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IS-95
Interim Standard 95 (IS-95) was the first ever CDMA-based digital cellular technology. It was developed by Qualcomm
Qualcomm
and later adopted as a standard by the Telecommunications Industry Association
Telecommunications Industry Association
in TIA/EIA/ IS-95
IS-95
release published in 1995. The proprietary name for IS-95
IS-95
is cdmaOne. It is a 2G mobile telecommunications standard that uses CDMA, a multiple access scheme for digital radio, to send voice, data and signaling data (such as a dialed telephone number) between mobile telephones and cell sites. CDMA or "code division multiple access" is a digital radio system that transmits streams of bits (PN codes). CDMA permits several radios to share the same frequencies
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OQPSK
Phase-shift keying
Phase-shift keying
(PSK) is a digital modulation process which conveys data by changing (modulating) the phase of a reference signal (the carrier wave). The modulation occurs by varying the sine and cosine inputs at a precise time. It is widely used for wireless LANs, RFID and Bluetooth
Bluetooth
communication. Any digital modulation scheme uses a finite number of distinct signals to represent digital data. PSK uses a finite number of phases, each assigned a unique pattern of binary digits. Usually, each phase encodes an equal number of bits. Each pattern of bits forms the symbol that is represented by the particular phase. The demodulator, which is designed specifically for the symbol-set used by the modulator, determines the phase of the received signal and maps it back to the symbol it represents, thus recovering the original data
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Frequency-division Multiplexing
In telecommunications, frequency-division multiplexing (FDM) is a technique by which the total bandwidth available in a communication medium is divided into a series of non-overlapping frequency bands, each of which is used to carry a separate signal. This allows a single transmission medium such as a cable or optical fiber to be shared by multiple independent signals. Another use is to carry separate serial bits or segments of a higher rate signal in parallel. The most natural example of frequency-division multiplexing is radio and television broadcasting, in which multiple radio signals at different frequencies pass through the air at the same time. Another example is cable television, in which many television channels are carried simultaneously on a single cable
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Radiotelephone
A radiotelephone (or radiophone) is a communications system for transmission of speech over radio. Radiotelephone systems are very rarely interconnected with the public "land line" (POTS/PSTN) telephone network, and in some radio services, including GMRS,[1] such interconnection is prohibited. "Radiotelephony" means transmission of sound (audio) by radio, in contrast to radiotelegraphy (transmission of telegraph signals) or video transmission
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Shannon's Theorem
In information theory, the noisy-channel coding theorem (sometimes Shannon's theorem), establishes that for any given degree of noise contamination of a communication channel, it is possible to communicate discrete data (digital information) nearly error-free up to a computable maximum rate through the channel
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Viterbi Decoder
A Viterbi decoder
Viterbi decoder
uses the Viterbi algorithm
Viterbi algorithm
for decoding a bitstream that has been encoded using convolutional code or trellis code. There are other algorithms for decoding a convolutionally encoded stream (for example, the Fano algorithm). The Viterbi algorithm
Viterbi algorithm
is the most resource-consuming, but it does the maximum likelihood decoding. It is most often used for decoding convolutional codes with constraint lengths k<=3, but values up to k=15 are used in practice. Viterbi decoding was developed by Andrew J. Viterbi
Andrew J

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Autocorrelation
Autocorrelation, also known as serial correlation, is the correlation of a signal with a delayed copy of itself as a function of delay. Informally, it is the similarity between observations as a function of the time lag between them
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Walsh Codes
The Hadamard code is an error-correcting code that is used for error detection and correction when transmitting messages over very noisy or unreliable channels. In 1971, the code was used to transmit photos of Mars back to Earth from the NASA space probe Mariner 9.[1] Because of its unique mathematical properties, the Hadamard code is not only used by engineers, but also intensely studied in coding theory, mathematics, and theoretical computer science. The Hadamard code is named after the French mathematician Jacques Hadamard. It is also known under the names Walsh code, Walsh family,[2] and Walsh–Hadamard code[3] in recognition of the American mathematician Joseph Leonard Walsh. The Hadamard code is an example of a linear code over a binary alphabet that maps messages of length k displaystyle k to codewords of length 2 k displaystyle 2^ k
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PN Sequences
A pseudorandom binary sequence (PRBS) is a binary sequence that, while generated with a deterministic algorithm, is difficult to predict[1] and exhibits statistical behavior similar to a truly random sequence. PRBS are used in telecommunication, encryption, simulation, correlation technique and time-of-flight spectroscopy.Contents1 Details 2 Practical implementation 3 Notation 4 See also 5 References 6 External linksDetails[edit] A binary sequence (BS) is a sequence a 0 , … , a N − 1 displaystyle a_ 0 ,ldots ,a_ N-1 of N displaystyle N bits, i.e. a j ∈ 0 , 1 displaystyle a_ j in 0,1 for j = 0 , 1 , . .
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Walsh Code
The Hadamard code is an error-correcting code that is used for error detection and correction when transmitting messages over very noisy or unreliable channels. In 1971, the code was used to transmit photos of Mars back to Earth from the NASA space probe Mariner 9.[1] Because of its unique mathematical properties, the Hadamard code is not only used by engineers, but also intensely studied in coding theory, mathematics, and theoretical computer science. The Hadamard code is named after the French mathematician Jacques Hadamard. It is also known under the names Walsh code, Walsh family,[2] and Walsh–Hadamard code[3] in recognition of the American mathematician Joseph Leonard Walsh. The Hadamard code is an example of a linear code over a binary alphabet that maps messages of length k displaystyle k to codewords of length 2 k displaystyle 2^ k
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Media Access Control
In IEEE 802
IEEE 802
LAN/MAN standards, the medium access control (MAC) sublayer (also known as the media access control sublayer) and the logical link control (LLC) sublayer together make up the data link layer. Within that data link layer, the LLC provides flow control and multiplexing for the logical link (i.e. EtherType, 802.1Q VLAN tag etc), while the MAC provides flow control and multiplexing for the transmission medium. These two sublayers together correspond to layer 2 of the OSI model. For compatibility reasons, LLC is optional for implementations of IEEE 802.3 (the frames are then "raw"), but compulsory for implementations of all other IEEE 802
IEEE 802
standards
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PHY
PHY is an abbreviation for the physical layer of the OSI model
OSI model
and refers to the circuitry required to implement physical layer functions. A PHY connects a link layer device (often called MAC as an abbreviation for medium access control) to a physical medium such as an optical fiber or copper cable
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American National Standards Institute
The American National Standards Institute
American National Standards Institute
(ANSI, /ˈænsi/ AN-see) is a private non-profit organization that oversees the development of voluntary consensus standards for products, services, processes, systems, and personnel in the United States.[3] The organization also coordinates U.S. standards with international standards so that American products can be used worldwide. ANSI accredits standards that are developed by representatives of other standards organizations, government agencies, consumer groups, companies, and others. These standards ensure that the characteristics and performance of products are consistent, that people use the same definitions and terms, and that products are tested the same way
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QPSK
Phase-shift keying
Phase-shift keying
(PSK) is a digital modulation process which conveys data by changing (modulating) the phase of a reference signal (the carrier wave). The modulation occurs by varying the sine and cosine inputs at a precise time. It is widely used for wireless LANs, RFID and Bluetooth
Bluetooth
communication. Any digital modulation scheme uses a finite number of distinct signals to represent digital data. PSK uses a finite number of phases, each assigned a unique pattern of binary digits. Usually, each phase encodes an equal number of bits. Each pattern of bits forms the symbol that is represented by the particular phase. The demodulator, which is designed specifically for the symbol-set used by the modulator, determines the phase of the received signal and maps it back to the symbol it represents, thus recovering the original data
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Bit
The bit (a portmanteau of binary digit)[1] is a basic unit of information used in computing and digital communications. A binary digit can have only one of two values, and may be physically represented with a two-state device. These state values are most commonly represented as either a 0or1. The two values of a binary digit can also be interpreted as logical values (true/false, yes/no), algebraic signs (+/−), activation states (on/off), or any other two-valued attribute. The correspondence between these values and the physical states of the underlying storage or device is a matter of convention, and different assignments may be used even within the same device or program
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Multiple Access
In telecommunications and computer networks, a channel access method or multiple access method allows several terminals connected to the same multi-point transmission medium to transmit over it and to share its capacity.[1] Examples of shared physical media are wireless networks, bus networks, ring networks and point-to-point links operating in half-duplex mode. A channel access method is based on multiplexing, that allows several data streams or signals to share the same communication channel or transmission medium. In this context, multiplexing is provided by the physical layer. A channel access method is also based on a multiple access protocol and control mechanism, also known as media access control (MAC). Media access control deals with issues such as addressing, assigning multiplex channels to different users, and avoiding collisions
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