Effective spectrum allocation schemes in wireless communication system such as CDMA systems are addressed in this work. Almost all the wireless networks have varying traffic pattern over temporal and regional load characteristics.
These time varying patterns are seen on most RANs, as a consequence of user behavior change depending on the time of day, and also the day of each week. Regional variations in the traffic are caused by the spatially unequal population density and variations in the activities of the population depending on the area e.g. business or recreation facility.
Using these temporally varying characteristics of traffic load, some practical dynamic spectrum allocation (DSA) algorithms are proposed to achieve high spectral efficiency: the ratio allocation based on the arrival rate and the power allocation based on the channel power in CDMA networks.
With fixed-assigned spectrum, the capacity of the system is reserved to handle the maximum traffic load with some level of assurance. However, most of the spectrum will be unused for long periods of time during the low load intervals.
A DSA algorithm shares spectrum between networks by allowing spectrum to be taken from one RAN and allocated to another at times when and where the load is low enough for certain spectrum not to be required. This work discusses the potential gains in spectrum efficiency to be made from using the DSA algorithms.
With this scheme, the spectrum to be dynamically allocated is treated as a single pool, and any operator can be assigned an arbitrary piece of spectrum anywhere in this pool. The traffic pattern plays a major part in the operation of an algorithm, it should be possible to predict with absolute accuracy through traffic statistics for long time. In this work, the DSA algorithm uses different time-varying traffic pattern which is based on the real CDMA traffic data from KTF in Korean CDMA operator.
We have presented the performance of the DSA algorith...