Method and apparatus for mitigating transmission interference between narrowband and broadband mobile devices

A mobile device capable of operating in an Orthogonal Frequency Division Multiple Access (OFDMA) communication system, the mobile device comprising:

• an at least one receiver that is configured to receive broadband communications and narrowband communications;
• a transmitter that is configured to transmit broadband communications;
• and
• a processor that is configured to:
• detect a geographically or physically proximate narrowband uplink transmission, wherein the narrowband uplink transmission is in close enough spectral proximity to at least one bearer channel of the mobile device to result in interference on the narrowband reception when the mobile device is transmitting and a narrowband mobile device is receiving;
• determine, based on the detected narrowband uplink transmission, a corresponding narrowband downlink frequency;
• monitor the determined narrowband downlink frequency;
• detect a narrowband downlink transmission at the monitored narrowband downlink frequency;
• and
• in response to detecting the narrowband downlink transmission at the monitored narrowband downlink frequency, modify a broadband uplink transmission to ensure the broadband uplink transmission does not interfere with narrowband downlink reception.

A system for mitigating radio frequency interference between narrowband public safety and broadband communications devices, the system comprising:

• a narrowband mobile device configured to transmit and receive narrowband communications;
• and
• a Third Generation Partnership Project (3GPP)-conforming mobile device configured to communicate with a 3GPP-conforming broadband network, wherein the 3GPP-conforming mobile device is configured to mitigate the potential for interference between the narrowband mobile device and the 3GPP-conforming mobile device by:
• detecting a narrowband uplink transmission;
• determining, based on the detected narrowband uplink transmission, a corresponding narrowband downlink frequency;
• monitoring the determined narrowband downlink frequency;
• detecting a narrowband downlink transmission at the monitored narrowband downlink frequency;
• and
• in response to detecting the narrowband downlink transmission at the monitored narrowband downlink frequency, modifying a broadband uplink transmission to ensure the broadband uplink transmission does not interfere with narrowband downlink reception.