TY - JOUR
T1 - Cochannel interference reduction in dynamic-TDD fixed wireless applications, using time slot allocation algorithms
AU - Jeong, Wuncheol
AU - Kavehrad, Mohsen
N1 - Funding Information:
Paper approved by V. A. Aalo, the Editor for Diversity and Fading Channel Theory of the IEEE Communications Society. Manuscript received June 21, 2001; revised April 2, 2002 and April 20, 2002. This work was supported by the National Science Foundation under Grant CCR-9902864 and the Pennsylvania State University Center for Information and Communications Technology Research (CICTR). This paper was presented in part at the 35th Asilomar Conference on Signals, Systems, and Computers, Pacific Grove, CA, November 2001; the IEEE Vehicular Technology Conference, Atlantic City, NJ, October 2001; and the IEEE Radio and Wireless Conference (RAWCON), Boston, MA, August 2001.
PY - 2002/10
Y1 - 2002/10
N2 - In this paper, we consider a fixed wireless cellular network that uses dynamic time division duplex (D-TDD). We analyze the signal-to-interference ratio (SIR) outage performance of a D-TDD fixed cellular system, and propose a scheme to improve the outage probability performance. First, outage probability is evaluated using an analytical model, when omnidirectional antennas are deployed at a base-station site and a subscriber site. Our model is verified, using Monte Carlo simulations. According to our investigation, the outage performance of the D-TDD system is severely limited by a strong interference from the cochannel cell on the downlink, while the reference cell is in the uplink cycle. To improve the outage performance during uplink receptions, we introduce two time-slot allocation methods, combined with sector antennas: the Max Min{SIR} and Max{SIR}. The Max Min{SIR} is an exhaustive search algorithm for assigning subscribers to a few extra uplink time slots, so as to maximize the minimum SIR expectation value over the extra uplink time-slots region. It is used as a performance benchmark in our analysis. Meanwhile, the Max{SIR} is a simpler and efficient algorithm for improving the outage performance. It is established that the performance difference between the two algorithms is not noticeable. Especially, the difference is negligible, when the dynamic range of the traffic pattern between uplink and downlink is small. Also, the outage performance of a system that employs the Max{SIR} algorithm combined with sectored antennas is compared to that of a system employing adaptive-array antennas. The proposed system shows promise, and offers a compromise between system complexity and network guaranteed availability.
AB - In this paper, we consider a fixed wireless cellular network that uses dynamic time division duplex (D-TDD). We analyze the signal-to-interference ratio (SIR) outage performance of a D-TDD fixed cellular system, and propose a scheme to improve the outage probability performance. First, outage probability is evaluated using an analytical model, when omnidirectional antennas are deployed at a base-station site and a subscriber site. Our model is verified, using Monte Carlo simulations. According to our investigation, the outage performance of the D-TDD system is severely limited by a strong interference from the cochannel cell on the downlink, while the reference cell is in the uplink cycle. To improve the outage performance during uplink receptions, we introduce two time-slot allocation methods, combined with sector antennas: the Max Min{SIR} and Max{SIR}. The Max Min{SIR} is an exhaustive search algorithm for assigning subscribers to a few extra uplink time slots, so as to maximize the minimum SIR expectation value over the extra uplink time-slots region. It is used as a performance benchmark in our analysis. Meanwhile, the Max{SIR} is a simpler and efficient algorithm for improving the outage performance. It is established that the performance difference between the two algorithms is not noticeable. Especially, the difference is negligible, when the dynamic range of the traffic pattern between uplink and downlink is small. Also, the outage performance of a system that employs the Max{SIR} algorithm combined with sectored antennas is compared to that of a system employing adaptive-array antennas. The proposed system shows promise, and offers a compromise between system complexity and network guaranteed availability.
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U2 - 10.1109/TCOMM.2002.803991
DO - 10.1109/TCOMM.2002.803991
M3 - Article
AN - SCOPUS:0036811322
SN - 0090-6778
VL - 50
SP - 1627
EP - 1636
JO - IEEE Transactions on Communications
JF - IEEE Transactions on Communications
IS - 10
ER -