Different modulation methods corresponding to different transmitting abilities in air interface. R99/R4: QPSK HSDPA: QPSK or 16QAM The UTRAN air interface uses QPSK modulation in the downlink, although HSDPA may also employ 16 Quadrature Amplitude Modulation (16QAM). 16QAM requires good radio conditions to work well. As seen, with 16QAM also the amplitude of the signal ... Read more
How Orthogonal Code works in WCDMA? 1.Coding By spreading, each symbol is multiplied with all the chips in the orthogonal sequence assigned to the user. The resulting sequence is processed and is then transmitted over the physical channel along with other spread symbols. In this figure, 4-digit codes are used. The product of the user ... Read more
Quadrature Amplitude Modulation (QAM) is a modulation scheme used in various communication systems, including WiFi, to transmit digital data over radio frequencies. In the context of WiFi, QAM plays a crucial role in encoding and decoding information for efficient and reliable wireless communication. At its core, QAM is a method of signal modulation that conveys ... Read more