Variable Spreading Factor Orthogonal Frequency and Code Division Multiplexing (VSF-OFCDM)

A Complete Mathematical Modeling and Simulation of Ergodic Channel Capacity of Wireless Random MIMO System

“…Gain of transmitting antenna is and gain of receiving antenna is . Received power at distance d is expressed by well-known Friss equation [20][21][22][23][24].…”

“…Figure 7 shows the log distance path loss at the carrier frequency of 1.5GHz. it is clear that the path loss increase with the path loss exponent n. even if the distance between transmitter and receiver is equal to each other every path have different path loss [29] [35]. Let denote a Gaussian random variable with zero mean and standard deviation of σ then the log normal shadowing model can be written as…”

“…The channel correlation is directly related to capacity of MIMO channel. Also we consider the capacity of MIMO channel when the channel gain between transmitter and receiver is correlated [20][21]. When the SNR is high the deterministic channel capacity can be written as…”

Evolution towards broadband wireless systems

“…MC-CDMA can fill the gap between OFDM and DS-CDMA [13]. The former can overcome frequency-selective fading by adopting a relatively low-complexity receiver (a simple one-tap equalizer per sub-carrier), while the latter gives multi-access capability, multi-rate transmission, single-frequency reuse, etc.…”

“…The use of SF>1 allows singlefrequency reuse similarly to 3G, while SF=1 can be used to cover hotspot areas, resulting in a single-cell system using OFDM [13], as illustrated in Fig. 10 (similar design can be applied to DS-CDMA).…”