Hello,

I am trying to solve a mixed integer linear programming problem using CVX Gurobi. I can find a feasible solution of the problem by hand. However, CVX Gurobi is showing me errors.

I will show my code and the CVX error here. I am sorry for this long post but I am just trying to explain the problem. If anyone thinks that a feasible solution will be helpful, please let me know. I can provide that later.

Any help will be appreciated.

Thanks,

Nazmul

CVX Original Code:

cvx_solver Gurobi

cvx_begin

%% MaxPowerMobile(1), sLMobile(2x2), sUMobile(2x2), betaMobile(2x2), NodeAccessGain(2x2), %% N0(1) and W(1) are predefined constants

variables K FlowMobile(NodeNum,PortFreqNum) PowerMobile(NodeNum, PortFreqNum) …

SINRMobile(NodeNum, PortFreqNum)

variable DecisionMobile(NodeNum, PortFreqNum) binary

maximize K

subject to

```
sum(FlowMobile,2) >= K ;
sum(DecisionMobile,1) <= 1 ;
sum(DecisionMobile,2) <= 1 ;
SINRMobile >= SINR_Thres * DecisionMobile ;
(NodeAccessGain .* PowerMobile) >= N0 * SINRMobile ;
sum(PowerMobile,2) <= MaxPowerMobile ;
PowerMobile <= MaxPowerMobile * DecisionMobile ;
(1 + sLMobile) .* FlowMobile - W * SINRMobile <= W * (1 + sLMobile) .* (log(1 + sLMobile) - 1) + W ;
(1 + betaMobile) .* FlowMobile - W * SINRMobile <= W * (1 + betaMobile) .* (log(1 + betaMobile) - 1) + W ;
(1 + sUMobile) .* FlowMobile - W * SINRMobile <= W * (1 + sUMobile) .* (log(1 + sUMobile) - 1) + W ;
FlowMobile >= 0 ;
K >= 0 ;
PowerMobile >= 0 ;
SINRMobile >= 0 ;
```

cvx_end

CVX_Error message:

## Calling Gurobi: 49 variables, 32 equality constraints

Optimize a model with 32 rows, 49 columns and 98 nonzeros

Found heuristic solution: objective 0

Presolve removed 28 rows and 48 columns

Presolve time: 0.00s

Explored 0 nodes (0 simplex iterations) in 0.00 seconds

Thread count was 1 (of 4 available processors)

Model is unbounded

Best objective 0.000000000000e+00, best bound -, gap -

??? Error using ==> solve at 259

An unexpected error was encountered:

Error using ==> gurobi

Gurobi error 10005: Unable to retrieve attribute 'ObjVal’

Error in ==> cvx_run_solver at 45

[ varargout{1:nargout} ] = sfunc( inputs{:} );

Error in ==> D: