Performance of Turbo Coded OFDM Under the Presence of Various Noise Types

Abstract

A telecommunication system uses carriers in order to transmit information through a cable or wirelessly. If each time only one carrier is transmitted, then the system's signal will not be immune to frequency selective fading. If frequency selective fading includes the working frequency of the system, then the wireless link will not be established. Orthogonal Frequency Division Multiplexing (OFDM) is the primary solution for coping with inter-signal interference and frequency-selective fading. Many carriers can be produced by splitting a fast information stream to slower data series. Different orthogonal frequencies carry slower data series. System's performance can be further enhanced with the utilization of Turbo Codes. Turbo codes make the system more immune to noise effects with excellent BER results. This paper presents the thorough analysis of a Turbo Coded OFDM scheme using a PCCC technique in the presence of a channel which includes AWGN, Phase noise (PN), Rayleigh fading, Rician fading and Doppler shift.

Performance limit of AOA-based localization using MIMO-OFDM channel state information

“…As a result of [24], we note that the CRLB of φ q,0,m based on the (2K + 1) sample observation of H q,k,m is inversely proportional to |g q,0 | 2 (2K + 1) for large K. Recall that B = (2K + 1) , and |g q,0 | 2 B is proportional to P t according to (22). Therefore, |g q,0 | 2 (2K + 1) is also proportional to P t .…”

“…Also, changing B affects the quantity of observation data and accordingly the number of summands in (16) that equals 2K +1. In addition, by changing B, we must recompute g q,n , ∀(q, n), according to (22) and (23), for use in the construction of new E k . Figure 3 shows that the MSE may be reduced by increasing B, but there is a limit where the MSE cannot be reduced further.…”

“…This is because when ρ = 1, we have |g q,n | = |g q,0 | for all n > 0 and accordingly the Rician K factor [22] is 1/(N P −1) ≈ 0. On the other hand, the Rician distribution could occur when |g q,0 | 2…”

“…In this regard, we may note from (1) that the CFR for a specific subcarrier is a summation of independent complex zero mean circularly symmetric random variables. Hence, for large N P , the frequency response over a subcarrier could exhibit frequency flat-fading characteristics with Rayleigh or Rician distribution, the common characteristics in practical radio propagation environments [22]. The Rayleigh distribution could occur when |g q,0 | 2…”

Low complexity precoding codebook design based on DFRST for limited feedback precoded OSTBC systems

“…This precoding technique for the MIMO system can improve the system performance significantly by using the channel state information (CSI) [11][12][13][14] at the transmitter. This system model with limited feedback studied by Love and Heath in [7] has been adopted in many communication systems, such as the Long Term Evolution (LTE) [1][2][3][4] and spatial modulation [15,16].…”