Miscellaneous Communications Functions

Classes
class	itpp::EXIT
	EXtrinsic Information Transfer (EXIT) chart. More...
class	itpp::Multilateration
	Multilateration class for 3D indoor localization More...
class	itpp::STC
	Space Time block Codes (STC) class. More...

Functions
bmat	itpp::graycode (int m)
	Generate Gray code of blocklength m.
int	itpp::hamming_distance (const bvec &a, const bvec &b)
	Calculate the Hamming distance between a and b.
int	itpp::weight (const bvec &a)
	Calculate the Hamming weight of a.
vec	itpp::waterfilling (const vec &alpha, double P)
	Compute the water-filling solution.

Detailed Description

Function Documentation

graycode()

ITPP_EXPORT bmat itpp::graycode

(

int

m

)

Generate Gray code of blocklength m.

The codes are contained as binary codewords {0,1} in the rows of the returned matrix. See also the gray() function in math/scalfunc.h.

Definition at line 39 of file commfunc.cpp.

References concat(), graycode(), ones_b(), reverse(), to_bmat(), and zeros_b().

Referenced by graycode(), itpp::ND_UPAM::set_M(), itpp::ND_UPSK::set_M(), itpp::ND_UQAM::set_M(), itpp::PAM::set_M(), itpp::PAM_c::set_M(), itpp::PSK::set_M(), and itpp::QAM::set_M().

hamming_distance()

ITPP_EXPORT int itpp::hamming_distance	(	const bvec &	a,
		const bvec &	b )

Calculate the Hamming distance between a and b.

Definition at line 59 of file commfunc.cpp.

References it_assert_debug.

weight()

ITPP_EXPORT int itpp::weight

(

const bvec &

a

)

Calculate the Hamming weight of a.

Definition at line 71 of file commfunc.cpp.

Referenced by itpp::Extended_Golay::decode().

waterfilling()

ITPP_EXPORT vec itpp::waterfilling	(	const vec &	alpha,
		double	P )

Compute the water-filling solution.

This function computes the solution of the water-filling problem

\[\max_{p_0,...,p_{n-1}} \sum_{i=0}^{n-1} \log\left(1+p_i\alpha_i\right) \]

subject to

\[\sum_{i=0}^{n-1} p_i \le P \]

Parameters

alpha	vector of \(\alpha_0,...,\alpha_{n-1}\) gains (must have strictly positive elements)
P	power constraint

Returns

vector of power allocations \(p_0,...,p_{n-1}\)

The computational complexity of the method is \(O(n^2)\) at most

Definition at line 82 of file commfunc.cpp.

References it_assert, and length().