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Binary offset carrier modulation [1] [2] (BOC modulation) was developed by John Betz in order to allow interoperability of satellite navigation systems. It is currently used in the US GPS system, Indian IRNSS system and in Galileo [3] and is a square sub-carrier modulation, where a signal is multiplied by a rectangular sub-carrier of frequency equal to or greater than the chip rate.
Multiplexed binary offset carrier (MBOC) modulation [1] [2] [3] is a modulation design proposed for Galileo [2] and modernized GPS satellite navigation signals, which combines a sine binary offset carrier SinBOC(1,1) signal with a SinBOC(6,1) signal, either via weighted sum/difference (the CBOC implementation) or via time-multiplexing (the TMBOC implementation).
The Composite Binary Offset Carrier (CBOC) modulation is a particular implementation of the Multiplexed Binary Offset Carrier modulation and it is nowadays used by Galileo satellite signals. It is formed by addition or subtraction of two weighted sine binary offset carrier modulations. [ 1 ]
Of the total L1C signal power, 25% is allocated to the data and 75% to the pilot. The modulation technique used is BOC(1,1) for the data signal and TMBOC for the pilot. The time multiplexed binary offset carrier (TMBOC) is BOC(1,1) for all except 4 of 33 cycles, when it switches to BOC(6,1).
Open signals L1OC and L2OC use time-division multiplexing to transmit pilot and data signals, with BPSK(1) modulation for data and BOC(1,1) modulation for pilot; wide-band restricted signals L1SC and L2SC use BOC (5, 2.5) modulation for both data and pilot, transmitted in quadrature phase to the open signals; this places peak signal strength ...
Choosing the codes used to modulate the signal is very important in the performance of CDMA systems. The best performance occurs when there is good separation between the signal of a desired user and the signals of other users. The separation of the signals is made by correlating the received signal with the locally generated code of the ...
Categorization for signal modulation based on data and carrier types. In electronics and telecommunications, modulation is the process of varying one or more properties of a periodic waveform, called the carrier signal, with a separate signal called the modulation signal that typically contains information to be transmitted. [1]
The equation above shows that by multiplying the modulated signal by the carrier signal, the result is a scaled version of the original message signal plus a second term. Since , this second term is much higher in frequency than the original message. Once this signal passes through a low pass filter, the higher frequency component is removed ...