Contention window adjustment method and apparatus and communication system

A contention window adjustment apparatus, comprising:

• a transmitter configured to transmit first data on a carrier, the carrier comprising two or more bandwidth units;
• and
• processor circuitry configured to adjust a contention window (CW) associated with a bandwidth unit within which at least parts of frequency-domain resources used for transmitting the first data are included according to hybrid automatic repeat request acknowledgement (HARQ-ACK) information of the first data,
• wherein the number of the bandwidth unit within which at least parts of frequency-domain resources used for transmitting the first data is at least one, and
• wherein the processor circuitry is configured to:
• according to a reception situation of a part of data of the first data, adjust a contention window associated with a bandwidth unit within which at least parts of frequency-domain resources used for transmitting the part of data are included.

A contention window adjustment apparatus, comprising:

• a transmitter configured to transmit first data on a carrier, the carrier comprising two or more bandwidth units;
• and
• processor circuitry configured to adjust a contention window (CW) associated with a bandwidth unit within which at least parts of frequency-domain resources used for transmitting the first data are included according to hybrid automatic repeat request acknowledgement (HARQ-ACK) information of the first data,
• wherein the number of the bandwidth unit within which at least parts of frequency-domain resources used for transmitting the first data is at least one, and
• wherein the processor circuitry is configured to:
• according to a reception situation of the first data, adjust a contention window associated with a bandwidth unit within which at least parts of frequency-domain resources used for transmitting a part of data of the first data are included.