Interference mitigation in a device supporting multiple radio technologies communicating in overlapping time periods
A wireless terminal that supports operation on a first wireless technology and operation on a second wireless technology performs a first set of measurements on a received signal on first operating frequency of the first wireless technology, wherein the first set of measurements are performed during time periods that overlap time periods during which the wireless terminal transmits signals of the second wireless technology. The terminal also performs interference avoidance to avoid interference from transmissions of signals of the second wireless technology to reception of signals of the first wireless technology if the first set of measurements indicates interference due to transmission of signals of the second wireless technology by the wireless terminal.
1. A method in a wireless terminal supporting operation on a first wireless technology and a second wireless technology, the method comprising:
determining, by the wireless terminal, a threshold of a received signal level of a first base station of a first wireless technology,
wherein the wireless terminal is unable to decode signals of the first base station that overlap transmission of signals of a second wireless technology by the wireless terminal when the received signal level of the first base station is below the threshold; and
performing interference avoidance to avoid interference from transmissions of signals of the second wireless technology by the wireless terminal to reception of signals from the first base station by the wireless terminal when the signal level of the first base station is below the threshold, comprising performing a handover from the first base station of the first wireless technology to a second base station of the first wireless technology operating on a second frequency distinct from the operating frequency of the first base station; and
indicating, by the wireless terminal, the threshold to the first base station,
wherein indicating the threshold to the first base station further includes indicating the threshold only when a transceiver of the second wireless technology in the wireless terminal is active.
2. The method of claim 1 further comprising:
performing a first set of measurements on a received signal on first operating frequency of the first wireless technology,
wherein the first set of measurements are performed during time periods that overlap time periods during which the wireless terminal transmits signals of the second wireless technology;
performing a second set of measurements on a received signal on first operating frequency of the first wireless technology,
wherein the second set of measurements are performed during time periods that do not overlap time periods during which the wireless terminal transmits signals of the second wireless technology;
comparing the first set of measurements with the second set of measurements; and
based on the comparison, sending, by the wireless terminal, an indication of a periodicity of a planned transmission by the wireless terminal where interference may occur.
3. The method according to claim 1 further comprising transmitting one or more measurement reports comprising one or more measurements, the one or more measurement reports including an indication that the measurements were performed during time periods that overlapped time periods during which the wireless terminal transmitted signals of the second wireless technology.
4. The method according to claim 1 , wherein the wireless terminal is configured to operate as a Wi-Fi access point and wherein the wireless terminal indicates to the first base station that a planned Wi-Fi transmission is expected to occur at a particular time.
5. The method of claim 1 further comprising:
performing a first set of measurements on a received signal on first operating frequency of the first wireless technology,
wherein the first set of measurements are performed during time periods that overlap time periods during which the wireless terminal transmits signals of the second wireless technology;
performing a second set of measurements on a received signal on first operating frequency of the first wireless technology,
wherein the second set of measurements are performed during time periods that do not overlap time periods during which the wireless terminal transmits signals of the second wireless technology;
comparing the first set of measurements and the second set of measurements with a threshold; and
based on the comparison, sending, by the wireless terminal, a measurement report when any set of measurements is greater than the threshold.
6. The method according to claim 5 wherein the first and second set of measurements measure a reference symbol receive power (RSRP).
7. The method according to claim 5 wherein the first and second set of measurements measure a reference symbol receive quality (RSRQ).
8. A method in a wireless terminal comprising:
determining, by the wireless terminal, a received signal level threshold for a first base station of a first wireless technology, such that when a received signal level of the first base station is below the received signal level threshold, the wireless terminal is unable to decode received signals of the first base station that overlap the wireless terminal's transmission of signals of a second wireless technology; and
performing a handover from the first base station of the first wireless technology to a second base station of the first wireless technology operating on a second frequency distinct from the operating frequency of the first base station when the received signal level of the first base station is below the received signal level threshold; and
indicating, by the wireless terminal, the received signal level threshold to the first base station only when a transceiver of the second wireless technology in the wireless terminal is active.
9. The method of claim 8 further comprising:
performing a first set of measurements on a first received signal on a first operating frequency of the first wireless technology, wherein the first set of measurements are performed during time periods that overlap time periods during which the wireless terminal transmits signals of the second wireless technology;
performing a second set of measurements on a second received signal on a first operating frequency of the first wireless technology, wherein the second set of measurements are performed during time periods that do not overlap time periods during which the wireless terminal transmits signals of the second wireless technology;
comparing the first set of measurements with the second set of measurements; and
based on the comparison, sending, by the wireless terminal, an indication of a periodicity of a planned transmission by the wireless terminal where interference may occur.
10. The method according to claim 8 , wherein the wireless terminal is configured to operate as a Wi-Fi access point and wherein the wireless terminal indicates to the first base station that a planned Wi-Fi transmission is expected to occur at a particular time.