Performance and Optimization of Switched Diversity Systems for the Detection of Signals with Rayleigh Fading

Abstract

Abstmct-The performance and optimization of switched diversity systems are considered.First, the one-dimensional distribution and probability density functions of the envelope of the received signal are obtained for three different switching strategies. This information is used to obtain the average probability of bit error for the case of non-coherent detection of binary FSK signals with Rayleigh fading envelopes and additive white Gaussian noise. The optimization of two of these switching strategies is then considered, and it is shown that by proper selection of switching thresholds, the average probability of bit error during detection can be minimized. It is also shown that these optimized switching strategies yield a significant improvement in performance over non-diversity systems and can approach the performance of more complex receivers such as maximal ratio combining. Computer simulations of switched diversity sytems using a practical field model are used to verify the analysis.

Group Switch-and-Stay Combining with Branch Partition for Space Diversity

“…Traditional combining schemes, such as MRC or SC, will use all available diversity branches, and thus have higher implementation complexity [2]. To reduce the complexity, switch-based SSC has been considered [3]- [5], where no real combiner is required. The SSC is particularly valuable for mobile stations that have limited resource and power, and it has been applied to cooperative diversity systems [6]- [8].…”

Switch‐and‐examine combining with different new switch statistics for diversity over Rayleigh fading channels

“…Traditional combining techniques are based on the signal-to-noise ratio (SNR) of diversity branches and can be categorized as the SNR-based diversity scheme that includes the traditional maximal-ratio combining, equal-gain combining, selection combining (SC), and switch combining [2,3].…”

“…In contrast, the switch combining scheme only needs to monitor the SNR of the single used branch and compare it to a preset threshold within a guard time-slot. Thus, among different combining methods, the switch combining has the lowest implementation complexity [2,3], which is valuable for mobile stations in some practical cases [4][5][6][7][8]. A switch combining scheme can also be applied to free-space optical wireless communication systems [9], or be incorporated with multiple transmission antennas for MIMO systems [10].…”

Switching rate and receiver performance of binary modulations with the selection‐and‐stay combining over independent and correlated Nakagami‐m fading channels

“…To implement a low-complexity diversity system, the switch-based combining has been considered for wireless systems [3][4][5]. In a switch-based combining system, the receiver only needs to continuously estimate the power of the single diversity branch currently in use.…”

“…In [5], two typical switch-based methods, dual-branch switch-and-stay combining (SSC) and switch-and-examine combining (SEC), were proposed, where binary coherent FSK (CFSK) on independent Rayleigh fading channels was analyzed. In the SSC system [5], the estimated signal power of the used branch is compared to a preset threshold, and the receiver will switch to the…”