Dynamic Digital Channelizer Based on Spectrum Sensing

Abstract

The ability to efficiently channelize a received signal with dynamic sub-channel bandwidths is a key requirement of software defined radio (SDR) systems. The digital channelizer, which is used to split the received signal into a number of sub-channels, plays an important role in SDR systems. In this paper, a design of dynamic digital channelizer is presented. The proposed method is novel in that it employs a cosine modulated filter bank (CMFB) to divide the received signal into multiple frequency sub-bands and a spectrum sensing technique, which is mostly used in cognitive radio, is introduced to detect the presence of signal of each sub-band. The method of spectrum sensing is carried out based on the eigenvalues of covariance matrix of received signal. The ratio of maximum-minimum eigenvalue of each sub-band is vulnerable to noise fluctuation. This paper suggests an optimized method to calculate the ratio of maximum-minimum eigenvalue. The simulation results imply that the design of digital channelizer can effectively separate the received signal with dynamically changeable sub-channel signals.

An Efficient Method for Designing Multiplier-Less Non-uniform Filter Bank Based on Hybrid Method Using CSE Technique

“…Adder gain = (Total adders − calculated adders ) Total adders (12) In this paper, PSO, ABC and hybrid PSO-ABC algorithm have been exploited for designing prototype filter of multiplier-less M-channel NUFB. The fidelity parameters for these optimization algorithms have been selected experimentally and summarized in Table 1.…”

“…The significant performance of CSE technique is obtained in terms of adder gain (reduction in required number of adder), as given in Eq. (12).…”

“…In some applications such as digital hearing aids and in trans multiplexers [16,35], the multirate filter bank is required to be designed with adjustable gain, while a flexible technique is highly desirable in case of software defined radio (SDR) so as to operate as a reconfigurable multi-channel filter bank for different wireless standards [12]. When the filter banks are hardwired, the basic components used in realization of digital filters are adders and multipliers, out of which multipliers are the most expensive and resource consuming components that introduce large complexity in the system [8,11,25,26].…”

Wideband Digital Channelizer based on Spectrum Sensing

“…Eigen value Based Detection Eigen value based detection is semi blind detection scheme which does not need any details of signal to be received. This detection scheme is said to have overcome the short coming of energy detection [1]. This method is based on property of covariance matrix of received signals.…”

“…The key technique is spectrum sensing. It provides awareness about frequency band usage [1]. In radio frequency spectrum, there are two types of users authorized users and unauthorized users.…”