Further Rotation Modulation Application January 2010 doc.: IEEE 802.11-10/0084r3 Further Rotation Modulation Application Date: 2010-07-12 Authors: Brian Hart, Cisco Systems

Abstract According to the IEEE 802.11-10/0433r2 document, the rotation modulation technique has already been adopted in QPSK modulation. Based on our recent research, this technique can also improve the performance of 16QAM and 64QAM modulations. Therefore, we recommend to introduce this scheme for 16QAM and 64QAM.

Rotation modulation IEEE 802.11-10/0433r2 document has adopted rotation modulation technique in QPSK modulation. The process of rotation modulation is The rotation matrix for QPSK is

Our Proposed Rotation Matrix However, based on our research, the rotated 16QAM and 64QAM modulations also exhibits obvious SNR gain as well. Modulation Proposed Rotation Matrix 16QAM 64QAM

Simulation Parameters Values PHY scheme OFDM Length of FFT 512 Number of subcarriers 355 Code Type LDPC in Draft 0.1 Code Rate 1/2, 3/4, 5/8, 13/16 Modulation Type QPSK, 16QAM, 64QAM Channel Type Conference Room STA-STA [2]

Rotation Modulation NLOS R=1/2 & 5/8 Slide 6

Rotation Modulation NLOS R= 3/4 & 13/16

Gain of Rotation Modulation (NLOS) Gain (FER=0.01) QPSK 16QAM 64QAM 13/16 1.5 1.0 0.8 3/4 0.9 0.6 0.5 5/8 0.3 0.2 1/2

Rotation Modulation LOS R=13/16 For LOS channel, rotation modulation still exhibits better performance.

Conclusions For NLOS-OFDM system, rotation modulation has obvious performance gain over conventional modulations, especially for high code rates. The gain of rotated 16QAM is up to 1.0 dB The gain of rotated 64QAM is up to 0.8 dB For LOS-OFDM system, the rotation modulation still exhibits better performance. In a word, rotation modulation is applicable to 16QAM and 64QAM.

Comment-1 Change to 21.5.3.2.3.3 16-QAM Modulation Add the following sentences at the end of 21.5.3.2.3.3: Each pair of constellation points is converted into where the matrix and the indices P(k), in the range NSD /2 to NSD-1, are as defined in 21.5.3.2.5. The output is the stream of blocks

Comment-2 Change to 21.5.3.2.3.4 64-QAM Modulation Add the following sentences at the end of 21.5.3.2.3.4: Each pair of constellation points is converted into where the matrix and the indices P(k), in the range NSD /2 to NSD-1, are as defined in 21.5.3.2.5. The output is the stream of blocks

References 1. IEEE P802.11 Wireless LANs PHY/MAC Complete Proposal Specification, 2010-05-18 2. IEEE P802.11 Wireless Channel Models for 60 GHz WLAN Systems, 2010-05-20 3. J.Boutros, E.Viterbo, Signal Space Diversity: a power and bandwidth efficient diversity technique for the Rayleigh fading channel. IEEE Trans. Inform.Theory, vol.44. pp.1453-1467, July 1998 . 4. Wu Zhanji, A novel Coding-Rotated-Modulation OFDM scheme, International Conference on Communication Technology and Application 2009, ICCTA 2009, October, 2009, pp:517-520