My Research Continued

After presenting my research to the team last week, Max suggested I find more about the HDTV signal we'll be transmitting, such as its modulation type, bandwidth, and frequency. In addition, Professor Grbic suggested a reading in the coursepack for lecture today, and the topic of discussion is link design and link budget. The readings of pertinence to our design are p.125-134 and p.149-159 of the coursepack. These sections will be valuable in our understanding of requirements for design. Note that spring break is next week, so there will not be a group meeting during the week. Our project review comes the second week after we return to class, namely on March 12/13.

In response to Max's request, I have found the following information that should useful in our design:

Quadrature phase shift modulation, eight phase shift modulation, and sixteen quadrature amplitude modulation are specified, where the bandwidth efficiency improves respectively for the schemes listed, and in order to send a signal with the same quality, the power delivered must increase.

There is also mention of forward error coding (FEC), which adds inormation to the signal to improve the reconstruction at the demodulator on the recevier, and it descreases power consumtion for transmission, but it takes more bandwidth.

Refer to source for system interface of transmission (p.10), error performance requirements, including bit error rate (p.14-15),
(Source: www.atsc.org/standards/a_80.pdf)

On the next resource, there is another system definition, which defined an alternate transmitter and modulation station that offers two modes, terrestrial broadcast mode (8-VSB), and a high data rate mode(16-VSB).

(Source: http://www.atsc.org/standards/a_53-Part-1-6-2007.pdf)

The bandwidth of the video signal is approximately 6.0MHz, and the frequency of transmitted signal is deendant of the modulation scheme.

These topics must be explored in further depth in order for a successful chance for design. I will be working closely with Max to work out the specifications on the signal type, and we must wok closely with Richie and Dave to make sure our Butler matrix can interface with properly. I plan to study these standards established by the Advanced Television Systems Committee Inc. (ATSC).