JVC Professional

APRIL 2007

NAB-2007

The ProHD Report

But new digital microwave technology often utilizes COFDM multi-carrier transmitter, which enables non-line-of-sight links (multi-path) in metro areas and in special events coverage, coupled with a QAM modulation scheme. Cable television is using 64-QAM and 256-QAM on single carriers to pack hundreds of SD TV channels (and some HD channels) on one coaxial cable. The higher the QAM number, the higher the bitrate transmission capability over a given bandwidth, but, as the QAM number is increased, the receiver input requires an ever stronger signal (higher SNR) to reliably decode the modulation. It is a trade-off between higher bitrates and shorter distances in the HD ENG microwave world. 256-QAM is easily done through a fiber or coaxial cable, as it’s a controlled wired transmission medium, but 256-QAM is very difficult in HD ENG wireless applications, as microwave camera-backs don’t have enough TX power and need to use omni- directional whip antennas for the camera-back TX unit as well as for the RX unit (a requirement for dynamic multi-path “roving” performance), generally resulting in unreliable link for 256-QAM.

JVC ProHD Camcorder with

BMS cost effective

Microwave Camera-back

Fig. 4. JVC’s ProHD ENG camcorder fitted with BMS 2GHz microwave camera-back unit. The BMS camera-back accepts the compressed MPEG-2 TS (Transport Stream) of 20Mbps, modulates 16-QAM and transmits COFDM over 8MHz bandwidth for roving robustness in HD ENG, sports and EFP applications. This space saving ProHD package offers excellent weight distribution both for shoulder- use and for hand-held.

From 18MHz channels down to 12MHz? The 2GHz BAS relocation reduces channel bandwidth to 12MHz. Can 12MHz do the job? For SD links, 12MHz is ample bandwidth. There is even industry talk of being able to provide reliable two channels of 6MHz each within the 12MHz channel for SD service. But with COFDM, you run into a problem called “spectral regrowth” of the large number of carriers within a single channel with COFDM transmission, causing adjacent channel interference due to the out-of-channel spectral regrowth. The solution is to limit the actual COFDM bandwidth to 8MHz within the 12MHz channel, providing for guard bands of 2MHz on each side. Thus the effective COFDM/QAM channel bandwidth becomes only 8MHz in the relocated 2GHz band (referred to as 8MHz pedestal), with the following performance limitations:

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JVC manual JVC Professional April NAB-2007 ProHD Report
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NAB-2007 specifications

The JVC NAB-2007 is a notable entry in the world of professional broadcasting and production equipment, showcased by JVC at the National Association of Broadcasters (NAB) Show in 2007. This camcorder was designed to meet the demanding needs of videographers and broadcasters, emphasizing high-definition video quality and advanced technology.

One of the standout features of the JVC NAB-2007 is its ability to capture high-definition video in various formats. It supports both 720p and 1080i resolutions, allowing users to choose the format that best fits their production needs. This flexibility has made it a popular choice among filmmakers, event videographers, and news organizations looking for quality in their content creation.

The camcorder utilizes JVC’s advanced HD CMOS technology, which enhances image quality by providing better low-light performance and reducing noise. This is coupled with a powerful optical zoom lens that enables users to capture detailed shots from a distance, making it ideal for dynamic shoots where proximity to the subject may be limited.

Another key feature of the JVC NAB-2007 is its ergonomic design, which is crafted for ease of use during extended shooting sessions. The camera is lightweight yet robust, providing operators with comfort and stability. Additionally, the user interface is intuitive, allowing for quick adjustments to settings without disrupting the workflow.

Built-in stabilization features further enhance the usability of the JVC NAB-2007, ensuring that footage remains smooth even during handheld operation. This is particularly advantageous for documentary shoots or on-the-go filming where traditional stabilization rigs may be impractical.

Connectivity options are expansive on the JVC NAB-2007, including HDMI and component outputs, enabling seamless integration with various editing systems and broadcast environments. The camcorder also includes features for live broadcasting, making it versatile for both recorded and real-time production scenarios.

In summary, the JVC NAB-2007 encapsulates a blend of impressive features, cutting-edge technology, and user-centric design, making it a suitable choice for professionals in the broadcasting and film industries seeking reliable and high-quality performance in their equipment.
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