Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Filter-Bank-Based Narrowband Interference Detection and Suppression in Spread Spectrum Systems
Introduction to digital modulation Relevant Modulation Schemes (QPSK, GMSK, M-Ary Schemes) Coherent and Differential Reception The impact of the mobile channel on digital modulation
– noise and interference – random FM (narrowband fading) – intersymbol interference (wideband fading
The bit rate defines the rate at which information is passed. l The baud (or signalling) rate defines the number of symbols per second. Each symbol represents n bits, and has M signal states, where M = 2n. This is called M-ary signalling....
Interference suppression and CDMA overlay
7.1 NARROWBAND INTERFERENCE SUPPRESSION
To get an initial insight into the problem, we assume that the received signal after frequency down conversion has the form x(i) = b · c(i) + J (i) + n(i) (7.1)
where at sampling instant iTc , b is data, c(i) is the code, J (i) is the narrowband interference, Tc is the chip interval and n(i) is the Gaussian noise. The receiver structure is shown in Figure 7.1. For the two types of ﬁlters, from Figures 7.2 and 7.3 we deﬁne vectors of input samples and ﬁlter taps as follows: Xi1 =...
The total bandwidth is divided into many narrowband
channels. (200 kHz in GSM) Users are given time slots in a narrowband channel (8
users) Multiple access is orthogonal: users within the cell never
interfere with each other. Interference between users on the same channel in
different cells is minimized by reusing the same channel
only in cells far apart.
Bat and dolphin use sound to survive and have greatly superior capabilities to current
technology with regard to resolution, object identification and material characterisation.
Some bats can resolve some acoustic pulses thousands of times more efficiently than
current technology (Thomas & Moss, 2004 ). Dolphins are capable of discriminating
different materials based on acoustic energy, again significantly out-performing current