Here we are sharing two full forms of PCM –
PCM full form in signal transmission
The full form of PCM is Pulse Code Modulation which is like a technique that converts analogue signals into digital communication. Pulse code modulation is one of the most used noise resistant transmission method. Pulse code modulation needs high transmitter bandwidth for transmission of analogue signal to digital signal.
The pulse code modulation provides an important benefit that is the message in the pulse code modulation is a train of pulses of equal height. This means these pulses can be regenerated almost perfectly any given number of times analogue the propagation path. This is because the information or data is not dependent on the accurate height and shape of these pulses.
This type of modulation like PCM normally used in both the telephone network and pubic as well as private.
There are two basic properties of a pulse code modulation which determines the stream fidelity to the original analogue signal and these two properties are –
Sampling rate that is the number of times per second that samples are taken
The bit depth that decides the possible digital values that can be used to describe every sample.
LPCM
LPCM is a specific type of pulse code modulation which means linear pulse code modulation. In linear pulse code modulation the quantization levels are linearly uniform. This is different than the pulse code modulation encodings where quantization levels depends as the function of amplitude which can be as the A-law algorithm or the U-law algorithm.
Pulse code modulation is more common term used instead of LPCM and it is generally used to present data encoded as Linear pulse code modulation.
PCM history
In 1937 the British engineer name Alec Reeves conceived the use of pulse code modulation or PCM for voice communication while he was unaware of his previous work. Working for the international telephone and telegraph in France it was discovered by Alec reeves. Alec described the theory and PCM advantages however there was no practical application. In 1938 Reeves filed for a French patent however his United States’ patent was granted in 1943. Until his US patent Alec started working at the Telecommunications Research Establishment.
The Bell Labs researches who designed SIGSALY which was encryption equipment for transmission f speech by digital techniques, found the use of Pulse code modulation binary coding and it was already proposed by Alec Reeves.
After that in 1949 Ferranti Canada built a working pulse code modulation for Canadian Navy’s DATAR system. This PCM radio system was capable to transmit digitized radar data over long distances also.
In the late 1940s Pulse code modulation used cathode ray coding tube along with a plate electrode that has encoding perforations.
In 1961 the T-carrier system which used two twisted pair transmission lines to carry out 24 Pulse code modulation telephone calls sampled at 8 KHZ along with 8 bit resolution. This development improved the capacity and quality of call in comparison to the previous frequency division multiplexing schemes.
In the year 1973 adaptive differential pulse code modulation or ADPCM was developed by the P. Cummiskey, Nikil Jayant and James L. Flanagan.
PCM in engineering
The full form of PCM in engineering is Phase change memory which is a non-volatile memory or NVRAM. Phase change memory sometimes is also mentioned as a perfect RAM because of its superior performances characteristics.
This phase transition memory is also mentioned a PCM and the PCRAM by various groups.
The phase-change memory is an innovative type of high speed, high volume memory and high-density technology.
Advantages of PCM
These are some benefits of phase-change memory –
PCM has faster write cycles than NAND flash. NAND flash needs to merge data and information first before it writes new data.
Phase change memory contains lower power needs than NAND.
