A four-element adaptive antenna array for IS-136 PCS base stations

Intelligent antennas for wireless communications-uplink

“…Lucent Technologies engineers have been investigating adaptive algorithms for TDMA systems for several years, specifically for IS-54/136. 5,[8][9][10][23][24][25] This work resulted in a field test of a prototype four-element adaptive antenna system near Lucent's facility in Whippany, New Jersey, in October 1996 and a twoelement product, which will be described in the "TBIA Field Test Results" and "Four-Element Applique Field Test" sections.…”

“…We note that γ enters into the solution as an additive constant to the diagonal elements of the correlation matrix and for this reason is referred to as a diagonal loading factor. 24 Substituting the last equation into (20), we get the estimated symbol .…”

“…Recall that the MRC solution for DQPSK does not require channel tracking, while the adaptive solution does. This can be seen in (21) and (24). Thus, as long as the coherence time of the channel does not approach the symbol duration, the MRC solution will be unaffected by Doppler, while the adaptive algorithm must have a coherence time on the order of its window size to obtain good channel tracking.…”

Technology evolution for mobile and personal communications

“…Advances in DSP are providing the low-cost computational capability that is making intelligent antennas, long known in other contexts, 26 useful for wireless communications. Bell Labs pioneered the practical application of adaptive antenna processing to wireless in the early to mid-1990s, [27][28][29] leading to intelligent antenna features in Lucent's wireless product line. While increasing capacity is their primary focus, some additional benefits of intelligent antennas are their increased cell area coverage, improved call quality, improved mobile battery life, reduced base station amplifier power, improved robustness to imperfect cell location, and their ability to support higher data rates.…”

Power control for wireless packet voice with application to EDGE system

“…It is a common practice that the same training sequence is used for transmission to any MS on a given voice channel. Since the sequence is made known to all MS's current receiving packets or tracking interference on the channel, they can apply various techniques such as [S96, p.541] and [CGM98] to measure the interference (plus noise) power.…”