An implementation of a CMA adaptive array for high speed GMSK transmission in mobile communications

Applications Of Antenna Arrays To Mobile Communications, Part I: Performance Improvement, Feasibility, And System Considerations

“…1) Use of Diversity Combining: Diversity combining achieves a reduction in fading by increasing the signal level based upon the level of signal strength at different antennas [20], [66], [125], whereas in multipath cancellation methods, it is achieved by adjusting the beam pattern to accommodate nulls in the direction of late arrivals, assuming them to be as interferences. For the latter case, a beam is pointed in the direction of the direct path or a path along which a major component of the signal arrives, causing a reduction in the energy received from other directions and thus reducing the components of multipath signal contributing to the receiver.…”

An adaptive antenna integrated with automatic gain control for receiver front end

“…If we set up a number of antennas to collect these replicas and then add them together, we can expect that sometimes they will add completely in phase, and at other times they will cancel each other out; most of the time, we will see a medium between these two extremes. If we do the combining more purposefully, however, modifying the gain and phase relationships between the antennas, it is clear from the literature that a great deal can be done to diminish the fading in an RF channel [4,11,12,13]. This will be more fully discussed in Chapter 2.…”

“…It turns out that the pdf for the envelope of the carrier is P(r) = r e -r2/2b , r 0 (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16) …”

“…e-2/2b (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14) where b is the variance calculated in (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12). The envelope of Ez is expressed as r = (T2 +Ts2) 2 .…”

“…In short, the received signal is the sum of a deterministic component and a Rayleigh faded component. This is called a Rician fading channel, and the pdf for the envelope of the carrier is [7] r (2+2)a12 ar' P(r) = _ -e +aI)/2 o (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17) where a is the amplitude of the line-of-sight signal and Io is a zero order modified Bessel function.…”