresponding encoded data symbols,

the controller circuitry and the transceiver circuitry are configured to receive an indication from the infrastructure equipment of the one or more of the plurality of physical resource blocks of the narrow bandwidth downlink transmission of each transport block which overlap with physical resource blocks in which the infrastructure equipment is also transmitting downlink signals to the other communications device, the soft decision values estimated in the presence of the transmission to the other communications device being determined from the indication received from the infrastructure equipment,

the soft buffer comprises a plurality of soft buffer portions in each of which a plurality of the soft decision values are stored, and

the controller circuitry and the transceiver circuitry are configured to discard all of the soft decision values in each of the buffer portions which comprise one or more of the soft decision values for each transport block comprising the one or more physical resource blocks which overlap with physical resource blocks in which the infrastructure equipment is also transmitting downlink signals to the other communications device.

10. An infrastructure equipment forming part of a radio network part of a wireless communications network configured to transmit data to a communications device, the infrastructure equipment comprising:

transceiver circuitry and controller circuitry configured in combination to:

transmit to the communications device one or more downlink transport blocks transmitted in one or more time divided units of a wireless access interface, the wireless access interface comprising in a frequency dimension resource elements, each of the resource elements for carrying a sub-carrier of an Orthogonal Frequency Division Multiplexed, OFDM, symbol, the resource elements being formed in the frequency dimension into a plurality of physical resource blocks, and each of the one or more downlink transport blocks being transmitted within a narrow bandwidth comprising a plurality of the physical resource blocks; and

transmit an indication to the communications device of the one or more of the plurality of physical resource blocks of the narrow bandwidth downlink transmission of each transport block which overlap with physical resource blocks in which the infrastructure equipment is also transmitting downlink signals to the other communications device, wherein

the communications device determines which of one or more soft decision values estimated by the communications device for the purposes of decoding the downlink transport blocks were estimated in the presence of the transmission to the other communications device based on the indication received from the infrastructure equipment,

the communications device receives an indication from the infrastructure equipment of the one or more of the plurality of physical resource blocks of the narrow bandwidth downlink transmission of each transport block which overlap with physical resource blocks in which the infrastructure equipment is also transmitting downlink signals to the other communications device, the soft decision values estimated in the presence of the transmission to the other communications device being determined from the indication received from the infrastructure equipment,

the soft buffer comprises a plurality of soft buffer portions in each of which a plurality of the soft decision values are stored, and

the communications device discards all of the soft decision values in each of the buffer portions which comprise one or more of the soft decision values for each transport block comprising the one or more physical resource blocks which overlap with physical resource blocks in which the infrastructure equipment is also transmitting downlink signals to the other communications device.