Features Nikkei Electronics Asia -- April 2008
WirelessHD 1.0, 4Gbps Radio Standard Completed

Mar 27, 2008 17:45 Nikkei Electronics Asia

A high-speed radio technology, pumping several Gbps, will appear for the home digital audio-visual (AV) equipment market. The eight leading consumer electronics manufacturers promoting the WirelessHD Consortium - including firms such as Matsushita Electric Industrial Co Ltd of Japan, Samsung Electronics Co Ltd of Korea, and Sony Corp of Japan - have completed the WirelessHD (WiHD) Version 1.0 high-speed radio communication standard for data rates of up to 4Gbps, and disclosed it to supporting corporations.

WiHD replaces the wires in the High Definition Multimedia Interface (HDMI) with radio links, and is designed to handle high-definition television (HDTV) video streams between AV equipment. The target is defined as handling full HD (1080p) video without high-efficiency coding. Existing technologies such as wireless local area network (LAN; 20Mbps to 30Mbps) and Ultra Wide-Band (UWB; about 200Mbps) cannot handle 1080p without using high-efficiency coding. According to WirelessHD Consortium chairman John Marshall, "With WiHD we'll be able to make HDMI wireless."

The WiHD standard was hammered out primarily by the above-mentioned three firms, along with other major Japanese and Korean electronics manufacturers such as LG Electronics Inc of Korea, NEC Corp of Japan and Toshiba Corp of Japan (Table 1). Now that televisions displaying 1080p next-gen digital videodisc (DVD) equipment, such as the Blu-ray Disc, HD DVD and other equipment, have become widely available, equipment manufacturers are demanding a wireless technology capable of transmitting full HD video streams without high-efficiency coding (Fig 1).

The first equipment compliant with WiHD is likely to appear from the end of 2008 to early 2009. Matsushita Electric Industrial has already announced plans to ship product in 2009, and both Matsushita and Toshiba exhibited WiHD-compliant prototypes at 2008 International CES, held in Las Vegas January 7-11, 2008.

Low-Cost RF, CMOS

WiHD uses the 60GHz waveband, which is license-free in Japan and the US for about a 7GHz bandwidth, and in Europe for about 9GHz. The wide bandwidth makes it possible to attain a high data transfer rate.
There were two problems with using the band, however: the high cost of transceiver circuits, and the high directionality of the transmissions, which made them difficult to use.

WiHD lowers the cost of the transceiver circuits by using a radio frequency (RF) integrated circuit (IC) manufactured with complementary metal-oxide semiconductor (CMOS) technology. GaAs technology is commonly used in millimeter-wave transceiver circuits, making it hard to lower costs. The use of general-purpose CMOS technology is expected to lower costs to about the level of the costs of wireless LAN.

The key driver in chipping the CMOS RF transceiver is SiBEAM Inc of the US, a leader in the WiHD effort. (See also "WirelessHD Chipsets Find First Applications" in the March 2008 issue of NE Asia.) The firm was established in 2004 by Prof Bob Brodersen of the University of California, Berkeley, an authority in CMOS RF technology. In addition to high-frequency CMOS circuit technology, the company also has antenna control technology. It announced the world's first WiHD chipset in January 2008.

Beam Steering

The company plans to resolve the problem of directionality with antenna control technology. An array of tens of antenna devices will be used, with dynamic adjustment of voltage input to each to adaptively control signal radiation angle in what is generally called "beam steering". In the event that a person or other obstacles block the signal path, for example, interfering with signal transmission, the antenna can search out a new transmission path and continue.

The WiHD transceiver circuit developed by SiBEAM uses a ceramic package measuring about 20mm square as the antenna module. The surface of the module is covered with an array of about 36 antenna elements. The voltage supplied to each is adjusted to control radiation angle. The ceramic package appears to use technology from Kyocera Corp of Japan and others.

To ensure stable data transfer in the home, where there are many obstacles, WiHD utilizes orthogonal frequency division multiplex (OFDM) technology. This is said to improve performance in non-line-of-sight (NLOS) use.

No Disputes for 3 Years

The WirelessHD Consortium has entered into contracts with about 40 firms for the use of WiHD. A number of Japanese firms have already signed up, including Alps Electric Co Ltd of Japan, Murata Manufacturing Co Ltd of Japan and Pioneer Corp of Japan.

Reasonable and Non-Discriminatory (RAND) terms have been adopted to prevent disputes over intellectual property rights between member firms. The rules have also been adopted in the IEEE802.11 wireless LAN standard, for example, and require that member firms enter into a reasonably priced licensing contract. In addition, they are prohibited from legal disputes related to intellectual property rights for three years, in an effort to promote widespread adoption of WiHD.

Intel Swings into Action

With the official disclosure of WiHD, Intel Corp of the US announced it would be a promoter.

Until now, Intel has strongly promoted UWB technology for use in high-speed home wireless networks, but now that it has announced support for WiHD there is a chance it will begin developing millimeter-wave transceiver ICs. According to our sources, Intel has already proposed a next-gen WiHD specification for personal computers. It is apparently considering including specifications to interconnect multiple PCs and support file transfer.

by Hiroki Yomogita

November 2009 cover story

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