{'fraction_non_alphanumeric': 0.024777006937561942, 'fraction_numerical': 0.0, 'mean_word_length': 5.516129032258065, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Evaluation of Space-Time Coded MIMO Transmi

In this paper we evaluate the bit error ratio (BER) performance of the space-time coded multipleinput-multiple-output (MIMO) transmission using measured indoor radio channels. Based on a novel measurement-based antenna test bed, we compute channel matrices for three different MIMO antenna configurations designed for WLAN-type application. We focus on four main points, namely, the effect of the power imbalance between the channel coefficients, the effect of spatial correlation, the influence of antenna orientation and selection combining (SC) at the receiver. Because of nonuniform directions of arrival of realistic radio channels, directional nonoverlapping antenna patterns cause power imbalances between MIMO channel coefficients resulting in BER degradation. For an array with directional overlapping patterns, the BER performance is even worse due to sensitivity to antenna orientation. The effect of spatial correlation on the BER is found to be small.