History of smart antennas
[3] Edwin H. Armstrong invented the superheterodyne receiver to detect the high frequency noise generated by German warplanes’ ignition systems.
[2] AT&T's decision to use microwave to carry inter-city telephone traffic led to the first large-scale commercial deployment of directional antennas (based on Friis’ horn reflector design[5]) in 1947.
[9] The American Physicist Luis Walter Alvarez developed the first ground-controlled approach (GCA) system for landing aircraft in bad weather based on an electronically steered microwave phased array antenna.
[10] Near the end of the war, Germany's GEMA built an early warning phased array radar system (the PESA Mammut 1) to detect targets up to 300 km away.
[2] A major push to meet national security response time and coverage requirements called for the development of an all-electronic steerable planar phased array radar.
These systems required the development of special techniques for canceling the radar clutter seen from space, nulling ground-based jammers, and compensating for Doppler shifts experienced by fast-moving satellites.
Companies such as Texas Instruments, Raytheon, RCA, Westinghouse, General Electric, and Hughes Electronics participated in the early development of MMICs.
[17] The first adaptive array, the side-lobe canceller, was developed by Paul Howells and Sid Applebaum at General Electric in 1959 to suppress radar jamming signals.
[18] Building on Norbert Wiener’s work with analog filters, in 1960 Stanford University professor Bernard Widrow and PhD student Ted Hoff developed the least mean squares (LMS) algorithm that automatically adjusts an antenna's directivity pattern to reinforce desired signals.
[19] Ted Compton at Ohio State University developed an adaptive antenna technique for recovering direct sequence spread spectrum signals in the presence of narrowband co-channel interference.
[20] In the late 1970s, Kesh Bakhru and Don Torrieri developed the maximin algorithm for recovering frequency hopping signals in the presence of narrowband co-channel interference.
[21] A 1977 paper by Bell Labs researchers Douglas O. Reudink and Yu S. Yeh described the advantages of scanning spot beams for satellites.
The authors estimated that scanning spot beams could save 20 dB in link budget which in turn could be used to reduce transmit power, increase communication capacity, and decrease the size of earth-station antennas.
Its origins go back into methods developed in the 1920s that were used to determine direction of the arrival of radio signals by a set of two antennas based on the phase difference or amplitudes of their output voltages.
Thus, the assessment of the directions of arrival of a single signal was conducted according to pointedtype indicator readings or according to the Lissajous curves, drawn by beam on the oscilloscope screen.
[23] The growing complexity of solving such radar challenges, as well as the need to implement effective signal processing by the end of the 1950s predetermined the use of electronic computers in this field.
Then, there was only to solve the problem of direct digital data, obtained from sensing elements, input into computer, excluding the stage of preparation of punch card and operator assistance as a surplus link.
developed a general theory of multichannel analyzers, based on the processing of information contained in the distribution of complex voltage amplitudes at the outputs of the digital antenna array.
[33] Brian Agee and John Treichler developed the constant modulus algorithm (CMA) for blind equalization of analog FM and telephone signals in 1983.
[35][36] During the 1990s companies such as Applied Signal Technology (AST) developed airborne systems to intercept digital cellular phone calls and text messages for law enforcement and national security purposes.
[38] In 1947, Douglas H. Ring wrote a Bell Laboratories internal memorandum describing a new way to increase the capacity of metropolitan radio networks.
[41] Richard Roy and Björn Ottersten at Arraycomm patented a space-division multiple access method for wireless communication systems in the early 1990s.
[42] Richard Roy and French entrepreneur Arnaud Saffari founded ArrayComm in 1992 and recruited Marty Cooper, who led the Motorola group that developed the first portable cell phone, to head the company.
[43] Bell Labs researcher Douglas O. Reudink founded Metawave Communications, a maker of switched beam antennas for cellular telephone networks, in 1995.
Researchers studying the transmission of multiple signals over different wires in the same cable bundle helped create a theoretical foundation for 4G MIMO.
The “wireline MIMO” researchers included Lane H. Brandenburg and Aaron D. Wyner (1974),[46] Wim van Etten (1970s),[47] Jack Salz (1985),[48] and Alexandra Duel-Hallen (1992).
[51] Bell Labs researcher Gerard J. Foschini’s paper submitted in September 1996 and published in October of the same year also theorized that MIMO could be used to significantly increase the capacity of point-to-point wireless links.
OFDM emerged in the 1950s when engineers at Collins Radio Company found that a series of non-contiguous sub-channels are less vulnerable to inter-symbol interference (ISI).
The company built a prototype MIMO-OFDM fixed wireless link running 100 Mbit/s in 20 MHz of spectrum in the 5.8 GHz band, and demonstrated error-free operation over six miles with one watt of transmit power.
[69] The Institute of Electrical and Electronics Engineers (IEEE) created a task group in late 2003 to develop a wireless LAN standard delivering at least 100 Mbit/s of user data throughput.
