Devices configured with jointly aggregated TDD and FDD component carriers

A communication device for assigning transmission timing of Physical Uplink Control Channel (PUCCH) configured with jointly aggregated Time Division Duplex (TDD) and Frequency Division Duplex (FDD) component carriers, comprising:

• a processing means;
• and a storage unit, coupled to the processing means, for storing a program code, wherein the program code instructs the processing means to execute steps of:
• receiving a first downlink (DL) transmission on a first cell;
• determining a first uplink (UL) transmission timing of the first cell by associating a UL subframe on a second cell with at least one DL subframe on the first cell, wherein every DL subframe on the first cell is associated to one UL subframe on the second cell, and wherein the at least one DL subframe is k subframes prior to the UL subframe;
• and transmitting a corresponding feedback of the first DL transmission in the associated UL subframe on the second cell;
• wherein the first cell is on an FDD component carrier and the first cell has no PUCCH to transmit the corresponding feedback of the first DL transmission;
• and wherein the second cell is on a TDD component carrier and the second cell uses PUCCH to transmit the corresponding feedback of the first DL transmission of the first cell;
• wherein k falls between 4 and 6 when the second cell is configured with UL-DL Configuration 0, k falls between 4 and 7 when the second cell is configured with UL-DL Configuration 1, k falls between 4 and 8 when the second cell is configured with UL-DL Configuration 2, k falls between 4 and 11 when the second cell is configured with UL-DL Configuration 3, k falls between 4 and 12 when the second cell is configured with UL-DL Configuration 4, k falls between 4 and 13 when the second cell is configured with UL-DL Configuration 5, and k fails between 4 and 7 when the second cell is configured with UL-DL Configuration 6.

A communication device configured with jointly aggregated Time Division Duplex (TDD) and Frequency Division Duplex (FDD) component carriers, comprising:

• a processing means;
• and a storage unit, coupled to the processing means, for storing a program code, wherein the program code instructs the processing means to execute steps of:
• receiving a first downlink (DL) data from an first component carrier (CC);
• and setting a first round trip time (RTT) Timer to a period for reception of retransmission on the first CC when the communication device is configured with a first Physical Uplink Control Channel (PUCCH) on a second CC for transmitting an acknowledge (ACK) or a negative-acknowledge (NACK) feedback for the first DL data;
• when the first CC is an FDD CC and the second CC is a TDD CC, the period equals to 4+k subframes, wherein k is an interval between a DL transmission of the first DL data and a transmission of the ACK or NACK feedback for the first DL data;
• when the first CC is a TDD CC and the second CC is an FDD CC, the period equals to 8 subframes.