Bits,Baud,Hz,Rates. ** Baud ** "Baud" is the name for an information "symbol. " Baud are usually sent at a rate known as the "baud rate" (B). The inverse of the "baud rate" is the time it takes to send one baud, the "baud period" (T). B = 1/T (Baud/second) Baud is from the name Baudot. M. Baudot invented the "Baudot code", a five- bit code used on early teletype machines to send letters and numbers. A Baud has a certain number of recognizable states (L). ** Bandwidth (Nyquist) The Nyquist theorem says the maximum bit rate (Rmax, in bits/second) for a channel with bandwidth (H, in Hz) is: Rmax <= 2 H log2(L) Since log2(L) is the number of bits per Baud, so the maximum Baud per second, B; Bmax <= 2 H One can approach this maximum Baud rate only with baseband encoding schemes that have only have one voltage change per Baud (NRZ, NRZI). ** Effect of Noise (Shannon)** ** Exercises ** Back to Home Page.
Bit rate. In telecommunications and computing, bit rate (sometimes written bitrate or as a variable R[1]) is the number of bits that are conveyed or processed per unit of time. The bit rate is quantified using the bits per second (bit/s or bps) unit, often in conjunction with an SI prefix such as kilo- (kbit/s or kbps), mega- (Mbit/s or Mbps), giga- (Gbit/s or Gbps) or tera- (Tbit/s or Tbps). Note that, unlike many other computer-related units, 1 kbit/s is traditionally defined as 1,000 bit/s, not 1,024 bit/s, etc., also before 1999 when SI prefixes were introduced for units of information in the standard IEC 60027-2.[2] Uppercase K as in Kbit/s or Kbps should never be used. [citation needed] The symbol for "bits per second" is "bit/s" (not "bits/s", according to the writing style for SI units).
One byte per second (1 B/s) corresponds to 8 bit/s. Protocol layers [edit] Gross bit rate[edit] In case of serial communications, the gross bit rate is related to the bit transmission time as: Prefixes[edit] Nyquist–Shannon sampling theorem. Fig. 1: Fourier transform of a bandlimited function (amplitude vs frequency) The theorem does not preclude the possibility of perfect reconstruction under special circumstances that do not satisfy the sample-rate criterion.
(See Sampling of non-baseband signals below, and Compressed sensing.) The name Nyquist–Shannon sampling theorem honors Harry Nyquist and Claude Shannon. The theorem was also discovered independently by E. T. Whittaker, by Vladimir Kotelnikov, and by others. Introduction[edit] If a function x(t) contains no frequencies higher than B hertz, it is completely determined by giving its ordinates at a series of points spaced 1/(2B) seconds apart. A sufficient sample-rate is therefore samples/second, or anything larger. The bandlimit for perfect reconstruction is When the bandlimit is too high (or there is no bandlimit), the reconstruction exhibits imperfections known as aliasing. And are respectively called the Nyquist rate and Nyquist frequency. The symbol Aliasing[edit] for all.