๊ด€๋ฆฌ ๋ฉ”๋‰ด

๋ชฉ๋กDSB (1)

Unfazedโ—๏ธ๐ŸŽฏ

์‹ ํ˜ธ์™€ ์ŠคํŽ™ํŠธ๋Ÿผ - ๋””์ง€ํ„ธ ๋ฐ์ดํ„ฐ์˜ ๋Œ€์—ญํญ (๋ณ€์กฐ, ์–‘์ธกํŒŒ๋Œ€, ๋Œ€์—ญํญ ์ข…๋ฅ˜)

๋ณ€์กฐ : ๋‚ฎ์€ ์ฃผํŒŒ์ˆ˜์˜ ๊ธฐ์ €๋Œ€์—ญ ์‹ ํ˜ธ๋ฅผ ๋ฉ€๋ฆฌ ๋ณด๋‚ด๊ธฐ ์œ„ํ•ด ๋ฐ˜์†กํŒŒ์˜ ์ง„ํญ์ด๋‚˜ ์ฃผํŒŒ์ˆ˜ ๋˜๋Š” ์œ„์ƒ์— ์‹ ํ˜ธ๋ฅผ ์‹ค์–ด ๋ณด๋‚ด๋Š” ๊ธฐ๋ฒ•๊ธฐ์ €๋Œ€์—ญ๊ณผ ๋Œ€์—ญํ†ต๊ณผ ์‹ ํ˜ธ๊ธฐ์ €๋Œ€์—ญ(Baseband): ์›๋ž˜ ์‹ ํ˜ธ์˜ ์ฃผํŒŒ์ˆ˜ ๋Œ€์—ญ๋Œ€์—ญํ†ต๊ณผ(Bandpass): ๊ธฐ์ €๋Œ€์—ญ ์‹ ํ˜ธ๋ฅผ ๋” ๋†’์€ ์ฃผํŒŒ์ˆ˜๋กœ ์ด๋™์‹œํ‚จ ์‹ ํ˜ธ์–‘์ธกํŒŒ๋Œ€(DSB: Double-Sideband) ๋ณ€์กฐ๋ฐฉ์‹: ๊ธฐ์ €๋Œ€์—ญ ์‹ ํ˜ธx(t)์™€ ๋ฐ˜์†กํŒŒ(carrier)์˜ ๊ณฑ => ๋Œ€์—ญํ†ต๊ณผ ์‹ ํ˜ธ xc(t)์ˆ˜์‹: xc(t) = x(t)*cos(2πfct)fc: ๋ฐ˜์†กํŒŒ ์ฃผํŒŒ์ˆ˜xc(t)์— ๋Œ€ํ•œ ํ‘ธ๋ฆฌ์— ๋ณ€ํ™˜ => X(f)=(1/2)[X(f−fc)+X(f+fc)] ๊ธฐ์ €๋Œ€์—ญ ์‹ ํ˜ธ๊ฐ€ ๋ฐ˜์†กํŒŒ ์ฃผํŒŒ์ˆ˜ ์ฃผ์œ„๋กœ ๋Œ€์นญ์ ์œผ๋กœ ๋ณต์‚ฌ๋จ๋‘ ๊ฐœ์˜ ์ธกํŒŒ๋Œ€ ํ˜•์„ฑ์ƒ์ธกํŒŒ๋Œ€(USB: Upper Side Band): fc ~ (fc + fm)ํ•˜..