Uplink resource allocation to control intercell interference in a wireless communication system
View Patent ↗Embodiments of the present invention exploit the reciprocity of radio channels in TDD, and longer-term correlation between average uplink and downlink path losses in FDD wireless communication systems to enable distributed schedulers in an enhanced uplink system to allocate uplink transmission resources while preemptively managing intercell interference levels. Each cell's base station transmits a downlink reference signal at a known transmission power level. A mobile station monitors the received signal strength of the downlink reference signals from multiple base stations. The transmitted and received signal strength levels can be used by the mobile station to estimate the amount of intercell interference that the mobile station's uplink transmissions cause, and the mobile station's uplink transmission parameters are adjusted accordingly. In further embodiments, the received reference signal power levels, or values derived therefrom, are transmitted by the mobile station to its serving base station, where a scheduling algorithm uses the information to adjust one or more transmission parameters relating to a grant of uplink transmission resources to the UE, thereby controlling the intercell interference generated by the mobile station's uplink transmissions.
1. A tangible computer program product having executable program code stored therein for performing a method of intercell control by allocating uplink transmission resources in a mobile station of a wireless communication system, the program code operable for performing a method when executed at a mobile station, the method comprising:
receiving at least one serving base station reference signal transmission transmitted at a transmission power level;
receiving at least one non-serving base station reference signal transmission transmitted at a respective power level;
measuring at least one received signal power level corresponding to the at least one serving base station reference signal transmission;
constructing a noise-free version of one of the at least one respective reference signals;
calculating a power of the noise-free version;
estimating an at least one interference power level for the at least one non-serving base station reference signal transmission by a relationship of the noise-free version power level and the measured, received signal power of the at least one respective reference signal;
calculating a figure of merit for transmission to the at least one serving base station, wherein the figure of merit is for adjusting an uplink transmission resource parameter at the mobile station, and is based on a relationship of the at least one received signal power level and the at least one interference power level;
transmitting, to the at least one serving base station, the figure of merit to determine the uplink transmission resource parameter for the mobile station; and
receiving, from the at least one serving base station, the uplink transmission resource parameter in response to the figure of merit, wherein the uplink transmission resource parameter is determined by an uplink scheduler of the at least one serving base station such that an acceptable uplink interference is predicted to be caused to the at least one non-serving base station as a result of a transmission from the mobile station to the at least one serving base station using the uplink transmission resource parameter based in part upon cell uplink path gain information.
2. The tangible computer program product of claim 1 , wherein the interference power level is estimated by a relationship of serving base station path gain and strongest non-serving base station path gain.
3. A mobile station for intercell control of allocating uplink transmission resources comprising:
means for receiving, by a mobile station, at least one serving base station reference signal transmission transmitted at a transmission power level;
means for receiving at least one non-serving base station reference signal transmission transmitted at a respective power level;
means for measuring at least one received signal power level corresponding to the at least one serving base station reference signal transmission;
means for estimating an at least one interference power level for the at least one non-serving base station reference signal transmission;
means for calculating a figure of merit for transmission to the at least one serving base station, wherein the figure of merit is for adjusting an uplink transmission resource parameter at the mobile station, and is based on a relationship of the at least one received signal power level and the at least one interference power level;
means for transmitting, to the base station, the figure of merit to determine the uplink transmission resource parameter for the mobile station; and
means for receiving, from the at least one serving base station, the uplink transmission resource parameter in response to the figure of merit, wherein the uplink transmission resource parameter is determined by an uplink scheduler of the at least one serving base station by generating an estimate of an interfering signal power level of a neighboring base station such that an acceptable uplink interference is predicted to be caused to the at least one non-serving base station as a result of a transmission from the mobile station to the at least one serving base station using the uplink transmission resource parameter based in part upon cell uplink path gain information.
4. The mobile station of claim 3 , wherein the uplink transmission resource parameter is a member of the group of data rate, uplink transmission power, degree or nature of forward error correction, modulation format, and code resource usage.
5. The mobile station of claim 3 , wherein the wireless communication system is described by a Third Generation partnership project Universal Mobile Telecommunication Standard, the base station is a Node-B, and the mobile station is a user equipment (UE).