In a conference, considering the packets only f i o m a set of selected clients can reduce the degradation of the quality of speech because mixing packets from all clients can lead to lack of clarity in the speech of any participants. The automatic selection should be smooth arid should not cause frequent interruptions. A method of selecting the clients f o r mixing is suggested here based on a...

Non orthogonal multiple access (NOMA) in the downlink is discussed in this letter. When combined with soft frequency reuse, NOMA is detrimental to user fairness by increasing the data rate of a near user at the cost of data rate of a far user.

The paper carries out performance analysis of a multiuser full-duplex (FD) communication system. Multiple FD UEs share the same spectrum resources, simultaneously, at both the uplink and downlink. This results in co-channel interference (CCI) at the downlink of a UE from uplink signals of other UEs. This work proposes the use of diversity gain at the receiver to mitigate the effects of the CCI....

Transmit diversity offers an advantage in the forward link of the cdma2000 system by balancing the spectrum efficiency in the uplink and downlink. Three schemes for performing transmit diversity are examined in this paper – orthogonal transmit diversity, time switched transmit diversity, and selection transmit diversity for vehicular, indoor-outdoor pedestrian and indoor office environments. Al...

A method for regenerating a pseudo-noise (PN) ranging signal at a spacecraft is presented. This method allows for an increase of up to 30 dB in received downlink ranging power. The increased power can be used to decrease the measurement uncertainty, reduce the time of the measurement, or increase the power allocated to the downlink telemetry. This system is being implemented in the Spacecraft T...

Given an oriented link L in 3-space we consider a generic homotopy connecting L with the unlink. To each singular link in the homotopy we associate some polynomial using an extension of the Kauffman bracket. The signed sum of these polynomials is a new link invariant, called Cross(L). It is determined by the following skein relations: Cross(unlink) = 0 Cross(L+)− Cross(L−) = t −1/2V (L+) + t 1/...

For every n–component ribbon link L we prove that the Jones polynomial V(L) is divisible by the polynomial V(©n) of the trivial link. This integrality property allows us to define a generalized determinant det V(L) := [V(L)/V(©)](t 7→−1) , for which we derive congruences reminiscent of the Arf invariant: every ribbon link L = K1∪· · ·∪Kn satisfies det V(L) ≡ det(K1) · · · det(Kn) modulo 32, whe...

Suppose L is a link in S3. We show that π1(S3−L) admits an irreducible meridian-traceless representation SU(2) if and only not the unknot, Hopf link, or connected sum of links. As corollary, neither unknot nor link. This result generalizes theorem Kronheimer Mrowka to case