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The requirement for secondary spectrum usage is the control of secondary generated interference to the primary system. The generated interference from different types of secondary networks can be controlled by adjusting different parameters. The carrier sensing threshold can be used as a common parameter to control the density of active secondary users in wireless networks with contention control...
The estimation of the total interference generated from a secondary system is essential for protecting the primary receivers. However, interference level estimation from a large number of secondary transmitters is a challenging problem. In this paper, we estimate the aggregate interference as an integration over the power spatial density in the secondary system's deployment area. We modify such integration-based...
In this paper, we establish a channel ranking strategy for wireless sensor networks (WSN) in the presence of WLAN interference. The packet delivery ratio (PDR) of a sensor link is the performance metric used for channel ranking. The PDR is defined as a function of the signal-to-interference-and-noise-ratio (SINR) at the sensor and the time domain transmission characteristics of the interferer that...
In US FCC and in Europe ECC have outlined the rules for TV-band secondary use. In this paper we apply those rules and compute how much white space is available in Finland. The results are expressed in terms of available secondary channels and secondary system capacity. As a secondary system we use cellular networks with different cell sizes. Unfortunately, the current secondary spectrum usage rules...
In this paper we investigate the detection of OFDM primary signals using autocorrelation. The conventional model for signal detection in cognitive radio assumes that the primary signal is either absent or present with a fixed level. We show that the conventional model is the source of significant discrepancy between the analytical prediction of the detection algorithm and the simulations. We propose...
The autocorrelation-based detection of OFDM signals with cyclic prefix is an appealing method for cognitive radio because it has low complexity and it allows to separate between different OFDM-based legacy systems. Unfortunately, it is also sensitive to noise estimation errors provided that a single estimate of the autocorrelation function is calculated. In this paper we design an autocorrelation-based...
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