TY - JOUR
T1 - A joint power control and interference avoidance code assignment strategy for downlink MC-DS-CDMA with 2D spreading
AU - Chang, Chih Wen
AU - Kuo, Chien Cheng
N1 - Funding Information:
Manuscript received August 25, 2008; revised April 11, 2009 and July 16, 2009; accepted July 21, 2009. The associate editor coordinating the review of this paper and approving it for publication was X. Ma. The authors are with the Institute of Computer and Communication Engineering, National Cheng Kung University, Taiwan (e-mail: cwchang@ee.ncku.edu.tw, goo3323@gmail.com). This work was jointly supported by the National Science Council, Taiwan, under the contracts 96-2221-E-006-020 and 97-2221-E-006-085-MY3. This paper is partially published in the IEEE 67th Vehicular Technology Conference, May 2008, Singapore. Digital Object Identifier 10.1109/TWC.2009.081143
PY - 2009/11
Y1 - 2009/11
N2 - Maintaining the quality-of-service (QoS) requirement by transmission power adjustment while eliminating interference is an important but difficult task in the downlink multicarrier direct-sequence code division multiple access (MC-DSCDMA) systems with two-dimensional (2D) spreading. To achieve this goal, we integrate the power control (PC) mechanism and the interference avoidance code assignment strategy. This joint policy is to firstly eliminate interference via an interference avoidance (IA) code assignment strategy and then maintain the QoS via a power control mechanism. To facilitate the code assignment strategy, a new PC-based multiple access interference (MAI) coefficient is defined through performance analysis. Thanks to the help of the PC-based MAI coefficient, we can evaluate each candidate code by quantitatively predicting the amount of interference produced by a possible code assignment event. With this interference pre-evaluation, the PC mechanism can not only maintain the QoS with less transmission power but also eliminate extra MAI in the system. The simulation results show that the proposed joint scheme can maintain a predefined signal quality and significantly improve the call admission rate while largely reducing the power consumption. The contribution of this paper fills up the missing link between the power control and code assignment in the 2D-spread MC-DS-CDMA systems.
AB - Maintaining the quality-of-service (QoS) requirement by transmission power adjustment while eliminating interference is an important but difficult task in the downlink multicarrier direct-sequence code division multiple access (MC-DSCDMA) systems with two-dimensional (2D) spreading. To achieve this goal, we integrate the power control (PC) mechanism and the interference avoidance code assignment strategy. This joint policy is to firstly eliminate interference via an interference avoidance (IA) code assignment strategy and then maintain the QoS via a power control mechanism. To facilitate the code assignment strategy, a new PC-based multiple access interference (MAI) coefficient is defined through performance analysis. Thanks to the help of the PC-based MAI coefficient, we can evaluate each candidate code by quantitatively predicting the amount of interference produced by a possible code assignment event. With this interference pre-evaluation, the PC mechanism can not only maintain the QoS with less transmission power but also eliminate extra MAI in the system. The simulation results show that the proposed joint scheme can maintain a predefined signal quality and significantly improve the call admission rate while largely reducing the power consumption. The contribution of this paper fills up the missing link between the power control and code assignment in the 2D-spread MC-DS-CDMA systems.
UR - http://www.scopus.com/inward/record.url?scp=70749099206&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=70749099206&partnerID=8YFLogxK
U2 - 10.1109/TWC.2009.081143
DO - 10.1109/TWC.2009.081143
M3 - Article
AN - SCOPUS:70749099206
VL - 8
SP - 5582
EP - 5591
JO - IEEE Transactions on Wireless Communications
JF - IEEE Transactions on Wireless Communications
SN - 1536-1276
IS - 11
M1 - 5336785
ER -