Diversity Analysis of Bit-Interleaved Coded Multiple Beamforming

TL;DR

This paper extends the diversity analysis of BICMB to general spatial interleavers, introduces a transfer function method to determine diversity order, and provides design guidelines supported by simulations.

Contribution

It removes previous design constraints on spatial interleavers and introduces a transfer function approach to quantify diversity order in BICMB.

Findings

Diversity order depends on a parameter Qmax from the code and de-multiplexer.

Qmax can be accurately determined using the transfer function method.

Simulation results verify the theoretical diversity analysis.

Abstract

In this paper, diversity analysis of bit-interleaved coded multiple beamforming (BICMB) is extended to the case of general spatial interleavers, removing a condition on their previously known design criteria and quantifying the resulting diversity order. The diversity order is determined by a parameter Qmax which is inherited from the convolutional code and the spatial de-multiplexer used in BICMB. We introduce a method to find this parameter by employing a transfer function approach as in finding the weight spectrum of a convolutional code. By using this method, several Qmax values are shown and verified to be identical with the results from a computer search. The diversity analysis and the method to find the parameter are supported by simulation results. By using the Singleton bound, we also show that Qmax is lower bounded by the product of the number of streams and the code rate of an encoder. The design rule of the spatial de-multiplexer for a given convolutional code is proposed to meet the condition on the maximum achievable diversity order.