Phase Encoding - Revision history

Jnc: /* External links */ +Good description

2024-04-20T14:25:07Z

‎External links: +Good description

Jnc: /* See also */ +Modified Frequency Modulation

2024-02-12T22:12:47Z

‎See also: +Modified Frequency Modulation

Jnc: /* External links */ +Recorded Magnetic Tape for Information Interchange

2024-02-12T17:41:34Z

‎External links: +Recorded Magnetic Tape for Information Interchange

Jnc: I'm not really happy with this, but I guess this is OK

2024-02-12T16:15:27Z

I'm not really happy with this, but I guess this is OK

New page

'''Phase Encoding''' (usually given as the acronym, '''PE''') is an [[encoding]] technique which is commonly used on [[magnetic storage]].

In PE, there is a change in direction of the [[magnetic field]] flux in the middle of every [[bit]]-time; whether a particular bit is '0' or '1' is indicated by the direction of the flux transition.

The disadvantage of PE is that if there are two consecutive bits of the same value, there must be reversal in the flux direction, from that resulting from the storage of the first bit (back to the opposite direction), at around the end of the first bit's [[clock]] time, so that the appropriate change in flux direction can be made at the ''next'' bit-time. Obviously, if there were a long string of bits of the same value, this would repeat; this means that the magnetic medium had to be capable of supporting a rate of twice as many changes in the direction of magnetization as the rate of the raw data to be stored on it.

{{semi-stub}}

==See also==

* [[Non Return to Zero]]
* [[Non Return to Zero Inverted]]

[[Category: Theory]]

← Older revision		Revision as of 14:25, 20 April 2024
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	* [https://dl.acm.org/doi/pdf/10.1145/362790.362799 Proposed American National Standard - Recorded Magnetic Tape for Information Interchange] - covers PE		* [https://dl.acm.org/doi/pdf/10.1145/362790.362799 Proposed American National Standard - Recorded Magnetic Tape for Information Interchange] - covers PE
		+	* [http://www.bitsavers.org/pdf/dec/magtape/ta79/EK-OTA79-TM-001_Mar88.pdf TA79, TU79, TA78, TU78 Magnetic Tape Subsystem Technical Manual] (EK-OTA79-TM-001) - contains a good description of the PE format in Section 1.4.1

	[[Category: Device Basics]]		[[Category: Device Basics]]

@@ Line 11: / Line 11: @@
 * [[Non Return to Zero]]
 * [[Non Return to Zero Inverted]]
-==External links=
+==External links==
 * [https://dl.acm.org/doi/pdf/10.1145/362790.362799 Proposed American National Standard - Recorded Magnetic Tape for Information Interchange] - covers PE
-[[Category: Theory]]
+[[Category: Device Basics]]