A novel approach in quantifying code orthogonality factor for UTRA-FDD systems is extended in this paper to include the impact of down-link beamforming. The effects of fixed beam forming on code orthogonality is analysed through the aid of real channel data taken from urban cellular environments. The results show a significant overall improvement in code orthogonality with beam forming, especia...

Lysenin, a 297 amino acid pore-forming protein extracted from the coelomic fluid of the earthworm E. foetida, inserts constitutively open large conductance channels in natural and artificial lipid membranes containing sphingomyelin. The inserted channels show voltage regulation and slowly close at positive applied voltages. We report on the consequences of slow voltage-induced gating of lysenin...

Smart antenna using multiple antennas exploring the SDMA technology has been used in wireless communication systems which provides higher spectrum efficiency, improved link quality and throughput through frequency reuse, reduction of intersymbol interference (ISI) and co-channel interference rejection (CCI)[1]. Space Division Multiple Access, where multiple user signals are simultaneously trans...

A synthetic 22-mer peptide that mimics the sequence of a putative pore segment of the voltage-dependent sodium channel forms transmembrane ionic channels in lipid bilayers. Several features of the authentic sodium channel are exhibited by the synthetic peptide: (i) The single channel conductance of the most frequent event is 20 pS in 0.5 M NaCl. (ii) The single channel open and closed lifetimes...

To understand the molecular mechanism of ligand-induced gating of the inositol 1,4,5-trisphosphate (IP(3)) receptor (IP(3)R)/Ca(2+) release channel, we analyzed the channel properties of deletion mutants retaining both the IP(3)-binding and channel-forming domains of IP(3)R1. Using intrinsically IP(3)R-deficient cells as the host cells for receptor expression, we determined that six of the muta...

ATP-sensitive potassium channels are an octomeric complex of four pore-forming subunits of the Kir 6.0 family and four sulfonylurea receptors. The Kir 6.0 family consists of two known members, Kir 6.1 and Kir 6.2, with distinct functional properties. The tetrameric structure of the pore-forming domain leads to the possibility that mixed heteromultimers may form. In this study, we examine this b...

High-temperature inactivation of passive potassium transport is demonstrated for mouse cell cultures and discussed in analogy to recent results on model systems from phospholipid/cholesterol doted with channel-forming antibiotics.

A COOH-terminal tryptic fragment (Mr approximately equal to 20,000) of colicin E1 has been proposed to contain the membrane channel-forming domain of the colicin molecule. A comparison is made of the conductance properties of colicin E1 and its COOH-terminal fragment in planar bilayer membranes. The macroscopic and single channel properties of colicin E1 and its COOH-terminal tryptic fragment a...

We have cloned cDNAs for the shaker potassium channel gene from the spiny lobster Panulirus interruptus. As previously found in Drosophila, there is alternative splicing at the 5' and 3' ends of the coding region. However, in Panulirus shaker, alternative splicing also occurs within the pore-forming region of the protein. Three different splice variants were found within the P region, two of wh...

Synthetic peptides with sequences representing putative transmembrane (M) segments of CFTR (the cystic fibrosis transmembrane conductance regulator) were used as tools to identify the involvement of such segments in forming the ionic pore of the CFTR Cl- channel. Peptides with sequences corresponding to M2 and M6 form anion-selective channels after reconstitution in lipid bilayers. In contrast,...