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In reaching 5.5 Mbit/s and the full rate of 11 Mbit/s, QPSK is employed, but has to be coupled with complementary code keying. The higher-speed wireless LAN standard, IEEE 802.11g-2003, [10] [12] has eight data rates: 6, 9, 12, 18, 24, 36, 48 and 54 Mbit/s. The 6 and 9 Mbit/s modes use OFDM modulation where each sub-carrier is BPSK modulated.
BPSK is the most simple to understand, so the BPSK concept should be introduced in the lead. In its most simple form a regular sinewave is used to represent binary 0; and a 'cosine' wave (180° phase shift) is used to represent binary 1. This should be supported by a diagram alongside. (You can clip the QPSK image, first line-0110 to illustrate ...
Passband modulation; Analog modulation; AM; FM; PM; QAM; SM; SSB; Digital modulation; ASK; APSK; CPM; FSK; MFSK; MSK; OOK; PPM; PSK; QAM; SC-FDE; TCM; TC-PAM; WDM ...
For BPSK, n = 2; the symbols appear inverted or not. Differential encoding prevents inversion of the signal and symbols, respectively, from affecting the data. Assuming that x i {\displaystyle x_{i}} is a bit intended for transmission and y i − 1 {\displaystyle y_{i-1}} was the symbol just transmitted, then the symbol to be transmitted for x ...
Barker code used in BPSK modulation In wireless communications, sequences are usually chosen for their spectral properties and for low cross correlation with other sequences likely to interfere. In the 802.11 standard, an 11-chip Barker sequence is used for the 1 and 2 Mbit/s rates.
The Krylov–Bogoliubov averaging method allows one to prove that solutions of non-autonomous and autonomous equations are close under some assumptions. Thus, the Costas loop block diagram in the time domain can be asymptotically changed to the block diagram on the level of phase-frequency relations.
Continuous phase modulation (CPM) is a method for modulation of data commonly used in wireless modems.In contrast to other coherent digital phase modulation techniques where the carrier phase abruptly resets to zero at the start of every symbol (e.g. M-PSK), with CPM the carrier phase is modulated in a continuous manner.
For many common constellations including BPSK, QPSK, and 8PSK, these two methods for finding the reference give the same result, but for higher-order QAM constellations including 16QAM, Star 32QAM, 32APSK, and 64QAM the RMS average and the maximum produce different reference values.