Employing DDBPSK in Optical Burst Switched Systems to Enhance Throughput

Reduced OSNR Penalty for Frequency Drift Tolerant Coherent Packet Switched Systems Using Doubly Differential Decoding

“…A key feature of doubly differential decoding is its ability to tolerate very high FOs as demonstrated in [4]. This large FO tolerance was exploited in [3] in the case of an OPS scenario where doubly differential binary phase shift keying was shown to be able to decode coherent optical packets with much shorter waiting times after the switching event of a tunable laser, than single differential binary phase shift keying. It was also stated in [3] that this large FO tolerance would allow for relaxed precision requirements of the tunable lasers' wavelengths.…”

“…This large FO tolerance was exploited in [3] in the case of an OPS scenario where doubly differential binary phase shift keying was shown to be able to decode coherent optical packets with much shorter waiting times after the switching event of a tunable laser, than single differential binary phase shift keying. It was also stated in [3] that this large FO tolerance would allow for relaxed precision requirements of the tunable lasers' wavelengths. However, it is also known that doubly differential decoding suffers a large optical signal to noise ratio (OSNR) penalty, theoretically 4.77dB [4], resulting from adding noise terms together in the decoding process.…”

“…This transient FO problem needs to be overcome to optimize network efficiency; hence, a FO compensation algorithm which can deal with large frequency transients is required. It was shown in [3] that doubly differential decoding can result in a greatly reduced waiting time after a tunable laser switches wavelengths compared with single differential decoding. However, doubly differential decoding can result in required optical signal to noise ratios (OSNR) penalties of 4.77dB in theory for QPSK formatted data [4].…”