Error Detection and Correction for Coding Schemes

2013 ◽  
pp. 179-215
Keyword(s):  
Error Detection ◽  
Coding Schemes ◽  
Error Detection And Correction

scholarly journals A BLOCK COPROCESSOR FOR USER DATA RATE IMPROVEMENTS TO GPRS CODING SCHEME 4

2007 ◽  
Vol 16 (04) ◽  
pp. 541-551 ◽  
Author(s):  
R. SIMON SHERRATT ◽  
KAI ZHANG ◽  
OWEN J. WILKES
Keyword(s):  
Error Detection ◽  
Data Rate ◽  
Mobile Internet ◽  
Full Duplex ◽  
Coding Scheme ◽  
Coding Schemes ◽  
Data Rates ◽  
Error Detection And Correction ◽  
Field Programmable ◽  
User Data

The general packet radio service (GPRS) has been developed to allow packet data to be transported efficiently over an existing circuit-switched radio network, such as GSM. The main application of GPRS are in transporting Internet protocol (IP) datagrams from web servers (for telemetry or for mobile Internet browsers). Four GPRS baseband coding schemes are defined to offer a trade-off in requested data rates versus propagation channel conditions. However, data rates in the order of > 100 kbits/s are only achievable if the simplest coding scheme is used (CS-4) which offers little error detection and correction (EDC) (requiring excellent SNR) and the receiver hardware is capable of full duplex which is not currently available in the consumer market. A simple EDC scheme to improve the GPRS block error rate (BLER) performance is presented, particularly for CS-4, however gains in other coding schemes are seen. For every GPRS radio block that is corrected by the EDC scheme, the block does not need to be retransmitted releasing bandwidth in the channel and improving the user's application data rate. As GPRS requires intensive processing in the baseband, a viable field programmable gate array (FPGA) solution is presented in this paper.

scholarly journals Optical Comparison Operation for 8-Bit QPSK-Modulated Signal by Using Serially-Cascaded Delay Line Interferometer

2018 ◽  
Vol 8 (9) ◽  
pp. 1440 ◽  
Author(s):  
Yohei Aikawa
Keyword(s):  
Error Detection ◽  
Communication Systems ◽  
Delay Line ◽  
Hamming Distance ◽  
Code Word ◽  
Modulation Format ◽  
Comparison Operation ◽  
Error Detection And Correction ◽  
All Optical ◽  
Shift Keying

An all-optical comparator is desirable to realize large-capacity, fully-transparent, and energy-efficient communication systems, as it is considered to be a fundamental component to perform most of the operations, including packet switching, label recognition, error detection and correction, and so on. However, most of the previous studies have been confined to the on–off keying (OOK) modulation format, not phase-shift keying (PSK) modulation. In this paper, the author provides a novel optical comparator designed for quadrature PSK (QPSK)-modulated signal, which comprises a code word with 8-bit length, using a serially-cascaded delay line interferometer. The proposed comparator yields constellations having the information of a Hamming distance based on the designed code, when several patterns of QPSK signal are injected into the comparator. The paper experimentally demonstrates the feasibility of the optical comparison operation for 8-bit QPSK-modulated return-to-zero (RZ) signal at 10 Gbaud.

Sign in / Sign up

Export Citation Format

Share Document