**Acknowledgements**

MSAC compared to AP-DCDM is high frequency component at symbol rate. This feature is obtained because MSAC symbols are equipped with guard slot, like DCDM or RZ, therefore, increases the transition density in the modulated signal. As a result, a complex circuit is not required for recovering clock frequency in receiver. This comparison indicates that MSAC provides significant advantages against DCDM and AP-DCDM for multiplexing high speed

*Abbreviations***:** RS, receiver sensitivity; DCDM-ADC, DCDM amplitude distribution controller; DD-MZM, dual drive Mach Zehnder modulator; AP-DCDM, absolute polar DCDM; NMP-DCDM, new multiplexed pattern DCDM; NA, not

**10−9**

DCDM-ADC Yes −28.9 23.35 80 ±93.5 [7]

AP-DCDM No −29 22.82 60 ±109 [9] NMP-DCDM Yes −28.4 23.5 – – [10]

Yes −29.5 21.8 60 ±155

**Table 1.** Performance comparison between various DCDM version and MSAC for 3 × 10 Gbit/s system setup.

Yes −28.85 23.3 80 −59 to +100 [8]

**Spectral width (GHz)**

**CD tolerance (ps/nm)**

**Table 2** shows the performance comparison between DCDM-ADC, AP-DCDM and MSAC for optical transmission system with 40 Gbit/s setup. In general, the performance for all parameters for MSAC with OLS is better than DCDM-ADC. This finding is consistence with the result in **Table 1**. The performance of MSAC is also better than AP-DCDM version with guard slot. The receiver sensitivity for MSAC is inferior when comparing with the optimized level spacing AP-DCDM using DD-MZM, but it has better performance in terms of the spectral width and CD tolerance. Moreover, upgrading MSAC from 3 (3 × 10 Gbit/s) to 4 tributaries (4 × 10 Gbit/s) is achieved without extra spectral width. For ETDM, spectral width of 160 GHz

> **Spectral width (GHz)**

**CD tolerance (ps/nm)**

**10−9**

DCDM-ADC Yes −26 26.38 100 ±58 [7] AP-DCDM Yes −26.8 25.8 100 ±62 [11]

Yes −27.1 24.5 60 ±73.1

**Table 2.** Performance comparison between DCDM, AP-DCDM and MSAC for 4 × 10 Gbit/s setup.

No −31 NA 80 ±68 [12]

data stream in electrical domain.

**Technique Guard slot RS BER @ 10−9 OSNR BER @** 

DCDM with DD-MZM

MSAC with OLS

available.

AP-DCDM with DD-MZM

MSAC with OLS

NA, not available.

**Technique Guard slot RS BER @ 10−9 OSNR BER @** 

82 Optical Fiber and Wireless Communications

This work has been funded by the Ministry of Higher Education, Government of Malaysia under project FRGS/1/2015/TK04/UTHM/03/5.
