A method of increasing the range of v.h.f. communication systems by multi-carrier amplitude modulation

Performance limits of coded diversity methods for transmitter antenna arrays

“…Perhaps the oldest form of scalar-coded transmitter diversity is repetition coding across orthogonal carriers [2], [10]. Unlike the frequency-division method described in Section II-D1, repetition expands bandwidth by a factor of Thus for this section only, we deviate from our assumption that bandwidth is conserved.…”

“…The -fold repetition causes a factor of in bandwidth expansion. An early example of repetition diversity using disjoint frequency bands may be found in Brinkely [2]; see also the summary in Jakes [10]. More recent examples include the rapid phase sweeping arrangements of Hattori and Hirade [8] and Weerackody [26].…”

“…To analyze the performance limits of both vector-coded and scalar-coded transmitter antenna systems, we examine the mutual information between input and output over a long block of symbols, following the approach of Ozarow, Shamai, and Wyner [18], which corresponds in an approximate sense to the maximum achievable rate of reliable communication. Formally, we define this mutual information as (2) where is the mutual information between a block of input and output symbols. The existence of this limit is straightforward to establish in all cases we consider.…”

“…This model is generally appropriate when there is no line of sight to the receiver, when there are a large number of reflected paths, and when the antenna elements are at least wavelength apart. 2 The stochastic model allows performance to be expressed probabilistically in terms of the Rayleigh statistics.…”